- Welcome to the Huberman Lab Podcast, where we discuss science
and science based tools for everyday life. I'm Andrew Huberman, and I'm a professor of
neurobiology and ophthalmology at Stanford School of Medicine. Today I have the pleasure of introducing Dr. Matthew Walker as our guest
on the Huberman Lab podcast. Dr. Walker is a professor of
neuroscience and psychology at the University of California, Berkeley. There, his laboratory studies sleep. They study why we sleep, what occurs during sleep, such
as dreams and why we dream, learning during sleep, as well as the consequences
of getting insufficient or poor quality sleep on waking states. Dr. Walker is also the author of the international best
selling book "Why We Sleep". Our discussion today is an
absolutely fascinating one for anyone that's interested in sleep, learning, or human
performance of any kind. Dr. Walker teaches us how
to get better at sleeping. He also discusses naps, whether or not we should
or should not nap, whether or not we can
compensate for lost sleep, and if so how to best do that. We discuss behavioral protocols and interactions with light,
temperature, supplementation, food, exercise, sex, all the
variables that can impact this incredible state of mind
and body that we call sleep. During my scientific career, I've read many papers about sleep and attended many seminars about sleep yet my discussion with Dr. Walker today revealed to me more about
sleep, sleep science and how to get better at sleeping than all of those papers
and seminars combined. I'm also delighted to share that Dr. Walker has started a podcast. That podcast entitled
"The Matt Walker Podcast", releases its first episode this month and is going to teach all about sleep, and how to get better at sleeping. So be sure to check out
the Matt Walker podcast on Apple, Spotify or wherever
you listen to podcasts. Before we begin, I'd like to mention that this podcast is separate from my teaching
and research roles at Stanford. It is however part of my desire and effort to bring zero cost of consumer information about science and science related tools to the general public. In keeping with that theme, I'd like to thank the
sponsors of today's podcast. Our first sponsor is ROKA. ROKA makes sunglasses and eyeglasses that are of the absolutely
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for 20% off your order. And now my discussion
with Dr. Matt Walker. Great to finally meet you in person. - Wonderful to connect. I mean, it's been too long, but I suspect it would
have been a shorter time before we'd met lest the
pandemic, thank you for coming up. - No, thank you, yeah, I'm delighted that we're finally
sitting down face to face. I've been tracking your work
both in the internet sphere, and I read your book and loved it. And also from the perspective of science, you actually came to
Stanford couple of years ago and gave a lecture for BrainMind. - Oh, yeah, yeah, yeah, yeah. - And there, of course,
you talked about sleep and its utility and its challenges and how to conquer it, so to speak. Let's start off very basic, what is sleep? - Sleep is probably the
single most effective thing you can do to reset your
brain and body health. So that's a functional
answer in terms of, you know, what is sleep in terms of its benefits. Sleep as a process though, is an incredibly complex
physiological ballet. And if you were to recognize or see what happens to your brain and your body at night, during sleep, you would be blown away. And the paradox is that most of us, and I would think this too, you know, if I wasn't a sleep scientist, we go to bed, we lose consciousness
for seven to nine hours, and then we sort of
wake up in the morning, and we generally feel better. And in some ways that denies the physiological and
biological beauty of sleep. So upstairs in your brain, when you're going through these
different stages of sleep, the changes in brainwave activity are far more dramatic
than those that we see when we're awake. And we can speak about deep
sleep and what happens there, REM sleep is a fascinating time, which is another stage of sleep, often called dream sleep, which is rapid eye movement sleep, that stage of sleep
some parts of your brain are up to 30%, more active
than when you're awake. So again, it's kind of violating this idea that our mind is dormant. And our body is just simply
quiescent and resting. So I would happy to just
sort of double click on either one of those, and also what changes in the body as well. But it is an intense evolutionary adaptive benefit and system. That said, though, I would almost push back
against an evolved system when we think about the question
of sleep and what sleep is. Our assumption has always
been that we evolved to sleep. And I've actually questioned that and I have no way to get in a time capsule and go back and prove this, but what if we started off sleeping, and it was from sleep,
that wakefulness emerged? Why do we assume that
it's the other way around? And I think there's probably some really good evidence that sleep may have been the proto state, that it was the basic
fundamental living state. And when we became awake, as it were, we always had to return to sleep. You know, in some ways, at that point, sleep was the price that
we paid for wakefulness. And that's another way of
describing what sleep is. But again, I think it sort of denies that the active state of sleep, it's not a passive state of sleep either. And then finally, you can say what is sleep across different species? And in us human beings, and in all mammalian species
and avian species as well, sleep is broadly separated
into these two main types. And we've got non rapid eye
movement sleep on the one hand, and then we've got rapid eye
movement sleep on the other. And we can speak about how they unfold across a night and their architecture because it's not just
intellectually interesting from the perspective of what sleep is, it's also practically
impactful for our daily lives. And I'd love to sort of
go down that route too. But you navigate, you tell me I can. - No, no, let's definitely
go down that route. So you mentioned how active the brain is, during certain phases of sleep. When I was coming up in science, REM sleep, rapid eye movement sleep was referred to as paradoxical sleep, is that still a good
way to think about it? Paradoxical because
the brain is so active, and yet we are essentially
paralyzed, correct? - Yeah, it really is a paradox. And where that came from was simply the brainwave recordings, that if all I'm measuring about you, is your brainwave activity, it's very difficult for me sitting outside of the
sleep laboratory room to figure out, are you awake, or are you in REM sleep? Because those two
patterns of brain activity are so close to one another, you can't discriminate between them. Yet, the paradox is
that when you are awake, I go in there and you're
sort of sitting up, you're clearly conscious and awake. But yet, when you go into REM sleep, you are completely paralyzed. And that's one of the I think
that's part of the paradox. But the paradox really just comes down to two dramatically different
conscious states. Yet, brain activity is dramatically more similar than different. And the way I can figure out which of the two you are in is by measuring two other signals, the activity from your eyes and the activity from your muscles. So when we're awake, we will occasionally have these blinks, and we'll have sort of seek heads. But during REM sleep, you have these really bizarre, horizontal shuttling eye
movements that occur. And that's where the name comes from rapid eye movements. - Are they always horizontal? - Mostly, they are horizontal.
- That's interesting. - And that's one of the ways
that we can differentiate them from other waking eye movement activity, 'cause it's not always like it can be sometimes horizontal, but can also have diagonal and
also vertical in that plane. But then the muscle activity
is the real dead giveaway, just before you enter REM sleep, your brainstem, which
is where the dynamics of non REM and REM are essentially played out and then expressed upstairs in the cortex and downstairs in the body, when we go into REM sleep, and just a few seconds
before that happens, the brainstem sends a signal all the way down the spinal cord. And it communicates with what are called the alpha motor neurons in the spinal cord which control the
voluntary skeletal muscles. And it's a signal of paralysis. And when you go into dream sleep, you are locked into a
physical incarceration of your own body.
- Amazing. - You know, why would Mother
Nature do such a thing? And it's in some ways very simple. The brain paralyzes the body so that the mind can dream safely. Because think about how quickly we would have all been
popped out of the gene pool. You know, if I think I'm, you know, one of the best skydivers
who can just simply fly, and I've had some times
those dreams, too, you know, and I get up on my apartment
window, and I leap out. - You're done.
- You're done, you know. So that's one of the sort of that's part of the paradox of REM sleep, both it's brain activity similarity, despite the behavioral
state being so different and this bizarre lockdown
of the sort of brain of the body itself. Now, of course, the involuntary muscles thankfully aren't paralyzed. So you keep breathing,
your heart keeps beating. - Is this why men have
erections during REM sleep, and women have vaginal
lubrication during sleep? - That's one of the reasons part of the other reason though there is because of the autonomic activity. So there is a nervous, a part of our nervous system called the autonomic nervous system, and it controls many of
the automatic behaviors. And some of those are aspects of our reproductive facilities. During REM sleep, what we later discovered is that you go through these bizarre what we call autonomic
storms, which sounds dramatic, but it actually is when you measure them. That you'll go through periods where your heart rate,
decelerates and drops and your blood pressure goes down and then utterly randomly, your heart rate accelerates dramatically, and what we call the
fight or flight branch of the autonomic nervous system or the sympathetic nervous system, badly named 'cause it's
anything but sympathetic, it's very aggravating, that all of a sudden fires up and then it shuts down again. And it's not in any regular way. And it's when you get
those autonomic storms, you get very activated from
a physiologic perspective that you can have these erections and you have vaginal discharge et cetera. - But you're totally paralyzed? - But you are still paralyzed. There are only two voluntary muscle groups that are speared from
the paralysis, bizarre. One, your extra ocular muscles, because if they were paralyzed, you wouldn't be able to
have rapid eye movements. And the other that we later discovered was the inner ear muscle. And we've got no good understanding as to why those two muscles groups are speared from the paralysis. It may have something
to do with cranial nerve but I don't think it's that, I think it's perhaps something
more sensory related. Some people have argued that the reason the eyeballs
are speared from the paralysis is because if your eyeballs are left for long periods of time, inactive, you may get things such
as oxygen sort of issues in the aqueous or vitreous humor. And so the eyeballs have to keep draining. - The drainage systems of the anterior eye are made to require movement.
- Exactly. - People with glaucoma
have deficits in drainage through the anterior chamber,
but there I'm speculating. I'm also speculating, when I ask this, I would imagine that
there are states in waking that also resemble slow wave sleep, or rather that there are states that slow wave sleep also
resembles waking states. You've beautifully
illustrated how REM sleep can mimic some of the
more active brain states that we achieve in waking. What sort of waking state
that I might have experienced or experience on a daily basis might look similar to slow wave sleep, non REM sleep, if any? - It's a genius way of thinking about it turns the tables I love it. We almost never see anything
like the true ultra slow waves of deep non REM sleep. So we spoke about these
two stages non REM and REM. Non REM is further subdivided
into four separate stages, stages, one through four, increasing in their depth of sleep. So stages three and four
that's what we typically call deep non REM sleep. Stages one and two light non REM. - So maybe take me
through the arc of a night just so that. So I put my head down, well, for you, what time do
you normally go to sleep? - So I'm usually sort of
around about 10:30pm guy. And usually I'll naturally wake up sort of a little bit before 7:00, sometimes before 6:45 or 7:00, I have an alarm set for 7:04am. - You heard it here, folks Matt Walker does use an alarm clock. - I rarely, rarely I'm usually sort of. - He doesn't recommend
it, but he does use it. - Yeah, I usually.
- You're human after all. - Oh, I am so human. And I've had my sleep issues and I'd love to speak about that too. But it's only just, you know,
in the event that, you know, 'cause I like to keep regularity too. You've got to keep those
two things in balance. And 7:04 just because, you
know, why not be idiosyncratic. I don't know why we always set things on these hot numbers. So yep so when you. - So you go to sleep around 10:30, so using you as an example, because I imagine a number of people go to sleep at different times. But 10:30 is about when I
go to sleep, 11 is for me. But so you go to sleep at 10:30, so for that first, let's
say three hours of sleep, what does the architecture
of that sleep look like as compared to the last three hours of your sleep before morning? - Yeah, so I should note
that that sort of, you know, 10:30 to 7:00 that's just
based on my chronotype and my preferential it's
different for different people. I'm not suggesting that
that's the perfect sweet spot for humanity's sleep. It's just my natural sweet spot. - But I imagine most
people probably go to sleep somewhere between 10pm and midnight. - It's somewhere between 9 and midnight. - And most probably wake
up between 5am and 7am or 5:30 and 7:30. - Yeah, yeah at least in if you look at sort of
first world nations, that's a typical sleep profile. So when I first fall asleep, I'll go into the light
stages of non REM sleep stages one and two of non REM. And then I'll start to descend down into the deeper stages of non REM sleep. So after about maybe 20 minutes, I'm starting to head down
into stage three non REM and then into stage four non REM sleep. And as I'm starting to fall asleep, as I've cast off from the usually with me, murky waters of wakefulness, and I'm in the shallows of
sleep stages one and two, my heart rate starts to drop a little bit. And then my brainwave pattern
activity starts to slow down. Normally when I'm awake,
it's going up and down, maybe 20, 30, 40, 50 times a second. As I'm going into light, non REM sleep, it will slow down to maybe 15, 20 and then really starts to slow down down to about sort of 10
or eight cycles per second, eight cycle waves per second. Then as I'm starting to move into stages three and four, non REM sleep, several remarkable things happen. All of a sudden, my heart rate
really does start to drop. Oh, and I'll come back to temperature, I'm going to write temperature down 'cause I always forget these things. Now I'm solidly in the
foothills of middle age. So as I'm starting to go
into those deeper stages of non REM sleep, all of a sudden, hundreds of thousands
of cells in my cortex all decide to fire together and then they all go silent together. And it's this remarkable
physiological coordination of the likes that we just don't see at during any other brain state. - That's really interesting, other than recordings
from the brains of animals and a little bit from humans, I don't think I've ever
seen the entire cortex or even entire regions of
cortex light up like that. - Yeah, it's stunning. It's almost like this
beautiful sort of mantra chant, or this sort of, you
know, it's a slow inhale and then a meditative
exhale, inhale, exhale. And these waves are just
enormous in their size. - And the body is capable
of movement at this time, there is no paralysis. - There is no paralysis,
but for the most part, muscle tone has also
dropped significantly. - Interesting.
- At that point. And then you will, or I will then stay there for about another 20 or 30 minutes. So now I'm maybe 60, or 70 minutes into my first sleep cycle. And then I'll start to rise back up, back up into stage two non REM sleep. And then after about 80 or so minutes, I'll pop up, and I'll have
a short REM sleep period, and then back down, I go
again, down into non REM, up into REM. And you do that reliably, repeatedly, and I will be doing that, and
I do do that every 90 minutes. At least that's the
average for most adults, it's different in different species. What changes to your question is the ratio of non REM to REM
within that 90 minute cycle as you move across the night. And what I mean by this is, in the first half of the night, the majority of those 90 minute cycles are comprised of a lot
of deep non REM sleep, that's when I get my stage three and four of deep non REM sleep. Once I push through to the
second half of the night, now that seesaw balance changes. And instead, the majority
of those 90 minute cycles are comprised either of this lighter form of non REM sleep, stage two non REM sleep, and much more and increasingly more rapid eye movement sleep. And the implication that I was sort of speaking
about pragmatically is, let's say that I have to, and I usually never do early
morning flights or red eyes, just because I'm a mess if that happens, I'm not suggesting other people shouldn't. - I'm suggesting people not not do that. Every time I've taken a
red eye or I've done that two or three days later, I get some sort of general
feeling of malaise, my brain doesn't work as well, I think red eyes should be abolished. For the pilots too I mean, and for the. - And we can speak about
those, there's data. - And for the emergency room, I mean, long shifts have been
shown to lead to, you know, physician induced errors that
lead to a lot of fatalities. I mean, there are a lot of
reasons why staying up too long, or being up at the wrong times, if you're not adapted
to it is just terrible. - You have the data and all
of those cases, you know, particularly physicians too there was some recent data
looking at suicidality. And the rates of suicide
in training physicians are, you know, far, far above the norm. And I don't suspect that, you know, the schedules are helping them I suspect that sleep is a missing part of that explanatory equation, but. - I teach medical students
and they they're phenomenal, but yeah, they're under
extremely challenged conditions. - We shouldn't put them
under those conditions. - [Andrew] No, it's not optimizing
performance, I have one. - But sorry, I was sorry. - No, no, this is important. These it's an important digression. I have one question, which is you're saying
that as across the night, a greater percentage of
these 90 minute cycles are going to be occupied by REM sleep as you progress through the night. I'm aware that, based
on work that you've done and from your public
education efforts and others that we have so called circadian forces, and we have other forces that are driving when we sleep and when we
want to sleep, etcetera. Without going into the details of those, I've a simple question, the experiment is the following. Let's say, God forbid, you are prevented from going
to sleep at your normal time and you stay up for the
four hours or five hours that normally you would be in
predominantly slow wave sleep. - If let's say you finally
get to lie down at 3am a time when normally your
sleep would be occupied mostly by rapid eye movement sleep, will you experience a greater percentage of rapid eye movement sleep because of these so
called circadian forces, meaning that's what's
appropriate for that time? Or will your system need to start at the beginning of the race that were, as I'm referring to it,
that we're calling sleep? And for if that's not clear to anybody, basically, what I'm asking is, if you are forced to skip the slow wave sleep part of the night, will your system leap into
rapid eye movement sleep? Or does it have to start at the beginning and get slow wave sleep first? In other words, does one sleep state drive the entry to the next sleep state? - Great question, so there
is some degree of reciprocity between the sleep states I should note that when we drive one of those up, we often but not always
see a change in the other. There are some pharmacologies
that have shown an independence to that. And we've also played around
with things like temperature, and sometimes you can, you know, nudge one and not seem to
upset or perturb the other. But to your, I think, lovely point, the answer is, it's a mix, but it's mostly the latter. Meaning you will mostly go
into your REM sleep phases, and be significantly
deficient in your deep sleep. So just because I start
my sleep cycle at 3am, rather than at 10:30pm, it doesn't mean that my brain just says, well, I've got a program, and I'm just going to run the program, and the way the program runs is that we always start with a first couple of hours of deep sleep. So we're just going to begin
act number one, scene one, it doesn't do that. Now, I will get some
deep sleep to begin with and part of that is just
because of how sleep works. Based on how long I've been awake, longer I'm awake, there is a significantly
greater pressure for deep sleep. But we actually use exactly
what you just described as an experimental technique to selectively deprive people of one of those stages
of sleep or the other. So we will do first half
of the night deprivation, and then let you sleep the second half. So that means that you will
be mostly deep sleep deprived, and you will still get
mostly all of your REM sleep. And then we switch it, so you only get your first four hours, which means you will mostly
get deep non REM sleep, but you will get almost no REM sleep. So in both of those groups, they've both had four hours of sleep. So the difference between them in terms of an experimental outcome is not the sleep time because they both slept
for the same amount. It's the contribution of
those different stages. Now, we actually have more elegant methods for sort of selectively going in there and scooping out
different stages of sleep. But that's the way we
used to do it old school was just using this timing difference. - And who suffers more? Those that lack the early phase, and were those that lack the
later phase of the night sleep? In other words, if I have to sleep only four
hours for whatever reason, am I better off getting the
early part of the night's sleep or the second half of the night sleep? - Depends on what the outcome measure is. - So that gets right to the differences between slow wave sleep and REM. - Right.
- I was probably misinformed. But my understanding a
very crude understanding I should say before. - I very much doubt I'll
contrary with someone like you. - Which is that's very nice of you. The first part of the night the slow wave sleep is
restorative to the musculature to motor learning, and
that the dream content tends to be less emotional. The second half of the night, being more emotional dreams and sort of the unpairing
of the emotional load of our previous day and other experiences. So in other words, if I were to deprive
myself, excuse me of REM, I would be hyper emotional, not maybe not as settled with the kind of experiences of my life. Whereas if I deprive
myself of slow wave sleep, I would feel a more physical malaise. Is that correct? Or is that far too simple? And if it is too simple, please tell me where I'm wrong? - No, I think much of that is correct. And it's sort of that plus. So for example, during deep non REM sleep, that's where we get this. It's almost a form of natural
blood pressure medication. And so when I take that
away from you, the next day, we're usually going to
see autonomic dysfunction, we're usually going to see abnormalities in heart rate blood pressure. We also know that during
deep non REM sleep, that there is a certain
control of specific hormones. For example, we know that
the insulin regulation of sort of metabolism, meaning how will you look from a regulated blood sugar perspective versus dysregulated, pre
diabetic look of profile. That's where deep sleep seems to matter if we selectively deprive
you of that we can see. - Growth hormone.
- Growth hormone is different actually. So that's a beautiful demonstration where growth hormone seems to
be more REM sleep dependent. And that's why we can come
on to the effects of alcohol and there's some really impressive frightening data on alcohol and it's disruption of sleep. But then we also know testosterone, peak levels of testosterone
happen during REM sleep. - So the second half of
the night, essentially. - Which is the second half of the night. So it really just means that the, your profile of mental
and physical dysfunction will be different under
both of those conditions. Which one would you prefer? I would prefer neither of them. And it really depends on what
you're trying to optimize for. So it's just so complicated, sleep is just so pluripotent, you know, it's so physiologically systemic, that it's almost impossible not to undergo one of those two things, just deep sleep deprivation, or just REM sleep deprivation, and not show a profile that you would really prefer to avoid. And that's the reason from
an evolutionary standpoint, that we've preserved
those stages of sleep. I mean, sleep is just
so idiotic, you know, from an evolutionary perspective. - Or maybe waking is idiotic. - Or waking is, you know, well, yeah. - Based on your previous idea. - Who've you been talking to? I think that comment
is very specific to me. Yeah, I am normally always
an idiot when working. But I think this idea
that sleep, you know, is so profoundly detrimental to us, if you were to take it
at face value, you know, you're not finding a mate,
you're not reproducing, you're not foraging for food, you're not caring for you're young and worst of all, you're
vulnerable to predation, on any one of those grounds sleep probably should have
been selected against. But it wasn't sleep has fought
its way through heroically every step along the evolutionary path. And therefore, every sleep
stage has also survived as best we can tell. What that means is that
those are non negotiable. If mother nature had found a way to even just sort of, you know, thin slice some of that sleep from us, there would have been vast,
I'm sure evolutionary benefits, but looks as though she hasn't. And I'm usually in favor of her wisdom after 3.6 million years, so. - Yeah, it's incredible. I want to introduce a
another Gedankenexperiment, other thought experiment. So in this arc of the night, slow wave sleep predominates
early in the night, and then REM sleep. There's a scenario that many people including myself experience
on a regular basis. Which is they go to
sleep, sleeping just fine, three, four hours into it, they wake up. They wake up, for whatever
reason, maybe there was a noise, maybe the temperature isn't right, we will certainly talk about
sleep hygiene, etcetera. They get up, they go to the restroom, they might flip on the
lights, they might not, they'll get back in bed hopefully they're not
picking up their phone and starting to browse
and wake up the brain through various mechanisms light and cognitive stimulation, etcetera. They go back to sleep, let's
say after about 10, 15 minutes, they're able to fall back asleep. And then they sleep till
their more typical wake time. How detrimental is that wake up episode or event in terms of
longevity, learning, et cetera? I would love to sleep the entire
night through every night, but most nights I don't. And yet, I feel pretty
good throughout the day, some days better than others. So if you were to kind of
evaluate that waking episode, and compare it to sleeping
the whole night through, what are your your thoughts on that? - So I think if you're waking up sort of frequently, as you're describing, I would probably get your estate in order because my guess is within the next year, you're going to be you're
going to be done for, no I'm kidding you. Absolutely kidding you. It is perfectly natural and normal, particularly as we progress
with age, you know, children tend to have typically
more continuous sleep. Now it's not that they aren't waking up for brief periods of time they are and in fact, we all do. When we come out the other
end of our sleep cycle at the end of our REM sleep
period of the 90 minute cycle, almost everybody wakes up and we make a postural
movement, we turn over because we've been paralyzed for so long and the body will also like to shift it's weight or position. - Do we ever look around? Ever open our eyes and look around? - You, sometimes people
will open their eyes, but usually it's only for
a brief period of time and they usually never commit
those awakenings to memory. Your situation and it's
my situation as well, I usually now at this stage of life, I don't sleep through the night. I'll usually have a bathroom
break and then I'll come back. That's perfectly normal. We tend to forget that in sleep science, we think of sleep efficiency so of the total amount of
time that you're in bed, how much of that percent
time is spent asleep? And we usually look to
numbers that are above 85%, or more as a healthy sleep efficiency. So if you're to think about me going to bed and I spend, you know, let's say, eight and a quarter, eight and a half hours of time in bed, with a normal, healthy sleep efficiency, I still may be only sleeping a total of seven and a half hours, or seven and three quarter hours. Meaning that I'm going
to be awake in total, not in one long about, but I'm going to be awake
for upwards of 30 minutes, net some time. Sometimes that can be after
a 10 minute, you know, dalliance after having
gone to the bathroom, and I'm just gradually
drifting back off again. Other times, it will just
be for a couple of minutes. And most of those you don't commit. So I think we need to stop, we don't need to get too
worried about, you know, periods of time awake, just because we're not
sleeping throughout the night. I would love to do that, too. And I remember when that used to happen, and it still happens occasionally. - Every once in a while, it
feels great when it does happen. - And it's a lovely thing. - It's a surprise right? Like oh my goodness I slept
through the whole night. - It is now a surprise,
yeah it is a surprise. But for the most part, I think we can be more relaxed about that where we have to be a bit
more attentive, though, is if you're spending
long periods of time, not being able to get back to sleep. And usually we define that by saying, if it's been 20, 25 minutes, normally, that's the time
when we would really say okay, let's explore this, what's going on? Let's see what's happening. The other thing is if it's
happening very frequently, so even if you're, you know, not awake for 25 minutes stretches, but you're finding yourself waking up and being consciously
aware that you've woken up for maybe six, seven or eight
times throughout the night and your sleep is very
what we call fragmented the great science of sleep
in the past five or 10 years has been yes, quantity is important, but quality is just as important. And you can't have one without the other in terms of a good
beneficial next day outcome. You can't just get four hours of sleep, but brilliant quality of
sleep and be unimpaired. Nor can you get eight hours of sleep, but have very poor quality of sleep and be unimpaired the next day. So that's why I just
sort of want to asterisk, this idea of let's not get too worried about waking up and
having some time awake, that's perfectly normal and natural. But if it's happening very
frequently throughout the night, or those periods of time, or long stretches of time,
upwards of 25 minutes, then let's look into it. - Well, I can assure you
just helped a lot of people feel better about this waking up episode that I and many other people experience. - I hope so 'cause I think
it's really important that we, you know, I think I've been desperately
guilty of perhaps, you know, early on being too
puritanical about, you know, sleep and I've retrospected, and I've tried to explore why
this was the case, you know, it was almost sleep or
else, dot, dot, dot. And at the time when I was
starting to write the book, which was back in 2016, you know, sleep was still a neglected stepsister in the health conversation of today. And I could see all of the, - That has certainly changed. - And it's changing, you know, and not because it's my efforts, but because of all of my colleagues. - I would say, well, it's great that you give attribution to the other people involved. And of course, it's a big field. But I think you've done a
great service by cueing people to the importance of this state, not just for avoiding
troublesome outcomes, but also for optimizing
their waking state. It's really, you know, I view sleep as this
period that feels good, but we're not aware of how it feels when we're in it necessarily. It has tremendous benefits
when you're doing it well, so to speak, and it has tremendous
deficits when we're not. And I think it was an
important thing for you to do to cue people to this issue. And I would say mission accomplished, that people are aware
of the need for sleep. I think that knowing that waking up in the middle of the night is normal, provided it's not too frequent is great and will also help people who may have been overly
concerned about that. I do want to use this as an opportunity to raise something about the
so called Uberman schedule not to be confused with
the Huberman schedule. Fortunately, no one
has confused those yet. Some years ago, there
was a discussion about the so called Uberman schedule, meaning the Superman schedule. So that's Huberman without an H, which I have nothing to do with. If you read your Nietzsche
this will have a subtext. But regardless, the Uberman
schedule, as I understand is one in which the person elects to sleep in 90 minute, bouts spread
throughout the day and night, in an attempt to get more productivity and or reduce their overall sleep need. There was a paper published recently that explored whether or not
this is good or bad for us. Maybe you just give us the
take home message on that. - Yes, so these Uberman like schedules and there's lots of
different forms of that, they tried to essentially
pie chart the 24 hour period, into short bouts of sleep
with some shorter or no, well, slightly longer periods of wakefulness, then short bouts of
sleep then wakefulness. You know, you're, I sort
of made it, I think a quip, it's almost like you're
sleeping like a baby, you know, 'cause that's the way
that babies will sleep. - In 90 minute naps. - That they will have, you
know, these brief naps, then they're awake, then they're asleep then they're awake. And to the chagrin of
parents across the night, it's basically the same,
they're awake, they're asleep, they're awake, they're asleep. And that's more the schedule that these types of
protocols have suggested. And there was a really
great comprehensive review that found not only that they
weren't necessarily helpful, but they were actually
really quite detrimental. And on almost every performance metric, whether it be task performance, whether it be physiological
outcome measures, whether it even be the
quality of the sleep that they were having, when they were trying to get it, all of those were in a downward direction. And it's not surprising
if you look at your the way that your
physiology is programmed, if you look at the way your
circadian rhythm is programmed, none of that screams to us that we should be sleeping in that way. - Well, I'm chuckling because we always hear sleep like a baby. This is how babies sleep. And I would say don't sleep like a baby, sleep like an adult be an adult,
get your solid eight hours. - It's Billy Crystal's
line, he was, you know, a long standing suffering insomniac, he says I sleep like a baby,
I'm awake every 20 minutes. You know, and I think this is another one of
those demonstrations that when you fight
biology, you normally lose. And the way you know you've lost is disease, sickness and impairment. And I think if you sleep, in accordance with the
natural biological edict that we've all been given, life tends to be both
have a higher quality and a longer duration. - Yeah, I agree. Along those lines, as a vision scientists, I've been very excited by the work on these non image
forming cells in the eye, the so called melanopsin cells that inform the brain about
circadian time of day. And I'm a big proponent of
people getting some sunlight, ideally sunlight, but
other forms of bright light in their eyes early in the day and when they want to be awake. Essentially, during the phase of their 24 hour circadian cycle when temperature is rising, and then starting to get
less light in their eyes as our temperature is going down in terms of later in the
day and in the evening. Are there any adjustments
to that general theme that you'd like to add? Or is in any way? - No, I think that's exactly
what we recommend right now. Which is try to get at
least 30 to 40 minutes of exposure to some kind
of natural daylight. Now, there may be parts of the
world where, you know, it's. - You're from your from a
rather cloudy part of the world. - I am from Liverpool, England, and the Northwest of England is not known for its beach resorts and fine weather. I remember I sort of, I
went back home for a trip when I'd first been out in California, and I thought, why is the sky so low? Just you know, constantly
we joke that in the UK, we usually have nine months of bad weather and then three months of Winter. And then that's your entire
year in terms of climate. But to come to your point,
you're exactly right, try to get that daylight. Now it can be you know,
working next to a window and you're getting that natural sunlight. But that natural sunlight is
even on a cloudy day in England is usually far more potent than anything that you'll
get from indoor lighting, despite you thinking sort
of from a perception wise, maybe the much closer than I would think. - Yeah, I've been I'm sorry to interrupt. I've been a big proponent of there's a an app called
Light Meter, which will it's a free app, I have
nothing to do with it that will allow you to get a pretty decent
measurement of the amount of light energy coming toward you. And if you hold it up to a cloudy morning, where you don't think it's very bright out kind of a dismal day, you'll notice that
there'll be 1,000, 2,000, even you know, 5,000 Lux, Lux just being a measure
of brightness, of course. And then you can point
the same light meter toward an indoor light
that seems very bright and very intense and it'll say 500 Lux and you realize that the
intensity as we gauge it, perceptually is not really
what the system is receiving. So outdoor light is key. How do you get this natural stimulation? Or I should just say light
stimulation early in the day, what is your typical, what does Matt Walker do to
get this light stimulation? - I am no poster child, but usually I will, if I'm working out I usually work out most days. And I shopped around and I found a gym that has huge amounts of window
exposure facing to the East. This is going to sound
so ridiculous you know, Matt Walker chooses a gym on the basis. - I love it
- Of the solar impact so he cannot you know
correct his circadian. - There are a lot of
criteria for selecting gyms, this one is actually
grounded in physiology, and biology and so. - And selfishness about my own sleep. - No it's great. So you get the your exercise and your light stimulation simultaneously? - That's right, yep, yeah. - And so you're stacking
cues for wakefulness early in the day. - Exactly, so both exercise and daylight are wonderful cues for
circadian rhythm alignment, and also circadian rhythm reset each day. And so I will use both exercise, I mean, I'm neither a strong morning type or a strong evening type. And my preference to exercise is probably sometime in
the middle of the day, probably somewhere around
1pm sorry, not 1am. But I'm usually working
out probably around the sort of seven, sort of 45 8am time, that's usually when I'll start my workout. And there I will start with cardio spin bike facing a window. And luckily, for the most
part here in California, there's usually sunlight coming through. But it doesn't matter to me because just as you said, even when it's a cloudy day that Lux coming through of light, the intensity is splendid. So I would prefer to favor my exercise just because for efficiency too, I want to get also working on the day, I'll try to match my exercise more with my circadian light exposure than I would probably if I'm going to do I really want to crush a workout, or do I want to just, you know, make sure it's a good workout? I would prefer to work out,
you know, at a different time. But I like that because of the daylight. And we can speak about
exercise timing at some point, because there's a lot of
discussion around that, when is the right time
to exercise during sleep. And we can sort of bust
some myths there too. So I think you're spot
on with the suggestion, get some morning daylight, try to get that exposure, usually
at least 30 to 40 minutes, there was some great
work recently coming out in the occupational health domain, where they moved workers from offices that were just facing walls and you know, didn't have any exposure
to natural daylight. And then they did a time
period during that study where they actually were in
front of a window and working. And they measured their
sleep and their sleep time and their sleep efficiency
increased quite dramatically. I'm forgetting the numbers now but I think the increase
in total sleep time is well over 30 minutes. And the improvement in sleep
efficiency was five to 10%. You know, and if you're
batting an 80%, you know, sleep efficiency average, we're a bit concerned about that. But add 10% to that and now you're in you know, a great echelon of healthy sleepers. And all you did was just spend some time working in front of windows. - That's great and probably folks might want to consider spending a little less
time with sunglasses provided they can do that safely, you know, driving, etcetera. You're not alone with
your exercise behavior and facing East. So the one and only Tim
Ferriss told me recently that his morning routine nowadays consists of jumping rope while facing East to get the sunlight
stimulation of the eyes. And as Matt and I both know, it has to be of the eyes, right? These portals are the only way to convey to the rest
of the brain and body about the time of day and wakefulness. Along the lines of wakefulness, I have a number of
questions about caffeine. The dreaded and beloved
caffeine, I love caffeine, but I like it in relatively
restricted periods of time. So I'm a big fan of waking up and even though I wake up very groggy, allowing my natural wakefulness
signals to take hold, meaning I wake up very slowly, but I don't drink caffeine right away. I sort of delay caffeine
by a little while, usually 90 minutes to two hours. And that idea came to me on the basis of my understanding of how caffeine and the
adenosine receptor interact. I have a feeling you're going to pronounce adenosine differently than I do. - No, no, I will with that,
I will go with adenosine. - I've tried to go with your
skeletal instead skeletal and synapse and synapse. - Schedule and schedule.
- There we go. But to make it really simple for folks, how does caffeine work to
make us feel more alert? And does the timing in
which we ingest caffeine play an important role in whether or not it works
for us or against us? So maybe we just start with
how does caffeine work? Why is it that when I
drink mate or coffee, which are my preferred
sources of caffeine, do I feel a mental and physical lift? - Yeah so I'm going to suggest counter to what most people
would think, drink coffee. - Or mate, is mate okay also? - [Matthew] Yeah, yeah, yeah. - Whatever form you enjoy. - We'll come on to sort
of why I suggest that but when it comes to coffee, I would say the dose and
the timing makes the poison. So let's start with how caffeine works. Caffeine is in a class of drugs that we call the psychoactive stimulants. So it works through a
variety of mechanisms, one is a dopamine mechanism dopamine we often think of
as a reward chemical or, but dopamine is also very much an alerting neurochemical, as well. And caffeine has some
role it seems to play in increasing dopamine. But its principal mode
of action, we believe in terms of making me more alert and keeping me awake throughout the day is on the effects of adenosine. And to explain what adenosine is from the moment that you
and I woke up this morning, this chemical adenosine has
been building up in our brain. And the longer that we're awake, the more of that adenosine accumulates, - Is it mask, may I ask, is it accumulating in neurons in glia, or in the blood vessels? Where and is it also
accumulating in my body? Where is this adenosine coming from? And where is it accumulating? - Yeah, so the adenosine
here that we're talking about that is creating the sleep pressure is a central brain phenomenon. And it comes from the neurons
themselves combusting energy. And as they're combusting energy, one of the offshoots of that is this chemical adenosine. And so as we're awake throughout the day, and our brain is
metabolically very active, it's accumulating and
building up this adenosine. Now, the more adenosine that we have, the sleepier that we will feel. So it really is like a sleep
pressure is what we call it. Now, it's not a mechanical
pressure, don't worry, your head's not going to explode, it's a chemical pressure. And it's this weight of sleepiness that we feel gradually growing as we get into the evening. - May I just interrupt
you again to just ask do we know what the circuit
mechanism is for that? I mean, not to go too
far down the rabbit hole, but for the aficionados and for myself, we have brain mechanisms
like locus coeruleus that are release things
that our brain areas locus coeruleus is just
being a brain area, of course that release things that
proactively create wakefulness. So are those neurons shutting down as a consequence of
having too much adenosine? Or are there areas of the brain that promote sleepiness
that are getting activated? Because these, you can imagine both things working in parallel, one or the other would
accomplish the same endpoint? - Yeah and it's both. And so there are two main
receptors for adenosine the A1 receptor and the A2 receptor. And they have different modes
of activating brain cells or inactivating or decreasing
the likelihood of firing. And adenosine works in this
beautiful, elegant way, where it will inhibit and shut down the wake promoting areas of the brain whilst also increasing
and dialing up the volume on sleep activating, sleep promoting range. - Biology is so beautiful. - [Matthew] Oh it's fantastic. - There's a push pull, I mean, and we could
have a larger discussion at some point about that, everything seeing dark
edges seeing light edges. Our ability to smell or
to sense pressure on this, everything's a push pull in Biology. - Oh it's great, yeah, yep. - So this is another example
where as I am awake longer, adenosine is released in the brain. And my wakefulness areas
are being actively shut down by that adenosine and my sleepiness brain
areas, so to speak, are being promoted to be
more active, is that correct? - That's right and it's a
very progressive process. It's not like a step function, where and sometimes that happens occasionally, but it's usually because you've
been sort of driving through and as we'll come on to
have caffeine in the system, and then all of a sudden
you just hit a wall and it just, you know engulfs you and you go from zero to
the one of sleepiness within a short period of time. - What explains the fatigue
after a hard conversation? The desire to go to sleep or desire to go to sleep
during a hard conversation? - That's an interesting one. I think it's usually just based on personality type interactions. And for the most part. - Not that I've ever
experienced that before. - No people with you
don't, but with me, they. - Oh no, no, I've
experienced the desired to some conversations, I'm
halfway through them and I feel like I want to take a nap. - Yeah.
- Right. - And I would love to look at you know, people's sleep history. We've sort of seen that
time and time again, but and then it could be,
you know, with folks like me, people just lose the will to live within about five minutes
of speaking with me, so. - Not true, they hear
that sleep is important. [cross talking] - Unrelated.
- [Andrew] That's awesome. - And that's flattery, that's great. But so the way that then caffeine
comes into this equation, as they're saying, it's usually
a kind of a linear process. Or maybe it's probably
closer to an exponential in terms of your subjective
feeling of sleepiness. And we haven't really been
able to measure that in humans, because normally, we it's
hard to actually, you know, stick something into the
brain and be, you know, sucking, siphoning off stuff
every couple of minutes, as you could do in animal studies. And keep asking people
every couple of minutes, how sleepy do you feel, how sleepy? And track to see if there's
a linear rise in, you know, adenosine, which then creates an exponential rise in
subjective sleepiness or what the dynamics are, but I'm kind of nerding out. Caffeine comes into play here, because caffeine comes into your system and it latches on to those
welcome sights of adenosine the adenosine receptors. But what it doesn't do is latch on to them and activate them. Because if it was doing that, then it would, you know, in lots of ways it would dial up more sort of sleepiness. It does the opposite. The way that caffeine works is that it comes in, competes
with quite sharp elbows with adenosine competitively
forces them out of the way, hijacks that receptor by latching onto it, but then just essentially blocks it. It doesn't inactivate the receptor, it doesn't activate the receptor, it functionally inactivates it in the sense that it takes it
out of the game for adenosine. So it's like someone you
know, coming into a room, and you're just about to
sit down on the chair, and caffeine comes in and
just pulls out the chair. And you're like, well, now
I've got nowhere to sit. And caffeine just keeps
pulling out the chairs from adenosine and adenosine even though it's at the same
concentration in your brain, your brain doesn't know that you've been awake for,
you know, 10 hours, 16 hours at that point when you've
downed a cup of coffee. Because all of that
adenosine that's still there can't communicate to the brain that you've been awake
for 16 hours because. - But the adenosine is
still in brain circulation. - Correct.
- So the real question is what happens when caffeine is dislodged from the adenosine receptor? - Unfortunate things happen. And that's what we call
the caffeine crash. Which is caffeine has a half life and it's metabolized and. - Do you recall what the half life is? - Yeah, the half life is somewhere between five to six hours. And the quarter life therefore is somewhere between 10 to 12 hours. It's variable, different people have different durations of its action, but for the average
adult five to six hours. That variation, we understand
it's down to a liver enzyme or a set of liver enzymes of the class that we call
the cytochrome P450 enzymes. And there are I think last
I delved into the data, which is pretty recently, there are two gene variants that will dictate the enzymatic speed with which the liver breaks down caffeine. And that's why you can have some people who are very sensitive to caffeine and other people who say, you know, it just doesn't affect me
really that much at all. - These are the people
that have a double espresso after a 9pm dinner and
can sleep just fine. - Well, and we'll come onto. - Well at least subjectively they think they are sleeping. - Subjectively, yeah,
and we should speak about that assumptive danger too. So then the caffeine is in the system and after some time period, it will be inactive in the system. So let's say that, you know, I've been awake for 12 hours now. And it's you know, 8pm and I'm feeling a bit tired, but I want to push through
and I want to keep working for another couple of hours, so I have a cup of coffee. All of a sudden I was feeling tired, but I don't feel like I've been
awake for 12 hours anymore. Because with the caffeine in the system, maybe only half of that adenosine is being communicated through
the receptor to my brain. 100% of the adenosine is still there, only half of it is allowed
to communicate to my brain. So now I think oh I haven't
been awake for 12 hours, I've just been awake for
six hours, I feel great. Then after a few hours, and the caffeine is starting
to come out of my system, not only am I hit with the
same levels of adenosine that I had before I'd
had the cup of coffee several hours ago, it's that plus, all of the adenosine that's been building up during the time that the caffeine has been in my system. - So sort of an avalanche of adenosine. - It is a tsunami wave, yeah
and that's the caffeine crash. - And it's interesting
because the caffeine crash at two o'clock in the afternoon
when you have work to do is a terrible thing. But what about the person, maybe this person is me in my 20s, who says, I'm going to
drink caffeine all day long. And then I want the crash. Because at nine or 10pm,
if I stop drinking caffeine at say, 6pm, and I crash, then I crash into a slumber,
a deep night of sleep. Is that sleep really as
deep as I think it is? Because given the half life of caffeine that you mentioned a few moments ago, I have to imagine that having some of that caffeine
circulating in my system might disrupt the depth of sleep, or somehow the architecture
of sleep in a way that even if I get eight, or who knows even 10 hours of sleep, it might not be as restorative
as I would like it to be. - Yeah, and that is the danger, just sort of that, you know, those people that you described who say, and I, a lot of them
will speak with me too say, look, I can have
two espressos with dinner and I fall asleep fine and I stay asleep. Because usually those
are the two phenotypes that we typically see
with too much caffeine. I just can't fall asleep
as easily as I want to, or I fall asleep, but I
just can't stay asleep. And caffeine can do both of
those things quite potently. - How late in the day do you
think is assuming somebody, translate this folks, if you
go to bed earlier or later, you have to shift the hours accordingly. But given somebody who typically gets into bed around 10:00, 10:30, and falls asleep around 11:00, 11:30. When would you recommend
they halt caffeine intake? And these are not strict prescriptives, but I think people do benefit from having some fairly clear guidelines of what might work for them. Would you say cut off caffeine,
by what time of the day? - I would usually say take your typical bedtime and count back sort of somewhere
between 10 to eight hours is probably getting a little bit close. But take back sort of 10
hours or eight hours of time, that's the time when you
should really stop, you know, using caffeine is the suggestion. And the reason is because for those people who even just keep
drinking up until you know, into the evening, you're right, that they can fall asleep fine, maybe they stay asleep, but the depth of their deep
sleep is not as deep anymore. And so there are two consequences. The first is that for me, and it can be up to by 30%, and for me to drop your deep sleep by 30%, I'd have to age you by
between 10 to 12 years, or you can just do it
every night to yourself with a couple of espressos. The second is that you then
wake up the next morning, and you think, well, I didn't
have problems falling asleep and I didn't have problems staying asleep, but I don't feel particularly
restored by my sleep. So now I'm reaching for
three or four cups of coffee the next morning, rather than just two or
three cups of coffee. And so goes this dependency cycle, that you then need your uppers to wake you up in the morning, And then sometimes people will
use alcohol in the evening to bring them down because
they're overly caffeinated and alcohol, and we can
speak about that, too, also has very deleterious
impacts on your sleep as well. So you're right that it's
not just the quantity of your sleep, or even
difficulties falling or staying asleep, it can also be deep sleep. But here again, I think, you know, I don't want to be frightening people. And I mentioned this before, I think one of the real problems that I or mistakes that I made, because I didn't you know, I'd never had much public
exposure before the book. And I was so saddened by you know, the disease and the suffering that I was seeing as a
consequence of a lack of sleep in our society. And the fact that it wasn't really being discussed very much. I sort of came out, you know,
a little bit headstrong, more than a little bit headstrong. And I think I was, you know,
perhaps too much gas pedal and too little, you
know, break as it were. And I don't think that's the right way to approach a health message
within the public sphere. And I've become much softer in how I think about these things. I have ideas about what the ideal world looks like for sleep. But I also realize that none of us live in this thing called the ideal world. - We certainly don't. - So, you know, I want to
be really mindful of that, and I think I've done a really bad job of being sort of too forthright, particularly for people who
struggle with sleep, you know, early on, when I would offer these sort of messages about sleep. I want to be, you know, I want to be theoretical
when it comes to the science, I want to be faithful to the science. But I also don't want to go out and scare the living
daylights out of people, particularly people who are
struggling with their sleep, 'cause it's probably only
going to make matters worse. So I've been beautifully schooled by learning how to be a slightly
better public communicator. I'm nowhere near of the
standing that you are, you are very elegant and
it's very intuitive to you. I'm still with training wheels, but I'm getting a little bit better. But I just want to say that when I'm speaking about caffeine, 'cause it sounds as though I'm very sort of overt about it. But I will come back to
why I say drink coffee. But I just want to make that point. - Yeah, well, I appreciate
you making that point. And I'm sure our listeners will too. I still will stand behind my statement, which is that what you've
done for the notion that sleep is vital for
all aspects of health and for performance, mental
and physical and wakefulness, the message and the
packaging it was contained in and is has been clearly
clearly net positive people needed to be cued to this. - Thank you.
- The I'll sleep when I'm dead mentality is one that I had, it's one that other people have. People in a huge number
of vital communities, not just your students, but also people that this the messaging that you provided and continue to provide has positively impacted the
first responder community, the medical community, there're still steps that need to be taken the military community, and of course, the civilian community. And so I think these adjustments about yeah, caffeine is okay, just restricted to the
early part of the day, if you can, most days, I mean, I think the law of averages. It's like the light viewing behavior I think it is critical to
view sunlight or natural, some other form of bright
light early in the day but if you miss a day, it's not that your whole system is going to dissolve
into a puddle of tears. That'll happen on the
second or the third day, no I'm kidding, you've
got a couple of days. Biology works in averages except with respect to accident or injury. A car accident is a car accident, right? You don't get to have three of those before the brain damage occurs if the accident's severe enough. But with sleep behavior, these homeostatic type
behaviors, or with food, one chocolate sundae, is it
going to kill you know? No. Every night? Yeah. It's going to make you
demented and kill you early. We know this. And so I think the middle ground is often a hard place to achieve. So I think you've done a phenomenal job. But I appreciate you raising these points. And I think it's clear that we all need to that we all can and should
do certain things better, including being gentle with
ourselves from time to time when we deviate from
these ideal circumstances. Along these lines, I do
want to talk about alcohol because I think caffeine and alcohol represent the the kind of two
opposite ends of the spectrum. Clearly there are other stimulants. There your Adderalls and
your high energy drinks that people use. But alcohol and caffeine are
the most commonly consumed stimulants and sedatives, depressants as they're sometimes called. So what happens when somebody has a glass? We always hear a glass or
two of wine in the evening or a cocktail after
dinner or before dinner, how does that impact their sleep? And then we'll be sure to circle back in terms of what is
reasonable ranges of behavior when it comes to avoiding alcohol or if it's age appropriate,
et cetera, enjoying alcohol? - Yeah, so alcohol, if we're thinking about classes of drugs, they're in a class of drugs
that we call the sedatives. And I think one of the first problems that people often mistake, alcohol is often used as a sleep aid for people who are struggling with sleep when things like over the
counter remedies, etcetera, or herbal remedies have just
not worked out for them. And alcohol, unfortunately,
is anything but a sleep aid. The first reason that most people use it is to try and help them fall asleep. - So and this process of this event that we call falling asleep, I have to imagine is a process. - It is a process.
- Like everything in biology, and that that process
involves in some way, as we talked about push
pull before turning off thinking, planning, et cetera, and turning on some sort
of relaxation mechanism. I have to imagine that these two things are knobs turning in opposite directions that gives us this outcome
we call falling asleep. Alcohol, it seems is
helpful for some people to turn off their thoughts
or their planning. Is that right? - Yes, it is. And so I think, you know, if we look at the pattern
of brain activity, if I were to place you
inside an MRI scanner, where we're looking at
the activity of your brain and watch you drifting off, some parts of your brain
will become less active. Other parts will become more active. And this is the push pull model. It's inhibition excitation. But alcohol is quite
different in that regard. Alcohol is because it's a sedative, what it's really doing is trying to essentially
knock out your cortex. It's sedating your cortex, and sedation is not sleep. But when we have a couple
of drinks in the evening, when we have a couple of nightcaps, we mistake sedation for sleep saying, well, I always when
I have a couple of whiskies or a couple of cocktails, it always helps me fall asleep faster. In truth, what's happening is that you're losing consciousness quicker, but you're not necessarily falling naturalistically asleep any quicker. So that's one of the first sort of things just to keep in mind. The second thing with alcohol is that it fragments your sleep. And we spoke about the
quality of your sleep being just as important as the quantity. And alcohol through a
variety of mechanisms, some of which are activation of that autonomic nervous system, that fight or flight branch
of the nervous system. Alcohol will actually have you waking up many more times throughout the night. So your sleep is far less continuous. Now, some of those awakenings will be of conscious
recollection the next day, you'll just remember waking up, many of them won't be. And so but yet, your
sleep will be littered with these sort of punctured awakenings throughout the night. And again, when you wake
up the next morning, you don't feel restored
by your sleep, you know, fragmented sleep or non continuous sleep in this alcohol induced way, is usually not good quality sleep, but you feel great on the next day. The third part of alcohol
in terms of an equation is that it's quite potent
at blocking your REM sleep, your rapid eye movement sleep. And REM sleep is critical for a variety of cognitive functions. Some aspects of learning and memory it seems to be critical for aspects of emotional
and mental health. - You've described it before as a sort of self generated therapy that occurs while we sleep. - Yeah, it's overnight therapy, you know, it's emotional first aid. - Certainly people that
don't get enough sleep are very easy to derail emotionally. Not that one would want
to do that to people, but we all sort of fall apart emotionally. I always think of it as almost like our skin sensitivity can be heightened. - Yes, absolutely.
- When we are sleep deprived. Our emotional sensitivity is such that when we're sleep deprived, such that it takes a much
finer grain of sandpaper to create that kind of
friction, things bother us. - [Matthew] Threshold to trigger. - Even online comments bother
us when we're sleep deprived. and never when we're well rested. - I would love to say
that I never look at them, except I look at. - Well actually, here I. - [Matthew] Maybe every one of them. - Here I will editorialize because the notion of
not looking at comments is unreasonable to ask of any academic, because academics we are all trained to look at our teaching evaluations. And just like with online
comments to ignore 20% of them, no, I'm kidding. We look at them all in any event. So in terms of translating
this to behavior, I'm not, I don't
particularly enjoy alcohol, I guess I might be
fortunate in that sense. But I also have never really experienced the pleasure of drinking alcohol. I sometimes like the taste of a drink, but I never like the sensation. So that's, I don't have a
lot of familiarity with this, but many people do, and I understand that. So let's say somebody enjoys
a glass of wine or two with dinner and they eat dinner at 7pm. Is that likely to disrupt
their sleep at all? Let's just sort of, let's make this a series of gradations. - And the answer is yes. I think once they just looked
at a single glass of wine in the evening with dinner, and I would be untruthful
if I didn't just simply say it has an effect. And we can measure that in terms of. - Less REM sleep. - Less REM sleep and one of the fascinating studies I can't remember what dose I
think they got them close to a standard illegal blood alcohol level, so maybe they were a little bit tipsy. And yes, you see all of the
changes that we just described, they sort of lose
consciousness more quickly, they have fragmented sleep, and they have a significant
reduction in REM sleep. But what was also interesting because REM sleep, as
we spoke about before, is a time when some hormonal systems are essentially recharged and refreshed growth hormone being one of them, there was well over a 50% five zero drop in their growth hormone release during alcohol laced sleep at night. - And growth hormone is
so vital for metabolism and repair of tissues. - Yeah, it's not just for kids. - [Andrew] Keeping body fat low. - This is essential in adults. - It's essential, along those lines, I just want to highlight the fact that this information that you're sharing that growth hormone is released is strongly tethered to the presence of healthy amounts of REM
sleep is interesting to me, because I always thought the
growth hormone was released in the early part of the night. - Well, it is released
across both of those, but across the different stages, but what we also know is that
when you disrupt REM sleep, there are those growth
hormone consequences. So it's not an exclusive system just like with testosterone, we can see changes
throughout non REM sleep, but if you ask when are
the peak release rates of testosterone, it's right
before we go into REM sleep, and then during REM sleep. - And of course,
testosterone being important, both for males and females. - For men and women, yeah. - Right, for libido and
tissue repair and well being. Nobody, regardless of
chromosomal, hormonal, or any other background wants to have their normal levels of testosterone reduced acutely, that's just a bad it equates to a terrible set of psychological and physical symptoms. - Yeah, and the mortality risk that's associated with low testosterone is non trivial.
- Prostate cancer. - Right, exactly, you know. So coming back to just
the point on REM sleep that you mentioned regarding
emotional instability, and we see that that's one of the things one of the most reliable
signatures of just insufficient sleep doesn't
have to be sleep deprivation. What we've discovered
over the past 20 years here at The Sleep Center, is that there is no major
psychiatric disorder that we can find in which sleep is normal. And so I think that firstly told us there is a very intimate association between your emotional mental
health and your sleep health. But when it also comes to REM sleep, I think what's fascinating is that it's not just about your emotional health, it's not just about your hormonal health we've also been seeing other
aspects of you know, cognition. But then there was a report, I think it could have
been about two years ago, out of Harvard, I think it
was Beth Clements group. They found that, and they replicated it in two
different large populations. If you look at the contribution of different sleep
stages to your lifespan, REM sleep was the strongest
predictor of your longevity. And it was a linear relationship. It wasn't it sort of one of these U shaped or J shaped curves that we
often see with total sleep, and mortality risk, it really was linear. That the less and less REM
sleep that you were getting the higher and higher
your probability of death. And then they did. - Was that death due to
natural causes or accident? 'Cause I can imagine if you're
not getting enough REM sleep, you're more likely to
drive off the freeway, step off a cliff. - I think it was all cause mortal. - You just make bad
decisions about anything in love relationships, which
can also be life threatening. - Yeah, I've tried to lean into that and claim that with those
bad relationship situations, oh, I just didn't have
enough REM sleep last night. - Blame it on the sleep. - [Matthew] My darling you know. - The REM sleep difference. - And, but she's far wiser than I thought. But, so they did this great
machine learning analysis and I may get these numbers backwards. But I think for every 5%
reduction in REM sleep, there was a 13% associated
increased risk of mortality. And I could have, I'll
have to go back and check. But to me, and in the
machine learning algorithm, what they ultimately spat out was that of all of the sleep stages, REM sleep is the most predictive of your longevity of your lifespan. So we often, I hear people saying, how can I get more deep sleep? Or they sometimes say how can I get more dream sleep? And my answer is a question. Why do you want to get more of that? And they'll say, well,
isn't that the good stuff? And I'll say, well, actually
all stages have good sleep. - It's all the good stuff. Well, it's like the exercise question and it took decades, for people to understand
that moving around for about 150, probably 180 minutes a week at doing endurance type work,
zone two cardio type work, it is correlated with living longer, feeling better, less diabetes, etcetera. There's really no way around it. I mean, you can ingest Metformin
until the cows come home, you can take NMN, all of which I think have
their place in certain contexts I'm a big fan of the work
surrounding all those protocols. - Yeah likewise.
- But without getting proper amounts of movement,
meaning sufficient numbers, it doesn't matter how many
12 minute exercise regimes you follow per week, you
need that threshold level. And it sounds like the
same is true of REM sleep and total amount of sleep. There's just you pay the piper somehow. - Yeah, the return on investment
I mean, to flip the coin, the return on investment
is astronomical, you know, I think of sleep it is the
tide that moves, you know, that raises all of those health boats. - And the most fundamental layer of mental and physical health. Whenever people ask me, even
though I'm not a physician, they'll ask me, you know, what should I take or what should I do? The first question is
always, how's your sleep? - Great, I love it. - Meaning how well do
you sleep every night and how long do you sleep? And I always recommend your book, I always recommend your podcast, you know, the podcasts you've been
a guest on, etcetera. Who knows, maybe you'll even
release your own podcast at some point soon and keep because I do think people need
to hear from you more often. One thing I don't want to
return to the notion of public health discourse too much. But I do want to say one
issue with books in general, is that they can be revised, but it's more or less a
one and done kind of thing until the next book comes out. - Yeah, yeah
- One thing I like about the podcast format is that updates can be provided regularly. Corrections and updates
as new data come out. And so that's a wonderful
aspect to this format. And hopefully the format
that you'll be embracing, I think the world needs
to hear more from you more often, about sleep, and
its various contours, not less. And so I do have a question
about drinking alcohol. Not that we want to promote day drinking, but let's say that the
one or two glasses of wine or cocktail is consumed with lunch, something that isn't
traditionally done nowadays, or in a late afternoon
happy hour type cocktail. And then one is going to sleep
seven or eight hours later, do you think that that will improve or somehow mitigate the effects of alcohol? Or if you have a drink, are you are you basically
screwed for the next 24 hours? - No, I think there's going to
be a time window dependency. Now, I don't know of anyone
who has essentially done what you and I would like, which is the time separation
dose dependent curve, where okay, you drink
at 10am, then or 11, 12 one, two, three, four, five all the way up to you know, 10pm and estimate, what is the blast radius? And is it linear? Or is it nonlinear? Is it such that only when you
drink in the last four hours? Do you just hit this exponential
and it's bad, bad bad? Or is there some other curve that we could imagine there
will be many possibilities. But certainly what we know
is that the less alcohol and the less and more specifically
the metabolic byproducts, aldehydes and ketones, they're the sort of the nefarious players. - And not the ketones that
people are all excited about the other ketones, [cross talking] the chemists know what we're referring to. - But this is not about ketogenesis, please don't think that. - This is not about ketogenesis, there are ketone bodies, and that are released
after ingesting alcohol that are not of the positive sort that a ketogenic diet might promote. - Right, so I think in terms
of that alcohol profile, we certainly know that, you know, as you're heading into the evening hours, once again, timing and
dose make the poison. But I think it's also
important, once again, from that public message
standpoint, and thank you, I think I am leaning into the sort of the podcast
consideration arena, at some point, but I don't want to be
puritanical here, you know, I'm just a scientist, and I'm not here to
tell anyone how to live. All I'm trying to do is empower people with some of the scientific
literature regarding sleep. And then you can make
whatever informed choices that you want. Now, unlike you, it turns
out, I'm not a big drinker. It's just because I've
never liked the taste. And I'm surprised that
they haven't taken away my British passport because
I don't like lager or beer. But I also want to say
that life is to be lived to a certain degree, it's all
about checks and balances. So, you know, if I go out and you know, I have an ice cream sundae,
I'm not big on those either, but, you know, sure, I
know that my you know, blood glucose is not going to be ideal for another 12 hours maybe. That's just the price you pay for having some kind of relaxed, fun life. I don't want to look back on life and think, gosh, you know, I
lived until I was, you know, 111 and it was utterly miserable you know. - Right.
- So, but it's all about some kind of a balance. And my job is not to tell
people a prescription for life, it's just to offer some
scientific information. - No, I think you're doing
a terrific job of that. People are I always say we
have all these neural circuits and if it's working properly, we all have a circuit that allows us to skip over information
or as we wish, right, if the circuits between
your brain and your thumbs are working you can slide right along you can drop to the next
content however you like. I would like to ask
about marijuana and CBD. This is a discussion that
I think five years ago would have ventured into
the realm of illegal but now in many places not all medical marijuana is approved or is legal. And certainly it's in widespread use. Certainly not recommending people do it. I have my own thoughts
about marijuana CBD. I've been fortunate, I suppose that I don't particularly
like marijuana or CBD. I don't even know if I've ever tried CBD. First of all, does marijuana
disrupt the depth of sleep, the architecture of sleep? And if so, as with alcohol and caffeine does when you ingest it or when it's in your bloodstream does, relative to when you go to sleep, does that play an important role? So does marijuana disrupt sleep? - Yeah, it does. And there's a pretty
good amount of data on so we can break sort of cannabis down into two of its key ingredients. We've got THC tetrahydrocannabinol,
and we've got CBD and CBD is sort of the less psychotic what we think of as the non
psychoactive components. In other words, when you
take CBD, you don't get high. If you take THC, you can get high. That's the psychoactive
part of the equation. - Are both considered sedatives
in the technical sense? - No, they're not. Neither of them have that class right now. THC can, seems to speed up the time with which you fall asleep. But again, if you look at the
electrical brainwave signature of you're falling asleep
with and without that THC, it's not going to be an ideal fit. So you could argue it's non natural, but many people use THC for that fact, because they find it
difficult to fall asleep. And it can speed the onset of at least non consciousness, I guess is the best way of describing it. But there are problems with THC. And they are twofold. The first is that it too, but through different mechanisms
seems to block REM sleep. And that's why a lot of
people when they're using will tell me look, you know, I definitely, I was dreaming. Or I don't remember, you
know many of my dreams. And then when they stop using THC, let's say I was having, you
know, just crazy, crazy dreams and the reason is because
there is a rebound mechanism. REM sleep is very clever. And alcohol is the same way in this sense, it's the same homeostatic mechanism. Some people will tell me, look, if I have a bit
of a wild Friday night with some alcohol, you know, maybe I'll sleep late
into the next morning. And I'll just have these
really intense dreams. So and I thought I wasn't
having any REM sleep, well, the way it works is that it's during in the middle
of the night, really, when alcohol blocks your REM sleep. And your brain is smart it understands how much REM
sleep you should have had, how much REM sleep you have not because the alcohol
has been in the system. And finally, in those early morning hours, when you're getting through
to sort of, you know, [cross talking] six, seven, 8:00am all of a sudden, your brain not only goes back to having the same amount
of REM it would have had, it does that plus it tries to get back all of the REM sleep that it's lost. Does it get back all of the REM sleep? No, it doesn't. It never gets back all of
the REM sleep, but it tries. And so you have these really
intense periods of REM sleep. Hence you have really
intense bizarre dreams. And that's what happens also with THC, you build up this pressure for REM sleep, this debt for REM sleep, will you ever pay it back? Doesn't seem as though you get back everything that you lost, but will you get back some of it? Yes, the brain will start to devour more because it's been starved
of REM sleep for so long. But one of the bigger problems with THC that we worry about is
withdrawal dependency. So as you start to use THC for sleep, there can be a dependency tolerance. So you start to need more to
get the same sleep benefit. And when you stop using, you usually get a very
severe rebound insomnia. And in fact, it's so potent that it's typically part of the clinical withdrawal profile from THC from cannabis. - And there's anxiety withdrawal. I you know, I don't ask anybody
to change their behavior, we just as you said, we
try and inform people about what the science says and let them make choices for themselves. People who are regular pot smokers, if you many of will insist
they're not addicted, and maybe indeed they don't
actually follow the profile of classical addiction, I don't know. I'm guessing some do, some don't. But if you ask them well, what if I took away all
marijuana consumption for, I don't know, two weeks? That thought scares many of them. And many of them will experience intense anxiety without marijuana, which speaks to perhaps not addiction, but a certain kind of dependency. And again, you know, I
know many pot smokers, some of whom have jobs that are quite high
performing and they manage. - Here in Berkeley, I
don't know any of those. - Yeah, none of those, right. What about CBD? I mean, we hear so much about CBD, I've been a little concerned
about the fact that the analysis of a lot of
CBD supplements out there has confirmed that much
like with melatonin, the levels that are
reported on the labels, in no way shape, or form, match the levels that
are actually contained in the various supplements. Sometimes the levels are much higher than they're reported on the labels. Other times, it's much lower. What does ingesting CBD do to the architecture and quality of sleep? - Right now, I don't
think we have enough data to make some kind of, you know,
meaningful sense out of it. I think the picture that
is emerging, however, is probably the following. Firstly, CBD does not
seem to be detrimental in the same ways that THC is. So we can start by saying does it create you know,
potential problems, not of the nature necessarily
that we see with THC. But the devil is a
little bit in the details from the data that we do have and it comes on to your
valid point of purity. At low dose, CBD can seem
to be wake promoting. So in lower doses, let see sort of five or 10 milligrams and trying to remember some of the studies off the top of my head, there it actually may enhance wakefulness and cause problems with sleep. It's only once you get
into the higher dose range, that there seem to have
been some, you know, increases sorry, increases in sleepiness, or sort of sedation like, increases. And that's usually I think,
above about 25 milligrams, as best I can recall from the data. And then when we look in animal models, you typically see the
same type of profile too. So then the question becomes and now again, you just don't
know about, you know, purity. It's very difficult,
although I think, and again, I'm not a user, not necessarily because I you know, have anything against it. It's just that's not, you know,
necessarily my cup of tea. There are some firms that are now doing third party independent laboratory tests. I don't know how gamed that is, so I've got no sense of it. - I think some supplement companies are quite honest and accurate about the amounts of various substances that are in their
products and some are not. And I think there's just a huge range. I think the FDA is starting
to explore CBD there I certainly I saw some grant announcements to explore the function of CBD. Most of the work on CBD is
being done by the general public adjusting it and seeing how they feel. I gave it to my dog who was had some dementia related
sleep disturbances, and it actually created
a heightened wakefulness it completely screwed up his sleep. - Okay, it sounds as
though it just wasn't. - He's a bulldog. So if he's going to get access
to sleep, he's going to take it. - Okay.
- Really messed him up, took him took it away, he did better. But you know, that's a canine, so. - Right, and it could have been, you know, sort of dose related too. - Or binders or other things
that are in there, sure. - Correct, yeah and we, but right now, if we were to, and I'm not making the statement, I don't think anyone can
make the statement now. But if it ends up being that CBD is potentially beneficial for sleep, how can we reconcile that mechanistically? And I think there are, to me, at least, there are at least three
candidate mechanisms that I've been exploring
and thinking about. The first is that it's thermo regulatory. And what we found in some animal models is that CBD will create
a profile of hypothermia. In other words, it cools the body the core body temperature down. And that's something that
we know is good for sleep. The second is that it's an anxyolitic, that it can reduce anxiety. And that data is actually quite strong, even with some functional imaging work that's been coming out recently showing that one epicenter of
emotion called the amygdala deep within the brain is
quietened down with CBD. So I think that's at least a
second non mutually exclusive. - That's great, that's conducive. - You know, possibility. I think the third is some recent data that's come out that was suggesting that CBD can alter the
signaling of adenosine. So it doesn't necessarily mean that you produce more adenosine, but what it can do is perhaps modulate the sensitivity perhaps of the brain, so that the weight of that same adenosine is weightier in its brain signal, and therefore it creates this
stronger pressure for sleep. So I think these are all
tentative mechanisms. I think any one of them is viable, I think all three are viable together. But right now I think, does that sort of help think through the tapestry of THC and CBD? - Yeah very much so and
actually, it's a perfect segue from we've talked about
caffeine, alcohol, THC and CBD as sort of, we framed them anyway, as things that done in moderation at the appropriate times, are probably okay for most people. Certainly not for everybody, there will be differences in sensitivity. But that done at the incorrect times, and certainly in the incorrect amounts will greatly disrupt this vital
stage of life we call sleep. CBD, it seems, represents a kind of bridge to the topic I'd like to talk about next, which is things that
promotes more healthy sleep, or somehow contribute to
enhancing the architecture and quality of sleep. So I'd love to chat for a moment about the kind of grand, the original I should say that not the granddaddy but the
OG of sleep supplementation, which is melatonin. The so called hormone of darkness that's inhibited by light, etcetera. Frame for us, melatonin in the context of its
naturally occurring form. And then I'd like to talk
about melatonin the supplement because in my experience,
anytime I say the word melatonin, people think about the
supplement melatonin, which in itself is an
interesting phenomenon that people are so cued to its role as something you take, we often forget that this is something that we make endogenously. I'd love for you to comment in particular on even though without
necessarily getting into its precise nanograms
per deciliter values, what are the typical amounts of melatonin that we release each night? And then I'd like to compare that to what is contained in
say a three milligram or six milligram tablet that
one might buy at the pharmacy. - Right, yeah.
- So I go to sleep at night, has melatonin already kicked in before I shut my eyes
and lay down my head? - Usually, yes, if your system is working in the correct way, as dusk is starting to happen, so let's say that you look
at hunter gatherer tribes who aren't touched by electricity, and so that's sort of the
puritanical state par excellence when it comes to electric light influence. And usually, it's as dusk is approaching, that's when melatonin will start to rise. And so when you lose the brake pedal of light coming through the eyes, that normally acts like a hard brake pedal that stamps down and prevents the release and production of melatonin. As that light brake pedal
starts to fade with dusk, then we ease off the brake pedal and melatonin the spigot
of melatonin is opened up, and melatonin starts getting released. And usually we'll see this
rising peak of melatonin sometime, usually an hour,
two hours later or around and it varies from different people around the time of sleep itself. But it's already been on
the march for some hours before you actually hit sleep itself. - Interesting, and I was always taught and I'm assuming it's still true that the only source of
melatonin in the brain and body is the pineal gland. Is that still true? - Yeah, it seems to be
from best that we can tell the pineal gland sort of
meaning pea like sort of shape. It's actually I think usually
people say it's pea like, I think if you look at the
Latin derivative, it's more, I think it's derived
from pine cone, not pea because in fact, if
you look at the pineal, it is more pine cone shaped and so is aptly named. - Any human brain I've ever dissected or I confess I've dissected a lot 'cause I teach neuroanatomy
and have for years. I love looking at the pineal it's the one structure in the brain that's not on both sides. It's usually pretty easy to find. And it's a pretty good size. It looks like a, it looks like a pea. And it's sitting right there. And it's remarkable that
it releases this hormone. Sort of probably our entire
lifespan is inhibited by light. So our pineal starts to release this into the general circulation. I have to imagine we
have melatonin receptors in the brain and body. - It's correct, so yep, essentially, your brain has a central
Master 24 hour clock called the super charismatic nucleus that keeps internal time. Now it's not a precise clock
if left to its own devices, nothing that a Swiss clock
maker would be proud of. It runs a little bit long and laggy. - It's like an American clock. There are a couple of good
American watches by the way, Hamilton's are very nice, but. - It's very much like a bug. - We're not famous for our timekeeping or our punctuality for that
matter, but the Swiss are. - It's very it's not quite Swiss, like it's more Berkeley like,
which is very relaxed. Oh you know what whatever. So in most adults, the
average adult, I should say, your biological clock normally
runs a little bit long, it's about 24 hours and 30 minutes, I think was the last calculation. But the reason that we don't
keep drifting forward in time and kind of running consistently, you know, more and later and later, 30 minutes by 30 minutes
by 30 minutes each day, is because your central brain clock is regulated by external
things such as daylight and temperature, as well
as food and activity. All of these are essentially
different fingers that come along and on the
wristwatch of the 24 hour clock will pull the dial out
and reset it each day to precisely 24 hours. And I make that point because
it knows 24 hour time, but it needs to tell the rest
of the brain and the body, the 24 hour time as well. And one of the ways that it does this is by communicating a chemical signal of 24 hour nurse of light and day using this hormone, melatonin. And when it is at low levels, or it's non existent, it's communicating the
message it's daytime, and for us diurnal species,
it says it's time to be awake. Yet, at nighttime, when dusk approaches and the
break comes off melatonin and we start to release it, then it signals to the rest
of the brain and the body, look, it's dusk and it's nighttime. And for us diurnal species,
it's time to think about sleep. So melatonin essentially
tells the brain and the body when it's day and when it's night, and with that when it's time to sleep when it's time to wake. And therefore, that's why melatonin helps with the timing of the onset of sleep. But it doesn't really help with the generation of sleep itself. And this is why we'll come on to what those studies of
supplementation have taught us. - So it tells the rest
of my brain and body, it's time to go to sleep. It perhaps even aids with
the transition to sleep but it's not going to for instance, ensure the overall structure of sleep or it's not the conductor that's guiding the sleep
orchestra so to speak throughout the entire night. - Yeah, it's.
- It's more like the people that essentially
take you to your seat and sit you down and
give you your program. - Right, exactly yeah,
sort of the the fall, less sophisticated analogy
I have is, you know, melatonin is like the starting official at the 100 meter race in the Olympics. - That's a better analogy, yeah. - It calls all of the
sleep racers to the line and it begins the great sleep race. - Yeah, better analogy by the way. - [Matthew] It doesn't help
dissipate, no, no, no, no. - Coming from the sleep
researcher of all people. - But it doesn't participate
in the race itself. That's a whole different
set of brain chemicals and brain regions. Which then brings us on to perhaps the question of supplementation, which is, is it helpful for my sleep? Will I sleep longer? Will I sleep better? And if I am, what dosage
should I be taking? Sadly, the evidence in healthy adults who are not older age suggests that melatonin is not really
particularly helpful as a sleep aid. I think there's a recent meta analysis that demonstrated when it looked at all of the
different sleep parameters, melatonin, and a meta analysis for those not knowing what that is, it's a scientific sort
of method that we use where we gather all the individual studies and we put them in a big bucket and we kind of do this kind of statistical fancy sleight of hand. And we try to come up with a big picture of what all of those
individuals studies tell us. And what that meta
analysis told us is that melatonin will only increase
total amount of sleep by 3.9 minutes, on average. - Minutes?
- [Matthew] Minutes. - Not even percent. - And it will only increase
your sleep efficiency by 2.2%. So it really. - This is as they say, in
certain parts of California, that's weak sauce, that's
a weak sauce effect. - The sauce is not strong, the force is not strong in this one, when it comes to a tool
that in healthy people who are not of older age, it doesn't seem to be
especially beneficial. Now, you know, results can vary. Everyone is different, of course. So we're talking about the average, the so called average human adult here. - Well, melatonin, in
defense of what you're saying and also I should mention, I have a colleague at
Stanford, Jamie Seitzer. - Oh, wonderful, genius. - Chuck Seitzer's lab at Harvard Med where he also trained
terrific sleep researcher and I asked him about melatonin and he essentially said the
same thing that you just said which is very little if any evidence that it can improve sleep and yet it's probably the
most commonly consumed so called sleep aid. - Hundreds of million dollars industry. - Yeah, so either massive placebo effect or it's operating through
some other mechanism related to quelling anxiety perhaps? - Well, yeah, that's essentially
interesting, you know, there are some studies where you do see some, you know, effects. Now, again, when you do the
grand average of all studies, it just doesn't seem to have an effect. But let's assume that for some people, it does have an effect let's not again be sort of
completely dismissive of that, how could it have that effect? One of the reasons that I've become a little
bit more bullish on melatonin from a sleep perspective and then melatonin more generally for a, maybe you can speak about this too, as a counter measure when you're undergoing insufficient sleep. There are two different routes there. The first reason that I think it could have a sleep
benefit for some people is not because it helps in
the generation of sleep, we know that it doesn't, it's because it too seems to
drop core body temperature. - There it is, temperature again. I'm fascinated these days, more and more by temperature, as maybe not just a
reflection of brain state and wakefulness and in sleep, but actually a lever
that is quite powerful. - I think it's both. - And with all the interest
in ice baths and hot showers and saunas and stuff, something that we will
definitely touch on. Temperature variation is so key. So if melatonin is
dropping body temperature by a degree or so something
that you've said before can help induce a sleepy state. Maybe that's what's allowing
people to get in to sleep. - I think that's one possibility. I don't think melatonin by itself will drop it by it sort
of, you know, a degree, certainly not a degree Celsius. And for order in us to fall asleep, and then stay asleep across the night, we do need to drop our
core body temperature by about one degree Celsius, or about two to three degrees Fahrenheit. And that's why it's always easier to fall asleep in a room
that's too cold than too hot. I think that that's one potential avenue that we are considering
thinking more deeply about when it comes to melatonin. And then the other is
melatonin as an antioxidant. But let me table that for now. 'Cause I'll just get us sidetracked. That's what we know so far about melatonin in terms of its supplementation
benefit or lack thereof. Two final points that I shouldn't forget, one is the only population
where we typically see some benefit, and it often is prescribed is in older adults, because as we. - Older meaning 60 and older? - Yeah, 60, 65 and older because as we get older, you can typically have what's called calcification of the pineal gland. Which means that that gland
that's releasing melatonin doesn't work as well anymore. As a consequence, they tend to
have a flatter overall curve of melatonin release throughout the night. It's not this beautiful, lovely peak, and this bullhorn message of its darkness, please get to sleep. That's why older adults can
have problems falling asleep or staying asleep. It's not the only reason by
any stretch of the imagination. But it's one of the reasons and it's why melatonin
supplementation in those cohorts, older adults, and especially
older adults with insomnia, people have thought about that as maybe an appropriate use case. - Well, along those lines, if we were to compare dosages, I don't, do we know how much melatonin is typically released into
the bloodstream per night? And can we use that as a
kind of a rule of thumb by which to compare the typical amount that someone would supplement? Typically, the supplements
for melatonin that I see in the pharmacy and elsewhere online range anywhere from one milligram to 12, or even 20 milligrams. My guess is that a normal
night's release of melatonin typical for somebody
in their 20s, 30s, 40s would be far lower than
that, am I correct or wrong? - Yeah, it's many magnitudes lower. And this is one of the problems
is that I see that too. I see, you know, typical
doses are, you know, five milligrams or 10 milligrams and of course, you know, if
you're a supplement company, you know, putting 10 milligrams
versus five milligrams, if that's what you're actually doing, which we'll speak about purity as well. You know, it's kind of
like the super gulp size, nobody wants to lower price, they just want you to you know, we'll just give you
more for the same price. And that's how we'll compete. So it's been this escalating arms race of melatonin concentration, and it really does not look meaningful for, you know, for sleep in any way. What we've actually found is that the optimal doses for where you do get sleep benefits in the populations that we've looked at, are somewhere between 0.1 and
0.3 milligrams of melatonin. In other words, the
typical doses are usually 10 times, 20 times maybe more than what your body
would naturally expect. And this is what we call a
supra physiological dose. In other words, it's far above what is physiologically normal? You know, and to put that in context, imagine I said to you, I want you to eat 20
times as much food today. - I thought you're going to
use testosterone as example. You're going to take 300 times the normal amount of testosterone we know that would have
tons of deleterious effects it would be terrible. And yet you can do this. One thing that I'm concerned about about these super physiological
levels of melatonin is that many years ago,
actually, here at Berkeley, when I was a graduate student, we would inject animals which were seasonally breeding
animals with melatonin. And the consequence of
that was that their gonads, either their testes or
ovaries would shrink, many hundred fold or more. In other words, they would go from having nice healthy sized hamster testicles, what a hamster would consider
healthy size for a hamster and they would shrink to
the size of a grain of rice. So from like an almonds to a
grain size of a grain of rice. I had to see that only once for me to be very concerned about super physiological levels of melatonin. And I realized that melatonin
does different things in different species. We are not hamsters, we
are not seasonal breeders seasonally restricted breeders, there might be more breeding
during certain seasons, I don't know those data. But nonetheless, hormones are powerful. And sure there is an optimal, and sometimes we see that going slightly above endogenous
levels for certain hormones not always, can have beneficial effects. And sometimes it can
have detrimental effects. I'm just concerned
about taking high levels of a hormone that has effects
on the reproductive axis and that's one of the reasons
why I get very concerned when I see people really
getting aggressive about melatonin supplementation taking 100, 10, 500,
sometimes even 10,000 times the amount that we would normally release. That's my concern, although it's not nested in
any one specific human study. I just don't like to see, I certainly don't want to see other people and I don't want to
personally take a hormone that's known to be androgen
suppressive at high levels. Why would I take that? That's the question I ask myself. - I think it's a very,
you know, good point. And if you look at some of
the evidence around, you know, melatonins lethality if you
want to go to that extreme, for the most part, you
know, it's pretty safe. - You mean, you can take a
lot of it before you die? - Right, exactly yeah. - But I don't know that
that's the criteria. - That should be your yardstick for, because, you know, you
really need to think about your, you know, your health, not just whether this thing
is going to kill you or not as the decision matrix
through which you pop a pill. And it comes on to this
concern around melatonin because there was a study, I think it's one that you mentioned too where they looked at over, I think it was at least
over 20 different brands of melatonin supplements. And what they found is
that based on what it said, on the bottle versus what was
in the capsules themselves, it ranged from, I think it was 83% less than what it said on the bottle to 478% more than what
it said on the bottle. Now, if that's a 10
milligram, you know, pill, and it's 478% more than 10 milligrams, and we're already at 10 milligrams at many tens of times more than is a physiological rather than a supra physiological dose, we do need to be a bit thoughtful. - Yeah, remember those hamsters folks. Well, and I do appreciate the deep dive on melatonin because I think people need to understand that it's nuanced, it's
a matter of dosages, and timing, etcetera. And then it may have its place as you mentioned in older individuals. And I should mention
that I'm an avid consumer of supplements that I believe in for me and I have been for a very long time. So I'm by no means anti supplement. Some supplements I refuse
to take or avoid taking others I quite avidly take
and along those lines, I personally and I don't know what your thoughts on this are. But there are a few things that I've personally found beneficial. I love your thoughts on them. And I would love it if
you would tell me that everything I'm about
to refer to is placebo, that would be fine. So that's what we do, we're scientists we argue and then we remain friends
in as it goes away. So magnesium, there are
many forms of magnesium. Magnesium citrate is a as we know, is a terrific laxative. Magnesium malate seems, at
least from a few studies seems to relieve some of
delayed onset muscle soreness doesn't seem to create a kind of sedation. Two forms of magnesium that I'm aware of magnesium biglycinate and magnesium threonate. We believe based on the
data can more actively cross the blood brain barrier. So you put in your gut, but some of that needs
to go into your brain in order to have the sedative effect. What are your thoughts on
magnesium supplementation? Do you supplement with magnesium? And what studies would
you like to see done if they haven't been done already. - So I don't supplement with magnesium. But I do think threonate is interesting because of that higher capacity to cross the blood brain barrier and actually have a central
nervous system effect. And the reason that that interests me is because the sleep is
by the brain of the brain, and also for the brain,
as well as for the body. We just don't have a
particularly good set of studies that have targeted exclusively threonate. We do have lots of studies that have just looked at
magnesium in general for sleep. And overall, the data is uncompelling. - Interesting.
- And for a while, I was confused as to why, where did this come from this
kind of myth of magnesium? So I started looking
back into the literature and I've best traced it at
least as far as I can tell, to early studies showing that those who are deficient in magnesium also had sleep problems. They had other problems too, of course, but sleep problems were
one of that set of sequelae that came from having lower magnesium. And when they supplemented with magnesium and tried to restore those levels, some of those sleep problems dissipated. And then that seems to have gotten lost in sort of some game of sort of like whispers around the room and it's become translated into people who don't have sleep problems, who are healthy sleepers, and
who are healthy in general, and who have healthy
normal levels of magnesium, if they take more magnesium,
they will sleep better. And the data really, there is not good. Once again, the only study that I've seen where magnesium did have some efficacy was in a study with older adults, I think they were 60 to 80 years old, it may have been exclusively women, now I think about it and they also had insomnia. And in that population,
you did see some benefits. And my guess is that because it's an older community as well, they were probably deficient in magnesium. So they fit the former category of simply when you're
deficient, and you restore, you can help sleep sort
of return to normal. But if you are not deficient
and you're healthy, and you're not old and
you don't have insomnia, and you're supplementing thinking that it provides
sleep, right now, the data isn't supportive of that. But I just don't think we
have enough threonate data to actually speak about that, because it could just be a
blood brain barrier issue so far with the other forms. - So maybe some additional studies looking specifically at
threonate or bi-glycinate would be useful.
- I'd love to have. - Magnesium is involved in
so many cellular processes, you can imagine that this
effect, if it truly exists is, as we say, in science in the noise, meaning it's in the jitter of the data, but to isolate the real effect one needs to do some more refined studies. What are some things that
are of interest to you, if not things that you happen to take? These are not things
that I personally take mostly because I just haven't
experimented with them. valerian root is one, tart cherry and kiwi fruit. Tell me about Valerian root,
tart cherry and kiwi fruit. This is new to me. I have certainly heard of them. And tart cherry and Kiwi sounds delicious, but what's happening with
Valerian root tart cherry and kiwi and are we talking about
eating tart cherries and Kiwis and Valerian roots?
- Yes. - Or are talking about
taking them in pill form? - Usually it's supplements, but it's also both for tart
cherries and for kiwis. It's the actual, you
know, fruit themselves. Valerian often touted as
a beneficial sleep aid and lots of people swear by it too. But the evidence is
actually quite against that. - Oh really?
- Not that it makes your sleep worse, but of at least the seven good studies that I've been able to find, and typically these are of the nature of what we call a randomized
placebo crossover design. And I won't bore people
with what that means it's sort of one of the. - Good studies, solid studies. - Yeah, it's one of the sort
of gold standard methods that we have when we're
looking at intervention studies such as drugs studies. Five of the seven found no benefits of Valerian root on sleep. Then two out of the seven, the
data was just insufficient. I think it was a power issue where they just couldn't
make any strong conclusions. And then I think there
was the most recent study, I think looked at two
different doses of Valerian and I could have this wrong and they just failed to
find any effects once again, but the stunning part of
that paper, as I recall, they had this big table with all of the different sleep
metrics that they looked at. And there were well
over 25 different things that they tried to see
if valerian impacted. And none of them were significant. Which stuns me because from
statistical probabilities, we know, if you just randomly
perform 25 statistical tests, chances are probabilistically, you'll just get one significant
result by random chance. And even with random chance on their side, they still couldn't find
a benefit of Valerian, so. - So Valerian root might be
worse than nothing at all, if there is, so to speak. - I mean, again, placebo effect we can think about that too. And I would say that if you feel as though it's having a benefit for you, and with all of the caveats
that we have with supplements, things like melatonin purity,
concentration, et cetera, you know, maybe it's no harm no foul. But I'm not a you know, a medical doctor and I don't tell anyone about we have all of these disclaimers about not recommending such things. - And we'll include these, I mean, I always say, you
know, we're not physicians, we don't prescribe anything. We're scientists and professors
so we profess things. It's up to people to be
responsible for their own health. Not just to protect us
but to protect themselves. I do want to hear about
tart cherry and kiwi fruit. What's the story there? - Strange, isn't it? I was, you know, I'm kind
of a hard nosed scientist, and when people you know,
some years ago started saying, oh, tart cherries, it's
the thing or kiwi fruits, I was thinking, oh, my
goodness, the sounds a bit. - You've been in California
a little too long. - Yeah, I know, yeah, the
sun is softened me some. But I thought, look one of the things that we
have to do as scientists is be as open minded as possible. And I should not be so quick to dismiss. So I went to the literature just started reading as
much as I could about it. And there were three really good randomized placebo crossover
trials with tart cherries. And what they found was that in one study, it reduced the amount of time that you spent awake at
night by over an hour. And then the other two studies, one of them found that it
increased the amount of sleep that you've got by 34 minutes. The other it increased the
amount of sleep that you got by 84 minutes. Which you know, these are, and what's striking is that
they were independent studies, I think, meaning that they
were from independent groups, and these were, you know,
some of these guys, you know, and girl, I know pretty
well, and they are really. - You know and trust their work. - Right, I really trust their work too. - Were they ingesting actual tart cherries or they're drinking the
juice or in capsule form? - It was juice. So they in all three
studies, it was juice. Although you can I think as a supplement, you can buy it in a capsule, and we've got no idea whether that changes the benefit or not. What was also interesting in I think it was that last study where they got an increase
in sleep by 84 minutes, it also decreased a daytime
napping significantly. - That's one that I could
certainly make use of. I love my day time naps, but I'd love to skip them too. - Right and we can speak about naps and sort of the upside
and downside of that. Which then made me think
well, if that's the case, may be the net net
benefit on sleep overall, is no different. It's just that it decreases the amount of time that some people were taking to sleep during the day, and giving it back to the night. But that wasn't the case, 'cause if you added the
total amount of sleep that they were getting
without tart cherries, both naps and nightly sleep combined, still, when you took tart cherries, you still got a net some benefit, of total amount of sleep. So you know, so far, when it comes to supplements, and those types of studies,
they're good studies, and the data looks interesting. But as a drug itself, you know, if this was clinical drug, you know, three studies that are
somewhat small in nature and have some positive benefit that's what we would call preliminary data of maybe a chin scratching
kind so keep this in context. - Yeah, and depending on
the margins for safety, one might think, well, given that it's a tart cherry as opposed to some pharmaceutical you need a prescription for then, you know, some
people their threshold to experiment with
supplements is quite low, some people their threshold is quite high. I feel like you know,
there are two categories, or at least two categories
of folks out there. People who hear oh, tart
cherry can improve sleep, and we'll run out and try it. And people who hear
well, that sounds crazy. Why would I do that? But of course, we have to remind people that tart cherry isn't really
what we're talking about, presumably if this is a real effect, and sounds like it might be that there's a compound in tart cherries. - That's right.
- That if we were to call it, whatever, whatever five
alpha six, you know, some molecule, if we refer
to it by its technical name, then people would say, oh, that sounds like a very
interesting technical way to approaches sleep but doesn't sound very natural. So both groups are a little bit misguided in the sense that people who think that everything that comes from
naturally occurring foods, plants, etcetera, things
that grow out of the ground, that that's all safe, that's not true. And people that think that pharmaceuticals are the if it's not evidence
with the purified molecule, then something's not of utility. Well, that's certainly not true. somewhere in the middle,
I think lies the answer, which is, it sounds to me like tart cherry is at least an
intriguing potential sleep aid. Intriguing potential sleep aid and underscoring potential. I'm certainly intrigued by it to the point where I
might experiment a bit, but I'm an experimenter for myself. Before I ask you about kiwi, I've had quite good results from taking something called apigenin, which is a derivative of chamomile. But in supplement form, I
think I take 50 milligrams about 30 minutes before sleep. And I subjectively experience
a better night's sleep, so to speak. I don't measure I confess,
I don't measure my sleep. I'm not a sleep tracker guy. But, you know, there are
a few papers out there they're not what we would call blue published in Blue Ribbon journals, but they have control groups, and it looks somewhat interesting. And there when I say apigenin people get somewhat
intrigued oh this molecule. Chamomile has long been
thought to be a sedative, a mild sedative, but a sedative? Do you drink chamomile tea? Do you take apigenin? What are your thoughts on apigenin? - Yeah, I don't. And I have looked into some of the data regarding sleep as well. Right now from best I can tell it's mostly subjective data rather than objective hard
sort of sleep measures. And that's why right now I you know, it's sort of unclear not no
comment, but just unclear, not dismissing it, because I think you and I both ascribe to the idea of absence of evidence is not evidence of absence. So keep your mind open, at
least I tell that to myself. I think if you're finding a benefit, and you can do what I would think of if I was personally experimenting, which is both the positive and negative parts of the experiment, what
I mean by that is, you know, let's say that I now want to, you know, think about some kind of sleep supplement, I will take some kind of
baseline set of recordings for a month, and I will
just gauge where I'm at, sort of supplement free. Then I'll go on for a month or two, whatever I'm thinking of taking, and I don't, you know, supplement. But let's say that I want to
and I experiment with that. And I feel as though based on my metrics be them objective from my aura ring or be them subjective from
whatever I'm, you know, writing down in the morning, and both are important and valid, subjective and objective, we
like both in the sleep world. And I think, okay, look, it's clearly that it seems to have some kind of an effect. The key thing, however, is then
do the negative experiment, which is now come off it
for another month, and see, do things get worse. And if I can see that by directionality, then I'm starting to think maybe I'm believing
this a little bit more. So that's the way I would sort of typically approach you know,
a supplementation regiment if I were to do it. And that's just me, that's just
the way my mind works, but. - No, that's great. I think it's very scientific and organized in a way that allows you and would allow other people to make very informed
decisions for themselves. I like that. I like to think in terms of manipulating any aspect of our biology, that behavioral tools always
are the first line of entry, then nutrition, everyone
has to eat sooner or later, even if you're fasting, then perhaps supplementation, then prescription drugs, and then perhaps brain machine interface, devices that you use to induce something. And those can be done in combination. But what concerns me is
when I hear people say, well, what should I take without thinking about their behavior, their light viewing behavior, etcetera. But of course, these
things work in combination. - And I think it's, you're right, that there's many when it comes to sleep, there are many low hanging fruits that don't necessarily
require you to, you know, put sort of exogenous molecules in other words things like
supplements into your body or, you know, use different types of drugs to help you get there. Now, when it comes to
prescription sleep aids, I think I've been again a
little bit too forthright. We know in clinical practice
that there may be a time and a place for things
like sleeping pills, they are a short term solution to certain forms of insomnia, but they are not recommended
for the long term. And we also know that there
are lots of other ways that you can get a sleep help or you can get a sleep curative profile from things like cognitive
behavioral therapy for insomnia, which is a non drug
approach, psychological. - And quite effective from
what I understand, good data. - Just as effective as
sleeping pills, great data more effective in the long term. There's a recent study published that after working with a therapist, some of the benefits lasted
almost a decade, you know, now, if you stop sleeping pills, usually you have rebound insomnia, where your sleep goes back to being just as bad if not worse. And I think the same is true, when we think about supplementation, there are so many things that are easy to implement
when it comes to sleep, that don't require venturing
out into those waters. And again, we're not here to tell anyone about whether they should venture or not, that's completely your choice. All I'm saying is that if
you want to think about optimizing your sleep,
there are a number of ways that you can do it that don't necessarily require you to swallow
anything or inject anything or you know, smoking or
anything, or free base. - And of which the margins of
safety are quite quite wide. That's the other one. - Yes, right thank you. So speaking of low hanging fruit, I don't know how it hangs in reality, but what about kiwi? They're delicious to me anyway. - Yeah, the humble kiwi fruit named not shouldn't be mistaken for the flightless bird of New Zealand, which is the native bird there. We're talking about the
kiwi the fruit here, which those trees and shrubs
are mostly South East Asia. Kiwi fruits have been previously touted as potentially having a sleep benefit, which again got me curious
and I at first threw it out. To my knowledge, there's really only one published human study that's of any value. But what they did find was that it decreased the speed of time with which it took you to fall asleep. - These are you ingesting the whole kiwi. So it's ingesting the whole kiwi. - With the skin, I eat the skin, people cringe when they see
me, or don't eat the skin? - Well, I think, no, no, no, I think the idea is some of the good stuff and I'll come on to this may
actually be in the skin itself. - Oh wonderful, thank you. You just helped me win a bet. I'll give you your cut. - Okay, okay, yeah, you can pay me later. By the way this skin is use? No, no, no. He just told me to say that's how he wins, no, he did not. So the skin seems to be part of this potential sleep equation. And that study, you fell asleep faster and you stayed asleep for longer and you spent less time
awake throughout the night. And I just thought, well, you know, that's one study, what can you really do with that? There was another study,
however, in an animal model, which is, you know, a
little bit more interesting. And once again, they found
a very similar phenotype that the rats, sorry they were mice, the mice fell asleep faster. And they also spent longer time in sleep. The sleep duration also increased. What was also interesting mechanistically and this is not the mechanism that I think ties together
tart cherries, kiwi fruit, and you know things like melatonin, because I think there could be
one common binding mechanism. What they found in the animal study is that they could block
those kiwifruit sleep benefits using a GABA blocking agent. Now GABA which stands for
Gamma Amino Butyric Acid is one of the major
inhibitory neurotransmitters of the brain. It's kind of like the red. - So a naturally occurring
sedative, sort of? - Yeah, it's the kind of the red light on the traffic light signal, you know, others are green light. GABA is red light. So by playing around with
some sort of clever drugs to manipulate the system, they could prevent the
benefit of the kiwi fruit by sort of buggering around
with the GABA receptor, meaning that perhaps part of
the kiwi fruit benefit on sleep was mediated by the brain's natural inhibitory neurotransmitter
system called the GABA system. - That's exciting.
- And I thought that that was kind of, that convinced me a little bit more that maybe there's
something here to read into. So to be determined,
again, here is the banner, but you know, tart
cherries and kiwi fruits the data surprised me, because in part I was so
preoccupied with being you know, I don't know a bit pure-ish about and a bit snobby thinking come on, that's definitely not going to work, well the data certainly found out. [cross talking] - I look forward to a day when supplements are no
longer called supplements, because at the end of the day, whether or not something has an effect, whether or not it's a whole kiwi fruit or a derivative of kiwi fruit will depend on the molecular compound. And as you mentioned,
this potential mechanism via the GABA system, we both as scientists get
excited about mechanism 'cause when you can trace
a mechanism and a pathway it provides a rationale
a grounding for why kiwi of all things or
tart cherry of all things might help increase total sleep time. I'd be remiss if I didn't mention or ask about tryptophan and serotonin. I can anecdotally say,
when I've taken tryptophan, the precursor to serotonin,
or serotonin itself, I have a horrendous night's sleep. I fall asleep very easily. And I experience
ridiculously vivid dreams. Neither pleasant nor unpleasant
is kind of a mishmash. And then I wake up and I experience several days of insomnia. That and I've done the positive control and the negative control and all the variations
there of to confirm that, at least for me supplementing
with serotonergic agents is a bad idea for me. And tryptophan is a
common sleep supplement and sleep aid that's discussed. The normal architecture of sleep involves the release of serotonin, but in a very timed and regulated way. What are your thoughts
about serotonin in sleep? If you had to kind of
put that into a nutshell. And then why supplementing with serotonin and or its precursor, tryptophan might be a good or a
bad idea for somebody. - I think one of the potential dangers is that based on what's
going on in your body, that can change the absorption of natural sort of tryptophan
and serotonin uptake within the brain itself. So I'm always thoughtful when you're playing around with that mother nature
dynamic as it were. The data as you described is
a little bit all over the map. Some people say that it knocks them out other people say just like you do, it has a terrible impact on my sleep. And when I stop, it's pretty
bad for a couple of days, it seems to have this
lingering after effect. I think what could be happening here is we need serotonin to
just as you described, to be modulated in very specific ways during the different stages of sleep. If you look at the firing
of the brain epicenters where serotonin is released, and there's a bunch of
them in the brainstem, what you find, and the
release of serotonin too, when we're awake, it's usually
in high concentrations, as we start to drift off
to sleep, it lowers some, but not necessarily dramatically as we're going into non REM sleep. But then when we go into REM sleep serotonin is shut off. The other, one of the other
neuromodulators noradrenalin also shut off. REM sleep is the only time
during the 24 hour period, where we see noradrenaline and serotonin or norepinephrine, completely shut down. When I say serotonin,
we're also talking 5-HTP, sorry, 5-HT, that's just
its chemical name here. So whether it was speaking
about serotonin or 5-HT is the same thing. Norepinephrine, noradrenaline, both of those need to be shut down for you to produce REM sleep. The other, one of the
other neuromodulators, that then ramps up to produce
REM sleep is acetylcholine. So these three neuromodulators have this incredible
reciprocal dance that they have for you to generate what is called a natural architecture of
sleep throughout the night. - It's the push pull again. - It's a push pull again, you know, it's you know, it's just and back. It's, you know, whatever
you want to think of. That's why I think if
you're trying to increase dramatically drive up your
serotonin levels at night, and that sustains throughout the night, when you're trying to get into REM sleep, you could be artificially
fragmenting REM sleep. Now, I don't know the data, I don't think anyone's
really got the data. - No, I haven been able to find it. - But that's why I would be, you know if you were to
say, Matt, two years time, that's the data helped me
understand the potential mechanism or let's design some experiments, where would you go first? I would say let's look at
the disruption of REM sleep, non REM sleep, reciprocal regulation, because, you know, you need
serotonin to be, you know, up at one time down at another, so. - I agree with everything you said. And I'm personally never taking tryptophan or serotonin again, unless there's some
clinical reason for that that I would need to do that. I want to ask about some
other pro sleep behaviors. But before I do that,
let's talk about naps. I love naps. I come from a long history of nappers. My dad always took a nap in the afternoon, I take a 20 or 30 minute nap or I do a practice which I
took the liberty of coining NSDR, non sleep deep rest, some sort of just passive laying out their feet up elevated. Sometimes people do you
or I'll do yoga Nidra, I'll do hypnosis or
something of that sort, but 20 or 30 minutes of that has been very beneficial
for me to get up from that nap or period of minimal
wakefulness, we'll call it and go about my day quite well, and also fall asleep just fine. What are the data on naps? Do you nap? And what are your thoughts
about keeping naps short meaning 20 to 30 minutes
versus getting out past 90 minutes, two hours? So for you personally
naps, yay, nay or meh? - I don't nap. And I've just never
been a habitual napper. - Is that because you don't feel sleepy in the afternoon, or because? - I typically don't feel sleepy? - So you're just hardier then. - I am, I wouldn't say hardier, I may be less capable of
falling asleep, my sleep drive. - But you're not dragging
through the afternoon? - No, no, I don't drag through out the. - So you don't nap because
you don't feel a need to nap? - That's right, yep. Now, it's not that I am immune to what we call the
postprandial dip in alertness. I definitely feel as though there can be this kind of afternoon lull, where, you know, I'm
not quite as on as I was at 11 o'clock in the morning. And we know the physiology to that, which brings us back to whether
we were designed to nap. So for naps, we've done
lots of different studies and other colleagues have
done these studies too. Naps can have some really great benefits, we found benefits for
cardiovascular health, blood pressure, for example, we found benefits for levels of cortisol, we found benefits for learning and memory, and also emotional regulation. - How long are the naps,
typically, in those studies? - Anywhere between 20
minutes to 90 minutes. Sometimes we like to
use a 90 minute window so that the participant can
have a full cycle of sleep, and therefore they get
both non REM and REM sleep within that time period. Then when we wake them up, we usually wait a period of time to get them past what
we call sleep inertia, which is that kind of window of grogginess where you say to you,
better half look, you know, darling, please don't speak to me for the first hour after I've. - Don't anything right now. - After the first hour
of waking up, you know, I'm not just, I'm just not
the best version of myself. So we wait for that time period, and then we do some testing. And we've done some
testing before and after, and we look at the change. And that's how we measure
what was the benefit of naps and the reason why we
sometimes do 90 minutes so that they get all of
those stages of sleep. And then we correlate, how much benefit did you get from the nap, and how much of that
benefit was explained by what REM sleep you got,
what deep sleep you got, what light sleep you got? So that's the only reason that we use that as an experimental tool. What we've also found is that naps of as little as 17 minutes can have some quite potent
effects on for example, learning. None of this is novel, NASA pioneered this back in the 1990s. And during the missions, they were experimenting with
naps for their astronauts. And what they found was that
naps of little as 26 minutes, improved mission performance by 34%, and improved daytime alertness by 50%. And it birthed what was then called the NASA nap culture throughout all terrestrial NASA staff during that time period. So it's long been known that
naps can have a benefit. Naps, however, can have
a double edged sword there is a dark side to naps. And it comes back to
our story of adenosine and sleep pressure. The longer we're awake, the more of that sleep pressure
adenosine that we build up. But what I didn't tell
you is that when we sleep, the brain gets the chance to essentially clear out that adenosine. And after about 16 hours of wakefulness, and then after about eight hours of sleep, eight hours of sleep seems to be able to allow the brain to decrease
its adenosine levels back to normal. And so naturally, we
should start to wake up which also aligns with
your circadian rhythm. And those are two separate processes. But with about eight hours
of good quality sleep seven to nine hours for the average adult, we are free of all of that adenosine. We've evacuated it
essentially out of the brain, and we wake up naturally
feeling refreshed. The reason that naps can
be potentially dangerous is that when you nap, you are essentially opening the
valve on the pressure cooker of sleep pressure. And some of that sleepiness
is lost by way of the nap. So for some people and not all people and you're a great example of this. Some people, however,
if they are struggling with sleep at night, and
they nap during the day, it makes their sleep problems even worse. So for people with insomnia, we typically advise against napping. And the advice is if
you can nap regularly, and you don't struggle
with sleep at night, then naps are just fine. But if you do struggle with
sleep, stay away from naps. If you are going to nap, try to limit your naps,
try to cut them off a bit like sort of caffeine, maybe you know, eight to 12 hours maybe
not that you know far off maybe sort of seven to six
hours is a good rule of thumb. Try not to nap essentially
late in the afternoon. And if you do take a nap and you want to maintain your you don't want to have
that grogginess hangover that can happen after
a full night of sleep for the first hour, try to limit it to about 20, 25 minutes. And that way you don't go down into the very deepest stages of sleep, which if I wrench you
out of with an alarm, then you just kind of feel
you almost feel worse, for the first hour after the nap. - I've definitely experienced
that if I oversleep. Certainly if the sun
goes down during my nap and I wake up and light overall lighting conditions have changed, I find it very hard to jolt
myself back into the evening. And it can screw me up. So I try and keep those naps pretty brief. And I should say, I'm very happy to hear you
mention individual differences and why some people might want to nap and other people might not want to nap, I have a colleague Liqun Luo he'll be familiar to many neurobiologist. - Yeah of course. - Who's a absolutely
spectacular scientist, member of the National Academy, Howard Hughes investigator just a phenom, and has a ton of energy. But years ago, I learned that he always takes a
nap in the afternoon, so much so that when he travels to give seminars at other universities, he will tell his post lunch host whoever it is that he's
supposed to meet with, may I have your office
for 30 minutes of our, sometimes 30 minute discussion
or 60 minute discussion, because I like to take a nap. And he does that and then gives us his, his talks are typically in the afternoon in academic culture. And he describes the
effect of the nap for him this short naps in the afternoon being so profound for his productivity. That's actually what inspired me to start feeling okay
about my desire to nap. And so I think for me, that was great vindication for
those that might feel guilty about wanting a nap. But I take to heart your note about avoiding naps if you have trouble falling and staying asleep, 'cause I think that I have family members who also if they nap, they're
a wreck, they can't sleep. - Yeah, I think it's just, we've often been very pro sleep with sort of the sleep community. So I think it's good to always point out these potential dark sides of any aspect. But you're absolutely right, no one should feel guilty
about getting the sleep that they need. And I think that's been one
of the big problems in society society has stigmatized
sleep with these labels of being slothful or lazy. And we're almost embarrassed, you know, to tell colleagues that we take a nap. I think sleep is a write of human beings. And I therefore think that
sleep is a civil right of all human beings. And no one should make you feel unproud of getting the sleep that you need. - No, I love that. And I it's an important point. I also feel that one of the best ways to beat your competition in any
endeavor is to outlive them. So now that we know that
sleep can enhance longevity and lack of sleep can shorten one's life, that's all the
justification I need anyway. Can somebody sleep too much? Is it possible to get too much sleep? - It's a very good question. And there are probably two
things to say about it, there is a condition
that we call hypersomnia. But that's a mixture of things, it's where people have either a very high sleep need, or they are very sleepy during the day. And they're typically falling asleep. And these can happen in a variety of different clinical contexts. One of the places where we've often seen hypersomnia believed to
manifest is in depression. But if you look at some of those studies, it turns out, it looks more as though those people are simply
reporting being in bed longer, but not necessarily sleeping longer. And that fits very well
with one of the profiles that we know of depression, which is anhedonia, you don't get pleasure from
normally pleasurable things. So you just don't want
to go out into the world, you don't want to interact
because you're depressed. So what do you do? You just stay in bed? - Blinds closed, watching
TV, on the phone. - [Matthew] Right, and that
just looks as though you know, - Felling miserable.
- When people say, what time did you go to bed? And what time did you get out of bed? The mistake made in that question is okay, that's how much time their sleeping when you should have said, what time did you fall asleep? And what time did you wake up? And the answer could be very different. So that's hypersomnia
from a clinical context. Can you sleep too much though? One of the data points that
argues yes, that's possible is when we look at all cause mortality. Certainly what you find is that using the sweet spot
of seven to nine hours, when you start to draw below seven hours, there is a relationship, which suggests that the shorter your sleep, the shorter your life. Short sleep in that regard
predicts all cause mortality. But it's again, not a linear relationship like the one that we've
seen with REM sleep. Once you get past nine hours, the mortality curve stops going down. And then once you get
further 10 or 11 hours, it hooks back up again,
it's almost like a J shape, tilted over a little bit and reversed. So there's this strange
hook, what's going on here? Right now, sleep science has at least two non mutually exclusive
explanations for this. The first is that if you look
at some of those populations, the idea is that the whatever
was causing them illness and took their lives was just too much for sleep to deal with. However, we know that when we get sick, one of the things that we do immediately in this whole mechanism
and inflammatory mechanisms cytokine mediated, when we get sick, we want to sleep more. We just want to curl up in bed
and you know, sleep it off. So the argument there is that it's not that sleep was
killing people prematurely, it was that these people
were calling on this the help of sleep, they were calling on this thing called the Swiss Army Knife of
health, that is sleep. But whatever it is that they were facing was just too powerful
for sleep to overcome. So it artificially looks as though more sleep leads to a
higher risk of death, when sleep is actually
responding to the mortality risk, and it lost the battle. That's one argument. The second is that we
know that sleep quality and poor sleep efficiency is a very strong predictor
of all cause mortality. And when you look at
people who often report sleeping longer amounts, 10 or 11 hours, they typically report having
very poor quality sleep. So because their quality of sleep is poor, they just try to sleep longer to try and get some of that back. So again, here now it's poor quality sleep masking as too much sleep leading to this artificial hook which looks like mortality. That's the second explanation. A third which is more of a Gedanken, which is just the kind of
like a thought experiment and I have this mentality, I don't know how many
other people share this. I actually think that could
be a thing as too much sleep. Physiologically, I think it's possible. But the reason I think that is because it's no different
than food, water or oxygen. Can you overeat? Yes, you can. Can you under eat? Of course.
- Or light. light in the early part of the day, throughout the day, wonderful. Light late in the day and
at night, detrimental. - Bi-directional, you know, for
water, can you over hydrate, hypernatremia it can lead, you know, it happened in the 1990s and
2000, with the ecstasy craze, where governments were
saying you're dehydrating you're dancing all night,
please drink water. And they drunk too much water, their blood electrolytes went
you know, all over the place, and they were having
cardiac arrests or stroke. - Yeah people were dying. - And they were dying because
of excessive hydration. Can you get too much oxygen, hypoxemia? And it can cause free radical damage, which can be profoundly
harmful and kill brain cells. Can you sleep too much? You know, which is the fifth
element of the life equation, you know, alongside you know, food, water, oxygen, you know, so forth. I should say I can't even count. Clearly I'm sleeping well. Yes, I think that could
be that possibility. Are most people in danger
of getting too much sleep? Or contrary, if you look at the data. So but I don't dismiss that idea. I think it's possible. - That's a very thorough and very nuanced, and yet very clear answer. So I, it's so interesting to think that a lot of the data that's out there that talking about being in bed too long that it's just trying to compensate for the actual fragmentation of sleep. So what I'm coming away with is that there are many paths to this and both positive and things to avoid. But the idea is to get most nights, a similar amount, probably
seven to nine hours, somewhere in there, of high quality sleep. That this notion of sleep
quality is going to become, I would hope, a phrase that
more people think about and learn about and
cultivate as a practice. I want to ask about a set of behaviors that I'm at least I'm aware
of at least one company is starting to track in their
sleep monitoring device, and that's orgasm, and sex
orgasm and masturbation topics that are, you know,
are somewhat sensitive. But from the perspective
of biology, right, none of us would be here were it not for sperm meets egg in some fashion, either in a dish or in vivo. But what are the data
as you know them to be or maybe your lab is even
doing this kind of work and exploration about the role that sex, orgasm, masturbation play in getting to sleep and staying
asleep and sleep quality? Certainly those behaviors and those physiological events have been part of our
evolutionary history. What's the story there? What can we say about
this in terms of science and dare I say practice? - Yeah, I mean, it's almost
that caricature of you know, in the movies where, you
know, a couple makes love and then all of a sudden,
you just sort of hear snoring or, you know, that happens with the idea that it somewhat some neurogenic that it's sleep promoting. - Well, the post orgasmic
increase in prolactin. - Well, that's very, is interesting. - Is thought to be a set a naturally occurring sedative, that presumably has a function in. - And oxytocin has that also that benefit where you see, you know, a dissipation of the
fight or flight branch of the nervous system, which has to happen
for you to fall asleep. That's why we often see, you
know, here at The Sleep Center, we'll see a phenomenon
called wired and tired where people say, look,
I am so desperately tired I just I'm so so tired, but I can't fall asleep,
because I'm too wired. So your sleep drive, you're
desperately tired, it's there but because you're wired, because you've got too much
sympathetic activation, too much cortisol as well, you can't fall asleep. It's an impressive roadblock
to anything like good sleep. And it's one of the principal mechanisms that we now believe stress
and physiological activation, that is the underlying cause
of many forms of insomnia. But coming back to sex, the data is actually quite compelling, that both either subjectively
assessed sleep quality, or objective amount of sleep, sex that has resulted in orgasm, and I think it's that latter part that typically needs to happen. - I would imagine so. - That, you know, so between two mutually exclusive individuals, where both are, you know, beneficial in terms of receiving an orgasm. [cross talking] - Yeah, I would say any
discussion about sex, we were referring to
consensual, age appropriate, species appropriate, context appropriate. - Wow, I would never have even gone to the species appropriate. - I put species in there
because it's the internet, and people will come up
with all sorts of ideas. So I think that age appropriate, I think age appropriate,
consensual, context appropriate and species appropriate,
covers all the bases, but if I missed any, put
them in the comment section, and we'll be sure to take note. - Yeah, no, I think
that's really well said and important to say. So the data that is the
when you look at couples who have orgasm. We've also, however, found
benefits of masturbation, and it's not frequently spoken about. But what if you do some surveys, it turns out that people
will often use masturbation as a sleep tool, if they're
struggling with sleep. And I know, this sort of sounds almost like a strange conversation,
or it's a taboo conversation but I think we just need to be
very open about all of this. - I started off in science, one of the things I worked
on early in my career, not the very first topic was the topic of early
influences of hormones, estrogen and testosterone
on sexual development of the brain and body. And when you are weaned
in a laboratory like that, regardless of what era, you look at sex and its
behaviors, and its hormones, and its physiologies as a scientist, and so that's to be clear
what we're doing here, we're exploring these behaviors
from that perspective. I mean, one thing is for certain, everyone is here because
a sperm met an egg, either in a dish or in
vivo, as we said before, and at least in 2021, there's no way around that fact. And what preceded that is
typically this act we call sex and sometimes, hopefully, I like to think orgasm is associated with
that sexual activity. Masturbation is one dimension of that is something that I think it
can and should be discussed, if in fact, there are data
that relate it to sleep. - Yeah, and both of those routes seem to lead to a sleep benefit. Now, I'm not saying that
it's all about the orgasm. I think as we spoke about with oxytocin, there is some degree of par bonding that if you have a partner, and you experience you know,
an intimate loving, you know, relationship that involves that, then you can have hormonal benefits that are sleep promoting, that may not necessarily be seen if you're just engaging you know, in the solo singular act of masturbation. So what we certainly know and I am not someone to take any advice on when it comes to anything
relationship wise or sex wise. - That's a different
episode of the podcast. - Yeah, yeah certainly. And that's not a podcast series that I'm going to be
releasing anytime soon, it's going to be mostly about sleep. Although I will touch on, I'll release a podcast on sleep and sex. But that's the data that we have so far. We also know that it
works both ways, though. And it's commonly the same way with sleep. You know, sleep and
exercise, sleep and diet. How you eat can affect how you sleep, how you sleep can affect how you eat. Same with exercise. And it turns out, it's the same way with
sexual behavior, too. So here, we're talking about whether sex can help with sleep. Can sleep help with your
relationship and sex? And the answer is, yes, it can. Firstly, we know and we've
spoken a little bit about this, that the reproductive hormones are under profound sleep regulation. - Both estrogen and
testosterone, I understand. - Estrogen, testosterone, as I said. - Cause we hear so often
about testosterone. But women who, or I should
say anyone who's interested in having higher levels of estrogen or normal healthy levels of estrogen I presume the data show for estrogen what the data also show,
similarly for testosterone. Which is if you get too little
or poor quality of sleep both sex steroid hormones,
as they're referred to testosterone and estrogen, which are present in
both males and females and every variation thereof, are going to be diminished below normal healthy levels, correct? - Yes, estrogen,
testosterone, FSH in women, a key hormone in the regulation for, key for conception, of course, all of these sex hormones seem to become significantly disrupted when sleep becomes of short
quantity, or poor quality. We also know that in women, sleep disruption can usually lead to menstrual cycle disruption. We know this, particularly from evidence in shift working women where they are nighttime shift workers, they struggle with sleep during the day, often menstruation is disrupted or even becomes impaired. But we also know it works this way, not just for sex hormones,
but for sex itself. For example, we found that
for every one hour of sleep, extra sleep that a woman gets her interest in becoming sexually
intimate with her partner increases by 14%, which is, you know, a non trivial amount.
- Substantial. - And then the final part
of I think this equation when it comes to sleep, and sex is your relationship itself. And there's some great
work here from UC Berkeley by Professor Serena Chen. And what she found was
that restless nights mean for far more brutal
fights in your relationship. And they did this.
- And vice versa. - A number of different elegant ways, and vice versa as well. - I mean, not that I've ever
had conflict in relationships. [cross talking] - You know, just this is data I've read, I've never experienced that at all. So, they found reliably
that sleep would predict higher likelihood of
relationship conflict. Secondly, if you got into that conflict, the chances of you resolving it were significantly lower when the parties had not been sleeping well. Part of the reason is because when you are not well slept,
your empathy goes down. So you're not, you're taking more of an abrasive stance with your partner, rather than a more agreeable
stance with your partner. So at almost every dimension
of a human loving relationship, sleep can have a dramatic impact. - I think these are really
important things to underscore, one of the most common questions I get, because there seems to
be community of people on the internet that
are obsessed with this. I don't know who they are, because it's all, all this internet stuff
is shouting into a tunnel and getting comments back in written form. It's a very bizarre
conversation, so to speak. Is whether or not sexual behavior itself lowers or increases testosterone? And I went into the data, which spans many decades actually, both animal studies and human studies. And it seems just to underscore this as long as we're talking
about this subject that it does seem that sexual activity, sex between two people does seem to increase
testosterone in both. There is this question
about orgasm or no orgasm ejaculation, no ejaculation and indeed, there do seem to be some effects of restricting ejaculation in males as a form of further
increasing testosterone. So sex without ejaculation
further increasing testosterone. But the data are not clean. Presumably because organizing
these sorts of studies and getting truth in self reporting is probably hard to get from subjects. But everything sort of
points in the direction that provided that the
relationship is a healthy one, it's consensual, it's age appropriate, context appropriate, species appropriate that sex between two individuals does seem to increase
the sex steroid hormones testosterone and estrogen
toward healthy ranges. And what I'm hearing now this sort of Gestalt of the discussion we just had is that that too can promote
sleepiness, restful states, and quality sleep. And I think this is an
important conversation that just hasn't been held enough. I mean, sooner or later,
both in the US and elsewhere, we're going to have to acknowledge that we are biological
organisms of some sort, and that we have choice in life, about all these things, from supplementation to
sex, or no sex, et cetera, but that they have profound
effects on our core biology. I mean, it's fascinating to me that the areas of the
hypothalamus, the preoptic area, the super optic areas, those areas which the names might not mean anything to anybody, besides Matt and I sitting here, but those areas sit cheek
to jowl with each other in the hypothalamus and
control, sleep and sex. The trigger of orgasm,
the appetite for food, the appetite for water for electrolytes. I mean, the hypothalamus
is kind of a festival of neurons with different booths for different primitive behaviors. - It's such a small, small
structure in the brain, but it's the orchestrator of
a vast number of our behaviors disproportionate in terms
of its size versus effect. - Yeah, I don't think you can go to this hypothalamic festival without at least seeing all the booths whether or not you decide
to visit them or not. - I love that master analogy. - So I'm glad that we've
broached that conversation. And I hope people will think
that we've approached it with the appropriate level of sensitivity. It's an important one that
we're going to hear more about one way or the other. People are certainly thinking about this, if not engaging in
these sorts of behaviors or avoiding them. So the more we can understand
about the biology, the better. And so thank you for
bringing that topic up. Because for the record, Matt,
tabled it for discussion. - We were just like chatting outside and I think we said
something about sort of sex, and I said we can go there. There is so much interesting data. - Absolutely, I want to touch
on just two remaining topics. One is are there any
unconventional sleep tips or things about sleep
that we've overlooked? If we've covered everything
great, but you know, we hear to keep the room cool. We hear because of this
temperature phenomenon, the light aspects, the
considerations about alcohol, CBD marijuana, cognitive behavioral, tart cherry fruit, kiwi perhaps. - Please don't put me on the hook for tart cherries and kiwis, I was just offering what
I know about the data. - And these are considerations and whether or not people
batch these things, I won't even list them off now, because they're too many
jokes that one could make. - And I have no affiliation
with any of these products. [cross talking] - Well, I'm going to take
out stock in a kiwi company. No I'm just kidding. But the question I have is about any unconventional or lesser known things, or maybe you do things
or you think about things just in a purely exploratory way, as a scientist of that, you
know, the what if kind of things that, yeah, what if it turns out that and I hear I just, I got a blank there for you to fill in. - I think, you know, beyond
the standard, you know, fair that I've dished out plenty of times of sleep hygiene of you know,
regularity, temperature, darkness, alcohol, caffeine, and we've spoken about all of those. What are some more
unconventional tips, I guess? The first one, which is unconventional along the lines of naps. If you've had a bad night of sleep, let's say that you're starting
to emerge with insomnia and you've had a bad night of sleep, the advice and I learned this
from my wonderful colleague, Michael Perlis, do nothing. What I mean by that is,
don't wake up any later, don't sleep in the following
day to try and make up for it, don't nap during the day, don't consume extra
caffeine to wake you up, to try to get you through the day, and don't go to bed any earlier to think that you're going to compensate. And I can explain all of those things. But if you wake up later, you're not going to be sleepy
until late in the evening, so you're going to go to
bed at your normal time and you won't be sleeping,
you'll think well, I just came off a bad night of sleep. And now I still, I can't even get to sleep
and it's my normal time. It's because you slept in
later than you would otherwise, and you reduce the window
of adenosine accumulation before your normal bedtime. So don't go, don't wake up any later. Don't use more caffeine for
the reasons that are obvious, because that's only going to
crank you and keep you awake the following night or decrease the probability of a good following
night of recovery sleep. Third, I mentioned don't take naps, because once again, that
will just take, you know, naps, particularly later in the afternoon, I almost liken them to
snacking before a main meal, it just takes your appetite off the edge of that main meal of
sleep, so don't do it. And then finally, don't
go to bed any earlier, resist and resist and go
to bed at your normal time. What I want to try and do is prevent you from thinking I had such
a bad night last night and I normally go to bed at 10:30, I'm just going to get
into bed at nine o'clock, because last night was just so bad. But that's not your natural bedtime, and it's not aligned with
your natural chronotype because presumably you kind of know something about that, our morning time, evening time, you're trying to sleep in harmony, which is usually how you
get best quality sleep. But you go to bed at nine, and my body is not ready
to sleep at nine o'clock. But I'm worried because I had a bad night of sleep last night so I get into bed, and now I'm tossing and turning for the first hour and a half because it's not my natural sleep window, but I just thought it was a good idea. And if I didn't know anything about sleep, I would think all of
these same things too. So I'm not finger wagging. But after if I have a bad night of sleep, and I am not immune, just because I know a
little bit about sleep doesn't mean I don't
have my bad nights, I do. Doesn't mean I haven't had bouts of insomnia in my life, I have. But after a bad night
of sleep, I do nothing. I don't do any of those four things. I think the second tip I would offer in terms of unconventional
is have a wind down routine. Many of us think of sleep as if it's like a light switch, that we just jump into bed, and when we turn the light out sleep should arrive in that same way. Just the binary you know
it's on or it's off. Sleep is a physiological process, it's much more like landing a plane, it takes time to gradually descend down onto the terra firma of what we call good solid sleep at night. Find out whatever works for you and it could be light stretching, I usually meditate for about
10 or 15 minutes before bed. Some people like reading, try not to watch television in bed that's usually advised against. - Something that doesn't emit
too much light to your eyes. - Too much light, too
activating, you know, you can listen to relaxing podcasts, although we can speak about
technology in the bedroom too. But have some kind of a wind down routine. It's you know, it's almost like you know, you wouldn't race into your garage and come to a screeching
halt from 60 miles an hour, you typically down, shift your gears and you slow down as you
come into the garage, that's the same thing with with sleep too. So that's the second thing, have some kind of a wind down routine, find what works for you. Maybe it's taking a hot
bath or a warm shower, and then stick to it. Just we do this with kids all the time, we find out what their bedroom, sorry, their bedtime regiment is and then we just stick to it faithfully 'cause we humans are the same way too. The third thing is a
myth, don't count sheep. There's a study done here at UC Berkeley, I didn't do this today, I wish I did, it's by my colleague,
Professor Allison Harvey. And they found that counting sheep actually made it harder to fall asleep. It made matters worse. As a conter sorry counter measure to that what they did find was
that taking yourself on some kind of a mental walk, so think about a nice walk
that you take in nature or a walk on the beach, or even a walk around
an urban environment. - Just visualizing that. - And visualizing that, that
seemed to be beneficial. The other thing about sort of that idea of shifting focus away
from your mind itself, get your mind off itself
is a good piece of advice. Catharsis, you can try to write down all of the concerns that you have, and do this not right before bed, but usually an hour or two before bed. Some people call it a worry journal. And to me, it's a little
bit like closing down all of the emotional tabs on my browser. Because if I shut the computer down and all of those tabs are still open, I'm going to come back in the morning, and the computer's red hot the fans going because
it didn't go to sleep, because it couldn't because there were too
many tabs active and open. I think it's the same
way with sleep as well, so try to think about doing that. So just vomit out all of
your concerns on the page. - I like that, cause my 3am waking is often associated with me writing down the list of things that I
forgot to do that I need to do. And once I eventually wake
up from the later night, second half of the night's sleep, that stuff seems much more
tractable and reasonable, but it sure would be great to get that stuff out
of the way before sleep. - Well, there's also something that I don't think people
have spoken about a lot. And I'd like to research it, which is difficulty and
anxiety at night in the dark, is not the same difficulty and
anxiety in the light of day. And when we have those thoughts at night, it comes with a magnitude of rumination and catastrophization
that is disproportionate to that which you would
describe when you are awake. And I don't know what's
going on about the brain, and thought and emotion at the time, I've got a bunch of theories as to why, and that's why I like
the idea of closing up zipping up all of those
different components, just get them out on the page. And it feel, and I at first thought this
just sounds like who its it sounds very Berkeley,
it's kind of Kumbaya, we all hold hands, and, you know, we all come at the end of the day. But then the data started coming out really good studies from good people. And they found that keeping
one of those journals decreased the time it
takes you to fall asleep by 50%, five, zero. - Amazing that's substantial.
- That's well on par with any pharmaceutical agent. - I'm convinced that I've
long thought that the worries and concerns and
ideas I have at three, 4am I've learned to not
place any stock in them. Because something, I'm glad that you might decide to eventually look
at this in your laboratory because I feel like something
is melted away or altered. I suspect it's in the regulation of the autonomic nervous system, that it makes sense why
a concern at three, 4am ought to evoke more of a panic
sense than a concern sense. And certainly, that's my experience, although not, fortunate to not suffer from full blown panic attacks. But everything seems worse at three, 4am provided you're awake. - And we need to sort of look into that because, you know, if you
look at suicide rates, around the 24 hour clock face, disproportionately higher rates in those middle sort of night hours. So now, I don't know if
that's causative or not, but something you know, it could just be that that's the time when we're mostly lonely,
and we're by ourselves. And that's the reason. So it's got nothing to do
with sleep or the night time, I don't know. So that's the third thing, I think the fourth sort
of little tip I would give that's unconventional,
is remove all clock faces from your bedroom. - Including your phone. - Including your phone,
and resist checking it. Now I know and I can
speak about the phone too that genie of technology
is out the bottle. And it's not going back in anytime soon. So we've got to think a
scientist and sleep scientist, you know, as to what we do with you know, phones in the bedroom. - Years ago, I was a
counselor at a Summer camp I worked with at risk kids and there was a phrase
that comes to mind here, it's be a channel, not a dam. Because when you try and dam
certain kinds of behavior, physically dam certain kinds of behavior and not morally dam, that too, it just creeps over the edge, and you get a waterfall. So it has to be a channel. The phone and devices
have to be worked with and negotiated not eliminated. - That's right and you know, think about those mindfully too but clock faces, remove all of those, because if you are having,
you know, a tough night, knowing that it's 3:22 in the morning, or it's 4:48 in the morning, does not help you in the slightest. And it's only going to make
matters worse than better. So try to remove all clock faces. And I think that's one of those other tips that some people have found helpful. But those would be sort of
some slightly unconventional, I guess more than your stock fare of here are the five tips for
sleep hygiene tonight, so. - Those are terrific sleep tips, and several of which, if not all of which I'm going to incorporate. Matt, this has been an amazing, deep dive on sleep and it's positive
and negative regulators. - I hope it hasn't been too long. - No this has been great. - Please cut it down,
shorten it to, you know, the five minutes of meaningful
stuff that I offered. - Absolutely not, it is chock a block full of valuable takeaways. It's been tremendously fun for me to dissect out this
incredible aspect of our lives that we call sleep with a fellow scientist and a fellow public educator. I want to say several things. First of all, we should say
where people can find you although it shouldn't be
that difficult these days. You're a very present on the internet. - [Matthew] Unfortunately.
- For better or for worse. I think it's wonderful
that you're out there. Look, it's a public health
service that you're doing. No one requires you or any other scientist to get out and share this information. My sense of you knowing you a bit, and from following your work very closely both your scientific work in detail and your public facing educational work is that you very much
want the best for people. And it's an interesting thing
as a scientist or a clinician, to know that the that certain answers exist, that we don't have all the answers, but that there is a better path, there are better ways
and people can benefit in a myriad of ways. So, for that, because I know
that to be very genuine in you, you want the best for people and you're offering tremendous advice and considerations and people
can take it or leave it that's the way I view it. I also want to thank you for
taking the time out of your day to sit with me here and
have this discussion. - Not at all, no at all, it's a privilege, it's a delight, you know, you and I, I think we're alike kind in lots of ways. And I take you as a shining example of how you can effectively
connect with the public. And I know that we've had
our conversations before we ever sat down to talk
together about, you know, how to think about
communicating with the public and the pros and cons of that. And I've just loved your opinions. I've been drinking it all in. And then I think the third
thing I'd like to say is, thank you for being such an
incredible sleep ambassador, the series that you've released on sleep, the way that you speak about sleep, the way that you moderate
and have championed sleep. It is remarkable. So thank you for just being you know, a brother in arms in that way. - But we are and thanks
for those those words. 99% of what I discussed there was the work of you and your
colleagues in the sleep field. So proper acknowledgement, but thank you, where can people learn more about what you're doing currently? And what's coming next? You're on Twitter. - I am on Twitter I typically tweet. - As the sleep diplomat. - So, no it's just sleep diplomat - Sleep diplomat on Twitter. - Sleep diplomat on Twitter,
sleepdiplomat.com website, if you want to learn more about
the science that we do here, it's humansleepscience.com. It's the Center for Human Sleep Science. You can pick up a copy
of the book, if you want. It's called "Why We Sleep?" if you're curious about sleep, that's one path to take and it's my view. - Is there another might
someday in the future? - I think there may be, yeah. - Great, great, many,
many millions of people will be very happy to hear that. - I think it's starting to take hold. And then as we discussed, I am more than kicking around the idea of a short form podcast
rather than a long form, not long form, because I
don't have the mental capacity or the interviewing, just capability that someone like you has. So it will probably just
be monologue short form. So if there is some interest,
I'll probably do that as well. So those are the ways
that people can find me. But overall, if you're
interested in sleep, just listen to Andrew. That's thing I can tell people. - All right, well now
we're bating back and forth the vector of action so to speak, but I do hope you'll start a podcast however brief or lengthy
these episodes turn out to be because I do believe that's a great venue to get information out into the world. And we don't just want to
hear more from Matt Walker, I speak for many people, we need to, the work you're
doing is both influential, but more importantly,
it is important work. It has the impact that's needed, especially in this day and age where science and medicine, public health, and the issues of the world, etcetera, are really converging. So I know I speak on behalf of a tremendous number of people, when I just say thank you
for doing the work you do and for being you.
- [Matthew] Thank you. - And thanks for being a good friend. - Likewise, too and by the way, I'm just going to note that it was nice that the two of us both got the Johnny Cash memo
about how to dress today. It seems as though we're both
kind of we got that same memo, which will mean nothing to
people who are listening, but if you're watching the video, you'll probably see what I mean. Andrew, thank you for taking this time. Thank you so much. - Thanks so much Matt. Thank you for joining me for my discussion with Dr. Matt Walker. Please also check out his
podcast the Matt Walker podcast. A link to that podcast can
be found in the show notes. If you're enjoying this podcast, please subscribe to us on YouTube. On YouTube, you can also leave us comments and suggestions for future episodes and guests in the comment section. As well, please subscribe to
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beginning of this episode. Links to those sponsors can
be found in the show notes. During this episode, and
in many previous episodes, we discuss supplements. One issue in the supplement industry is that many supplements don't contain what's listed on the bottle. We therefore have partnered with Thorne, that's T H O R N E, Thorne supplements, because Thorne supplements have the highest levels of stringency in terms of the purity of the ingredients, and precision with respect to
what's listed on the bottle is actually what's contained
in those supplement bottles. If you'd like to see the
supplements that I take for sleep, and for other things, you can
go to thorne.com/u/huberman and there you'll see all
the supplements that I take and can get 20% off any
of those supplements as well as any other supplements that Thorne happens to make. That's Thorne, thorne.com/u/huberman. And last, but certainly not least, thank you for your interest in science.
