Sunlight: Optimize Health and Immunity (Light Therapy and Melatonin)

[Music] as a doctor you have four board certifications one of which is sleep medicine so you spend a lot of time researching how light impacts us as human beings and i know you're very excited about this topic the average american spends 93 of our life indoors that's 87 of our life is inside buildings and another six percent on average inside automobiles so tell us why you're so excited about this topic and are we going to get some practical tips that we can implement right away yeah thanks kyle i became excited about this because as i started to learn about what scientists are discovering it was mind-blowing i mean we know about ultraviolet radiation from the sun and its role in producing vitamin d in our bodies but there's a whole other aspect to the light that we get from the sun and light that comes outside for instance the visible spectrum and how it affects us the infrared spectrum and how it affects us we are now starting to see what scientists are finding is amazing and beyond the science of this which we'll talk about we're going to give you practical tips to harness that information and actually apply it to your body so that you can help optimize your immune system and as you'll see the results of that can also help in things like covet 19 and and general infections but the information in this video i believe is so important that everybody needs to be able to understand this and that's the reason why i'm so excited to talk to you about light so to explain why light is so important to the human body we've got to get down to the cellular level and explain this sort of at the outset and to do that i'm going to use an analogy to help explain what i'm talking about so in every cell of our bodies we have something called mitochondria are like the engine in a car it produces the power the energy and for the body it produces atp which is the currency of energy for our body but just like the engine in your car it can overheat and it can shut down and that's a byproduct of what it does and it's a very similar situation that happens in the mitochondria the mitochondria takes the food that you eat the fats the proteins the carbohydrates and it makes the atp that your body needs but a byproduct of that is oxidative stress that's the heat around the engine that if the oxidative stress builds up too much it can cause problems so what are some problems you can run into if you have too much oxidative stress what scientists have discovered and looked at over the years is that there are a lot of consequences to oxidative stress less optimal health inflammation cancer dementia diabetes and learning disabilities have been tied to oxidative stress in the mitochondria and mitochondrial disability okay so mitochondria are in all of our cells and you've given the analogy that they're like a car that they can overheat and have problems so a car's got a cooling system what would be the cooling system if you will in our mitochondria so actually the body has two different systems to be put in place that takes care of the mitochondria in terms of cooling it down or getting rid of the oxidative stress in the mitochondria depending on whether it's day or night and i think that's fascinating many of us know about what the cooling system is at night because we've heard of it before and one of the things that is done is that melatonin which is one of the strongest antioxidants that has been studied it actually up regulates the glutathione system is twice as powerful as vitamin e melatonin is secreted at night from the pineal gland goes into the blood circulation goes into the cells and is actively transported in and then goes into the mitochondria to fulfill its duty to mop up very efficiently these oxidative stress molecules okay let me see if i'm following this so in the evening melatonin's released from the pineal gland and we've all heard that melatonin can help us sleep people take melatonin as a sleep supplement i know it's important for that but you're saying it also goes into the mitochondria of our cells and combats oxidative stress that's exactly correct okay so that process works at night how do mitochondria in our cells deal with oxidative stress during the day well that's a very good question because any type of light that hits the human eye is going to shut down the production of melatonin from the pineal gland and so there has to be a completely different system that is put in place during the day that allows melatonin to be made in the mitochondria to deal with the oxidative stress remember we said that these hydroxy radicals these oxygen radicals that are produced in the mitochondria as a result of metabolism can destroy things immediately in its vicinity so you need to have antioxidants right there on site and so the question is is exactly how does this happen during the day and the answer is that infrared radiation from the sun which we'll talk about actually goes into the mitochondria and is producing melatonin on-site this is what the science is now starting to discover making it very interesting as to how much sunlight are we getting and what happens when we don't get enough sunlight so is oxidative stress always bad for us no oxidative stress can actually be beneficial if it's in the right place so oxidative stress in the mitochondria is just going to serve to break down the proteins of the electron transport change which we'll talk about as we get into this lecture but it's very important for cells for instance like white blood cells which are responsible for killing bacteria to have within them the ability to have oxidative bursts and oxidative stress so in certain places at certain times oxidative stress can be very beneficial but in the mitochondria no the body needs systems in place to protect the mitochondria because it's doing a very important work many of us have heard that not all light from the sun is visible light so can you break down the solar spectrum for us yeah kyle let's take a look at the solar spectrum which looks at the energy coming from the sun sometimes i don't like to use the word light but i will use it because it assumes that light is something that we can see but clearly there is energy coming from the sun which we cannot see and that's important to understand as we look here at the solar spectrum you'll see that 39 just 39 of the energy coming from the sun is in the form of visible light and we can see that here between 400 nanometers and 760 nanometers wavelength we'll talk about wavelength and so you can see everything to the right of red is known as infrared because it has a wavelength longer than red and that is divided up into near infrared and far infrared we'll talk about this more later don't get too concerned about this but specifically we're going to talk more about near infrared and its benefits and that's between 760 nanometers and 1400 nanometers we'll come back to that at the other end all of the light as you can see that is beyond the purple or violet in this case ultraviolet is not seen but we know that it's important specifically uvb is important in making vitamin d but i want you to notice something very important 54 of all the energy coming from the sun is in the infrared spectrum remember that we're going to come back to that okay so the sun is putting out a lot of energy and of that energy a spectrum of that is visible light are there other aspects of visible light that we need to know about at this time yeah so in order for us to give recommendations and for us to be able to measure the effect of light one of the things that's really important is understanding what lux is and so we've got an example here where we have a candle which is one lumen one meter away from a board which is one meter by one meter and that's described as one lux i'm saying this because we're going to be using lux a lot so you have to understand that one lux is pretty dim light in fact let's talk a little bit about some different examples so you can understand what lux really is and in this slide here you can see that one lux is kind of like twilight at night and that a family living room is about 50 lux but it can go all the way up to a thousand if you had an overcast day outside and if it was a bright and sunny day that would be around 100 000 or even more lux so that kind of gives you an idea when we talk about exposing your eyes to light at a certain lux level this is a good reference point for understanding light and its intensity with that information now we're ready to talk about light and how it affects the human body this is going to be divided into two parts the first part is going to be what happens at night how we divide the night from the day and how sleep and the circadian rhythm is affected by light the second part is going to be on how light affects us directly with infrared radiation and the mitochondria and i think that's going to be the part that for most of you you've probably never heard before so stick with us as we go through this there's going to be a lot of interesting informative aspects of this talk but first let's talk about how sleep and the circadian rhythm is affected by light so if you've ever been to a concert you know that the conductor is the one that's conducting the orchestra and each one of those players in the orchestra is starting at the beginning of their music and playing their instrument they all have to start at the same time otherwise the music is not going to sound right so in the body there are many different types of processes going on there is a violet in one portion of the body there is a tuba going on in another portion of the body to use that analogy but to make sure that everything is working in unison there has to be a conductor a master clock and that is known as the circadian rhythm so i want to show you this slide that describes the circadian rhythm now it looks rather daunting and that's actually part of what i want to show you is to show you how many things that are going on in the body have to be coordinated i want you to think of let's say disneyland you know that you can go to disneyland in the morning and you can go throughout the day and all of those rides and attractions are running but you know that as soon as disneyland closes down at night and i had a friend that used to work at disneyland there's so many things that happened behind the scenes and after hours to make sure that the park is ready to go the next day the trash has to be taken out things have to be cleaned out it's a new day that's about to happen and the same thing happens in the human body the human body is extremely complex and because of that there are so many processes that are occurring that it's not just one continuous thing there are times of the day where certain things tend to happen and times of the day when other things don't so i wanted to show you here what i'm referring to and just to give you an example of what we talked about with oxidative stress we can see here that melatonin secretion starts at 2100 that's about nine o'clock at night we call that dim light melatonin onset because if you are watching dim light then it's going to basically start to secrete melatonin from the pineal gland but if you notice as we go around this cycle melatonin will stop at approximately 7 30 in the morning it's interesting because around that time cortisol levels start to peak and they go around and finally die out at around the time that melatonin is starting to come on we'll talk more about that cycle but if you just look here you don't need to know this stuff but you can just see for instance that your fastest reaction time is around 15 30 that's about 3 30 in the afternoon we know that your highest alertness is around 10 o'clock in the morning your best coordination is around 2 30 in the afternoon all of these things are happening because there is a master clock that's coordinating all of the smaller clocks to be on at the same time okay dr schulte a couple questions number one you said melatonin secretion starts at about nine pm but i imagine it's variable from person to person and also of course depends on whether or not they're viewing bright light at night and the second question is you mentioned the dim light melatonin onset is it actually the viewing of dim light that stimulates melatonin release or is it just the absence of viewing bright lights that actually stimulates melatonin to be released yes both good questions dim light melatonin onset is kind of a bad name for it because really it's the absence of light that allows the pineal gland to stimulate and produce and secrete melatonin throughout the blood and the human body you're right that it may not be nine o'clock in everybody and that's the problem is this circadian rhythm has to fit onto reality this is a clock that's going on inside your body but the problem can come in is if your clock is not in tune with what reality is on the outside in other words there's a certain part of your body your circadian rhythm that's attuned to when you should be awake and if it's not correlating with when the sun is up you might have some problems so yes the circadian rhythm which is very finely regulated inside the body but the question is is it actually in line with what's happening outside the body what reality is and that's the question you mentioned that it's key that our internal clock our circadian rhythm is uh optimally aligned with reality and that there's all kinds of potential benefits or and consequences to that what are some of the specific things that our circadian rhythm regulates well if you look at this list this is pretty extensive kyle i mean circulating melatonin we know as an antioxidant there's studies that suggest that it can reduce cancer it reduces cortisol production which is what you don't want to have at night which is good it's an antioxidant and it promotes sleep that's just the melatonin aspect but the circadian rhythm also is used in regulation with peripheral clocks the feeding and the fasting rhythms right so you're not typically eating at night you're eating during the day and so those are coordinated we have hormones that go throughout the body like cholecystokinin leptin and ghrelin these are involved with diet these are involved with being hungry and with being satisfied body temperature glucose metabolism the pancreas and you can see some of the other ones there vasopressin which is a blood pressure hormone that determines when your blood pressure should be high and when it should be low obviously you want it lower at night when the body is resting acetylcholine is a very major neurotransmitter cortisol we've talked about already insulin is involved in diabetes adiponectin which is involved with adipose tissue and fat and then of course just overall metabolism regulation which is going to vary depending on the time of day so it's really important that the circadian rhythm is in sync and is well regulated and you asked about consequences there's been a number of studies that have been done both in rodents and in humans that when they apply the dysregulation of the circadian rhythm and rodents we can see problems with body temperature increased fat altered immune system tumor developments and basically just perturbations of the hormonal homeostasis in human beings when they do this prospectively they show that there are problems with insulin regulation leptin and norepinephrine and also increased markers of inflammation and diabetes so there's a lot of problems when you have dysregulation of the circadian rhythm you mentioned leptin what is that well leptin is a hormone that regulates your hunger there's two hormones there there's leptin which makes you feel satisfied and there's ghrelin which increases your need for food you feel more hungry basically and so when you're not sleeping at the correct time when your circadian rhythm is off you're going to feel hungry and probably eat more food if you have too much ghrelin or not enough leptin you're going to also feel hungry and eat more food so there's a problem there when your circadian rhythm is not in sync so again you've mentioned the importance of matching our circadian rhythm with what's going on outside in the world so how how do we do that what are some strategies that allow us to do that effectively well what you have to understand is that the body is hardwired to be able to take information from the environment and to change its internal circadian rhythm so that it's in sync with the environment and this slide here tells exactly how that happens so as you can see here when light hits the eye and specifically goes to the retina and i want to specifically say that we know that light that goes to the retina is hitting rods and cones and those go to neurons which then project back here to the occipital lobe and that's where we actually can understand and visualize and see things what i'm about to talk about is a completely different section of the retina and it does it in a completely different way the first thing you have to understand here is that there is light that we see that we can describe what i'm about to talk to you about is light that comes into the eye that goes to a completely different part of the brain and it's not light that you're conscious of it's light that you're unconscious of and that's important to understand this light that's coming into the eye is not going to rods and cones but instead this thing called intrinsically photosensitive retinal ganglion cells now these are ganglia they are in particularly in the inferior portion of the retina at the back of the eye and that's important to understand because usually light that comes from the superior visual field when it hits the lens is going to be projected down into the inferior retina so this is going to be stuff in the superior visual field it is then projected to something called the suprachiasmatic nucleus now this is the master clock this is the portion of the brain that makes sure that everything is working in sync this is the conductor of that orchestra that i showed you at the beginning when light comes in it's telling the suprachiasmatic nucleus that it is daytime that it is during the day that this must be coming from the sun this is how we are hardwired and because of that there is a specific neuron that shuts down production in the pineal gland of melatonin and so light coming into the eye goes to the intrinsically photosensitive retinal ganglion cells that's a long word there and it gets projected not to where you would actually see consciously you would see light but rather to the suprachiasmatic nucleus which tells it that it's daytime and therefore tells the pineal gland do not make melatonin because melatonin in the blood system is a signal to the cells that it's nighttime and it's time to go to bed and so this is how the system the circadian rhythm understands that it is daytime versus nighttime now there's actually more to this because obviously it's possible for you to be out of sync so the question then becomes how does the brain and the circadian rhythm inside your brain adjust to reality so i want to show you how the circadian rhythm in your brain can be shifted one way or the other depending on the external sources of light so i want you to imagine that you're on a desert island that you have no sort of extrinsic sources of light and you're perfectly aligned you can see here that the knight of the circadian rhythm is actually aligned with night which is reality and also the daytime is perfectly aligned with reality which is day that's the ideal in our situation if we were to for instance expose our eyes to the screen or our iphone or anything like that what could happen is that we would start to expose our eyes to light at a time where we would not normally be experiencing light and so what the circadian rhythm wants to do in that situation is it's thinking that it's still daytime and as a result of that it's going to shift itself over to that to encompass and capture that because it thinks that it's too early and so you can see here very clearly that exposure to light at night after the sun goes down has a tendency to delay your circadian rhythm now that can cause problems as we've talked about before but the biggest problem that you might notice yourself consciously is that even though you're at night here your circadian rhythm is not ready for sleep and so you might actually get the symptom of insomnia and also similarly it's day here at the beginning and you're still in the middle of your sleep and so you might get hypersomnia in the morning and you can see here that it's important to understand that avoiding light especially late in the circadian rhythm as this after the sun has gone down before you go to bed avoiding it can prevent this type of shifting from occurring interestingly also is exposing your eyes to light here in the beginning of the day can help anchor your circadian rhythm and prevent it from sliding later and later because of viewing of light in the late hours but i will say that making sure that you expose your eyes to bright light in the morning is not a substitute for avoiding bright light in the evening okay to summarize if i get good sunlight in the morning that can help anchor my circadian rhythm to reality and then if i avoid a lot of light or screen time in the evening that can help kind of reaffirm to my circadian rhythm that it's time to wind down it's nighttime and time to start stimulating melatonin release do i have that right yeah you actually have it exactly right and i would add a little bit more to that a couple of things that you should be aware of is that if we go back to this master clock picture again you'll notice that light is coming in and it's the inferior portion as we talked about so it's really important to avoid bright light especially high up in your visual field so ceiling lights things of that nature i would say if you had to use lights using lighting on the floor or using lighting low on the wall those night light types of thing would be much better also realize that the peak sensitivity of those intrinsically photosensitive retinal ganglion cells around 460 to 484 nanometers which is basically in the blue section now you may have heard of blue blockers and even programs on your screens and computers that can reduce the amount of blue light because this is the type of light that specifically is going to excite those intrinsically photosensitive retinal ganglion cells but kyle just to be perfectly honest it's any kind of light that's really going to stimulate it it's just this blue light that seems to be the worst at stimulating those ganglion receptors and remember when they do they're going to tell the suprachiasmatic nucleus as we've shown here to shut down melatonin production and the point is that melatonin is the coolant that makes sure that the engine is running smoothly and that antioxidants are kept to a minimum so you really want to have that melatonin production at night and you don't want light shutting it down you mentioned not suppressing melatonin release is key for the antioxidant effect but it also seems key just to initiate sleep right doesn't melatonin have tremendous benefit in initiating sleep for us as well yes it does actually and many people take melatonin as a supplement orally to help with that as well but generally speaking you don't need to have a melatonin supplement to have the onset of sleep and that's because our pineal gland makes its own melatonin and secretes it and it's a message to the body this melatonin goes throughout the entire circulatory system and it tells the cells it's a way of mentioning to them that it's time to go to sleep and melatonin production as you say is a signal for sleep there's a lot on this slide that i want to ask you about and i think it's super interesting that the angle of light not only the intensity of light but the angle of light has an impact on whether our melatonin is released and we feel sleepy and ready for sleep or not and presumably is this because we've evolved as humans to if anything be around a fire at night and that might also explain why the peak sensitivity for blocking melatonin is between 460 and 484 which is that blue light spectrum so in theory low light that's predominantly red light far away from that blue light spectrum should not inhibit that melatonin too much is that right it does seem as though a fire was made specifically or maybe we were made specifically for the fire because if you notice a fire is generally away from the blues and more into the reds and the oranges and it's usually in front of us it's down low and so that's exactly where we would expect to have the least impact in terms of melatonin secretion or not at night so in other words a fire sitting in front of you it's going to be reflecting on the superior retinal ganglion cells where there's not a lot of these intrinsically photosensitive retinal ganglion cells and so the melatonin production should still stay relatively good and also as we mentioned fire is typically red oranges and not the type of thing that we would see with blue light etc interestingly also is at sunset when we see sunset the sun is going down typically the sun is reddish it's orange we're not getting a lot of that blue light and so it's almost like the body is getting ready for sleep melatonin is starting to come on depending on the time of day very interesting dichotomy that we see there with fires versus blue lights dr schwell you mentioned blue blocking glasses there and some people have tried these many people have heard of blue blockers basically what they are is a glass that filters out almost all or all of the blue light spectrum and you mentioned that these aren't a silver bullet but what would be the consequence of wearing these during the day if someone's spending a lot of time at their computer wearing blue blocking glasses would that have what type of effect would that have on someone well because those intrinsically photosensitive retinal ganglion cells have their peak sensitivity in the blue region and because you want to have as much stimulation to those retinal ganglion cells as possible to let the superior cosmetic nucleus know what time of day it is you don't want to be wearing blue blockers during the day and what about at night so i understand now you you gave the analogy of a desert island if i was on a desert island with no electricity that would from a circadian rhythm standpoint that would probably be optimal for aligning my circadian rhythm with reality but that's not the reality we live in sometimes people need to work late they need to be on their screens you know working on their laptop or maybe they they want to watch a show in the evening would there be some benefit to wearing a a blue blocking glass or potentially using a program on your phone that dims some of that blue light spectrum because the intrinsically photosensitive retinal ganglion cells are very sensitive even to non-blue light the best situation is not to view light at all the next best would be if you have to is to wear the blue blocker glasses to at least get the the blue light which is the most efficacious light for these uh sensors out and then the worst case scenario would be to watch it without any kind of blue blockers at all i would just add kyle that if you are gonna have light at night like we've talked about have it more reddish in the warm spectrum of light have it down low and have it as dim as possible that way you can maximize your melatonin secretion and again keep those engines running cool and not overheating with oxidative stress and of course having melatonin secretion for sleep as well so are these intrinsically photosensitive retinal ganglion cells basically the sensors within our eye that sense how much ambient light there is do they have any other purposes yes they do so in addition to projecting to the suprachiasmatic nucleus which regulates the circadian rhythm they also project to another part of the brain which has nothing to do with vision called the perihebenular nucleus and as you can see here it is completely separate from the suprachiasmatic nucleus but it is involved with mood and so this is something that we see a lot of in the wintertime when people become depressed and this is known as sad or seasonal affective disorder this is one of the manifestations of not enough light getting to this area of the brain kyle about five percent of the population get symptoms of seasonal affective disorder and symptoms appear in these patients about 40 percent of the year we typically see it more in females versus males but when they did a meta-analysis of all of these studies that looked at light in these patients about 173 studies that were identified randomized placebo-controlled trials looking at the dsm diagnosis in about 20 studies they found they showed something very interesting that when they were exposed to bright light at about 3000 lux hours so that would be 10 000 lux for about 20 minutes in the morning and they did it for at least four days they were able to show very conclusively that overall with this meta-analysis there was an improvement in the seasonal affective disorder with bright lights so in addition to just stimulating your eyes with bright light in the morning we can talk more about the way that works another way of doing this is something called dawn stimulation you can see here on the chart that increasing light exposure automatically in your bedroom from about zero initially to about two to three hundred lux over a one to two and a half hour period of time can also improve seasonal affective disorder as we can see here again with this meta-analysis where overall there was an effect size of these patients so it's slowly bringing the lights up and there's actually lights that you can program to do this sort of thing i want to demonstrate what one of these dawn simulation lights looks like and dr schwelt never has to use one of these because he lives down in sunny southern california but um you can see it's got a one on it now it's going up to 8 10 so it's got from 1 to 20 for this particular light and you can program this so it simulates dawn over an hour or over 2 hours or whatever you want and this little guy is a light made specifically for seasonal affective disorder i'll turn this on here it's really bright this one gives off 10 000 lux as long as you're within 15 inches of the light source i've experimented with spending 20 minutes or so in the morning working on my computer or reading with this light coming from overhead and again being within 15 inches of it dr schwall are there any other mental or psychiatric conditions that can be potentially treated with light well yes kyle in 2017 this paper was published looking at can proper light therapy affect bipolar depression and this study showed that in 46 patients which were randomized to placebo versus 7000 lux bright white light versus 50 lux dim red placebo light around 12 o'clock to 2 30 in the afternoon 15 minutes per day and then building up to one hour per day by week four you can see here that by week four there was a significant increase in the patients that were in remission from bipolar depression that's a good thing as as the number goes up that was good and you can see that as the amount of light that was given to the patient increased after week four there was a much higher percentage of patients that were in remission who got the 7000 lux bright white light in the afternoon that's really interesting are there any conditions that a dawn simulating light helps with yes actually there was a paper that was published in 2010 that looked at artificial dawn for two weeks 250 lux or 50 lux versus control and what they saw was a significant reduction in sleep inertia in other words it was easier to get up you weren't feeling like you were tired and you wanted to stay in bed in the 50 lux and the 250 lux versus no dawn at all and you can see here that very similar intervention the dawn stimulating light when they did this for 30 minutes 30 minutes prior to waking up and then 20 minutes after waking up compared to a very small amount of light they were able to show that this dawn simulating light improved subjective well-being mood and actually cognitive performance as compared with the dim light and the minimal blue light that they had as controls i would just say though that this artificial light this dawn simulating light is really just a way of capturing what you would normally have if you were to go outside and expose your eyes to bright lights outside early in the morning so all of this is really to show that stimulating your eyes with bright light from the sun is very beneficial you mentioned earlier that not only melatonin but cortisol is key in regulating our circadian rhythm can you tell us more about cortisol so cortisol comes up early in the morning usually around eight or nine o'clock in the morning and then tapers off as it goes around to midnight and cortisol is actually the thing that sets in motion the timing of melatonin about 12 to 14 hours later so if cortisol is coming up at around 8 o'clock in the morning then melatonin is going to be coming up at around nine o'clock at night in a perfectly timed circadian rhythm as we talked about but when you have cortisol levels that are not aligned correctly if your circadian rhythm is off cortisol pulses that are shifted later in the day can be correlated with conditions of anxiety and also depressive disorders also bright light is a strong stimulus for cortisol levels coming up in the morning again another reason why you want to have bright light stimulation early in the morning when you're getting out because that allows the cortisol levels to come up and that's going to time the melatonin levels later in the evening so remember that cortisol is a very important hormone it's a steroid hormone it goes into the cells goes into the nucleus and it controls about 20 of the genome of your dna and so that if you have chronic stress also remember that chronic stress increases cortisol levels above what they should be and that can cause problems on down the road so you want to have enough cortisol you want to have it at the right time and you don't want too much of that cortisol and so again another important reason why you want to have bright light exposure in the morning to anchor the circadian rhythm and to make sure your cortisol levels are coming up at the right time i've heard there's been some research about melatonin being connected with cancer rates can you tell us more about that yeah so the thing that we have to remember is that even a small amount of light can completely shut down melatonin production in the pineal gland and so if melatonin is the antioxidant and the sleep signal that we need if it gets shut down is that going to cause problems we talked earlier that potentially some of the problems are you know related to cancer and so there's been some research on this and it has been associated with an increased risk of cancers specifically breast cancer and specifically the type of breast cancer that is not responsive to hormonal therapy there's been also some other research that has gone into this and the who has classified circadian disruptive shift work as a probable carcinogen because of this connection interestingly in patients who have become blind because of the severing of the optic nerve remember not only is the rods and cones sending neuron axons through the optic nerve but also these intrinsically photosensitive retinal ganglion cells send their axons through the optic nerve and so ostensibly if you were to have these things severed there would never be input to the suprachiasmatic nucleus to shut down melatonin production at that time of the circadian rhythm and what they've actually found in some studies is that there is a reduced cancer risk in totally blind people there was a relative risk of 0.69 meaning that they were 69 as likely to get cancers as people who were not blind and again with these studies we'll go ahead and put links in the description below so you can look at these studies yourself so we spoke earlier about how important it is in the evening once the sun goes down to dim lights if you're going to have lights try to have them below the level of your eye avoiding bright screens if it gets dark pretty early like it does in oregon where i live the first thing i would think of doing is reading more at night and i have an e-reader a lot of people read on their iphone or their tablet so what is the consequence of of doing this and um if we can't use e-readers what should we use yeah so you you can imagine looking at a book using a light bulb reflecting off of a regular book print book versus a an iphone or an ipad or an e-reader what would be the difference you would think that they would be about the same you know there was a paper that was published in 2015 that looked at that very question as you can see here what they measured was the irradiance of the e-book versus the print book and you can see here we have irradiance on the y-axis and we have it broken down into wavelengths what we have here up top is the e-book and you can see clearly that especially in the blue range there's quite a lot of irradiance coming out at that point what you probably might have a hard time seeing is because it's so low is looking at a print book in regular lights and you can see clearly that there's a huge difference in the irradiance between the e-book and the regular print book so again it would be better for you to read at night using a regular print book than reading off of your iphone ipad or an e-reader what is spectral irradiance and the other question i have is did it matter in the study whether the light source for those using a regular book not an e-reader was led light or incandescent or something else or what did they use in the study so in the study they simply said very dim light so they didn't mention if it was an led light or an incandescent bulb but in terms of irradiance irradiance as you can see there from the units are micro watts per square centimeter so that's basically how much energy there is and it's very similar to what we would say lux would be okay so this study established that there's more light energy significantly more coming towards the eye from an e-reader as opposed to just a regular book with with dimly dimly lit room did that have any consequence on someone's sleep or their health well if you look at sleep latency which is the time it takes for somebody to fall asleep you'll see that it was much longer in those who were watching the ebook than those who were reading the book in dim light in the study it also showed that those subjects that were reading with the ebook felt more sleepy the next day when they got up in other words they had more sleep inertia okay dr schwell to summarize can you give some specific recommendations for optimal light viewing and avoiding light in the evening yeah so let's summarize exactly what the recommendations are number one in the morning view sunlight as soon after waking up as possible ideally before nine o'clock in the morning look there's nothing better than going outside as the sun is coming up there is much more light outside than you're ever going to be able to generate insight but if you have an issue where the sun is not up where it's very cloudy where you live you can aim for about 10 000 lux spend about 20 to 30 minutes a day in the morning you want to be anywhere between 11 and 15 inches from the light box so that's one option but again nothing beats actually going outside remember when we talked about lux that on a bright sunny day it's about a hundred thousand luck so you can get that very very quickly remember that the photoreceptors in the retina in the morning are not very sensitive so you need to have very bright light to activate it but it's kind of integrated over time so if it's not very bright you have to spend a longer amount of time if it's very bright then you don't have to spend much time at all if you're in very bright light 30 seconds may be all that you need if it's a hundred thousand lux on a cloudy winter day like we were just talking about it could take up to 30 minutes but again making sure that you're getting your eyes looking at bright light in the morning you want to avoid sunglasses you want to avoid windows and we'll talk a little bit more about this but especially the low e glass that's very effective at filtering out infrared light you don't want windshields that doesn't really count you want to get outside and have nothing between you and the light source again avoiding blue blockers we talked about how blue light stimulation is really key at that time of the day so make sure that you're getting as much stimulation as possible in terms of what you should do in the evening time after the sun goes down is to limit as much light as possible after sunset you want to have any kind of light that you have as low as possible you want to have it as red as possible and you want to have it as dim as possible so that you can have the benefit of melatonin secretion from the pineal gland when the time is right remember what we said that intrinsically photosensitive retinal ganglion cells are more activated by blue light so if you have no choice if you have to do something it's better to make sure that the blue light aspect is reduced either by programming it into the computer or by wearing blue blockers glasses that really is the two aspects of this portion of the talk where we talk about how light interacts with the human body in a circadian rhythm way what should you do in the morning number one sunlight before nine o'clock anywhere between 30 seconds and 30 minutes depending on how much sun there is because remember that these intrinsically photosensitive retinal ganglion cells are not very sensitive in the morning so it takes time but the good news is is that there's integration which means that the more time you spend the more activated they're going to be so if there's bright sun it might only take 30 seconds but if it's cloudy if it's a dim day if you're getting up early before the sun comes up it might take as much as 30 minutes so because of that you don't want to be wearing sunglasses you definitely don't want to be wearing blue blockers because blue light is really good at this point you don't want to be behind a window or a windshield it's okay to have glasses or contacts because if you do if you wear the sunglasses if you're behind a window or the windshield it's going to take a lot longer to get the stimulation that you're going to need otherwise the other option is is you do it inside and you get this 10 000 plus lamp that has 10 000 lux and spending about 20 to 30 minutes in the morning about 11 to 15 inches away from the light box is going to be what you need to really anchor and to get the light stimulation that you need to get the cortisol secretion that you need and also the melatonin timing and to really set the circadian rhythm right now to keep that going what are you going to do in the evening really it's this basic understanding that photons light that's going to the retina is going to shut down melatonin production you really want to have the lights as dim as possible if you do have lights have them as low down in your environment as possible because we talked about that light down low around the floor lower part of the walls is not going to stimulate the super suprachiasmatic nucleus as much and therefore shut down melatonin production and then again if you have it more towards the red aspect of the spectrum yellowish reddish that type of thing then you're also not going to shut down melatonin production think about fire it's low down it's dimmer and it is redder those are the types of things that could be beneficial for you at night i would have thought that sitting in front of a window with full sunlight coming at me through the window would be almost as good as being outside or if i'm driving in my car you know my way to work or whatever it may be if i'm driving right at the sunlight it seems like that would suffice but you're saying that there is a huge difference between actually being outside viewing light and being behind a window do i have that right yes you do have that right so if we look here at a family living room ostensibly with windows you're talking about 50 lux in terms of intensity versus an overcast day which you would think about the same that's 20 times higher in intensity at a thousand and that's just an overcast day so going full daylight and even direct sunlight much much higher we really have a poor sense because our pupils adjust and our eyes adjust to light when we go inside versus outside outside there is tremendously more lux in terms of light than there is inside and i'll add that if anyone wants to play around with how much lux is in their environment whether it's outside or inside there are a variety of apps for your smartphone of choice some of them involve actually creating getting a white piece of paper and creating a filter for your light sensor on your phone but you can measure the amount of lux in your environment at home so you can get a sense of where you are so this is the second part of our talk where we talk about how light interacts with our bodies and the mitochondria that i refer to at the beginning this is really interesting it was mind-blowing when i first learned about it and i imagine that most of you out there probably have not heard this before so as we talked about the mitochondria are the portions of the cell which are the powerhouses they make energy and they make atp similarly to how an engine in a car makes locomotion but the problem is with locomotion heat is generated around the engine and that heat can stand to shut down the engine if it's not dealt with in an appropriate way with a cooling system same thing with the mitochondria the byproduct of making energy is oxidative stress and as we talked about before at the beginning let's review a little bit the mitochondria if they're not cooled down to use the analogy oxidative stress can happen and oxidative stress can lead to less optimal health inflammation cancer dementia diabetes and even learning disabilities and as we'll talk about later it's been implicated with 19 mortality so how does the body deal with this as we talked about earlier we know that at night melatonin is secreted from the pineal gland normally if the person is not being exposed to light and this melatonin is actively secreted and actively taken up into the cell and then it goes into the mitochondria where it is the major antioxidant actually is the one that controls glutathione it's twice as potent as vitamin e but the question is is while this is happening at night that's great but what happens during the day when more energy is needed and essentially these mitochondria are revving up at higher rpms what happens then well scientists are now discovering that infrared radiation from the sun actually directly stimulates the mitochondria to produce melatonin on-site where the oxidative stress is occurring now this is not from eating melatonin or taking a supplement this is actually from the sun itself penetrating down into the tissue stimulating the mitochondria to produce melatonin there's this very interesting paper that was published by scott zimmerman and russell ryder one of them a professor and the other one a light engineer that described this and i would highly recommend looking at this article we'll put a link in the description below but what they said in this article and these are the highlights is that melatonin we know is a potent antioxidant and that it's actually produced within the mitochondria in response to sunlight and provides targeted protection of the mitochondria from reactive oxygen species it's also protective against a wide range of diseases that are identified with mitochondrial dysfunction including cancers neurodegenerative diseases cardiovascular disease and also diabetes and it may have a role in the prevention of diabetes alzheimer's disease parkinson's disease and even as we'll talk about covid19 so let's take a little bit more closer look at what's going on in the mitochondria and why this is happening so let's talk about what's going on here you have to understand that all of the cells in your body have things called mitochondria and the mitochondria are these powerhouses or power plants inside the cell that make energy and the product of that metabolism is something called atp and atp is the molecule of energy for the cell so let's take a look at the mitochondria in a little bit more detail so if we look at mitochondria there's an outer membrane and there's an inner membrane the center we call the matrix and this space around it we call the inter membrane space let's zoom in a little bit and take a better look at what's going on there here we see the inter membrane space and here we see the matrix in the matrix we have something called krebs cycle krebs cycle is where carbohydrates proteins and fats are metabolized and they enter into krebs cycle at various different pathways and they come from obviously the outside of the cell the major byproduct of krebs cycle is something called n a d h in addition to nadh there's a small amount of atp and gtp and other reducing agents but the major product of krebs cycle and the metabolism of carbohydrates proteins and fats is to make nadh now nadh is a way of packaging very powerfully reduced electrons so what's interesting now is how the mitochondria take these very reduced electrons and convert them into energy and that's done with something called the electron transport chain the electron transport chain and the electron transport chain is basically a series of drops almost like a dam that goes through this electron transport chain and at every step along this way the energy from those reduced electrons from the nadh is coupled with a pump that pumps protons out into the inter membrane space so that the amount of protons in the inner membrane space start to increase and this occurs successively as the electrons are passed down step by step by step until finally all of the energy is extracted from these electrons and the final electron acceptor is something that we all need and that's oxygen and this is the reason why we need oxygen when we breathe is we need an acceptor of those electrons so this is where oxygen is required now this is very important for you to understand finally at the very end of this electron transport chain there's an enzyme known as cytochrome c oxidase or cco for short that takes this oxygen molecule and makes a water molecule out of it by passing on those electrons to this oxygen molecule the problem is is that when this stuff starts to go and these wheels start to turn if you will and these electrons start to be passed down the chain it's not perfect and sometimes you can have these electrons getting caught up with other oxygen molecules and something called reactive oxygen species being made the most common one here being superoxide but there are other ones as well such as hydrogen peroxide and also hydroxy radicals all of these are very dangerous substrates that can interact with the proteins around them and can cause severe damage and the more damage they cause the more likely there is to be more reactive oxygen species made so it's very important that if and when these reactive oxygen species are made as a result of metabolism and this electron transport chain that they get mopped up more about that in just a second but first let's go back and talk a little bit about what happens with all these protons so these protons start to build up and then what occurs is finally there is a protein here that sits in the inner membrane space known as the f atp ace and simply what happens here is the protons go down their concentration gradient back into the matrix and what you have is a dp becoming atp as these protons go down their electron gradient and here you have the product of this whole thing which is atp which is again the high energy product of this entire process of metabolism so you go from having carbohydrates proteins and fats into making atp in the process of this you do need to use up oxygen more importantly for our discussion today is you can't help but make reactive oxygen species well the way that the body has of mopping this up or making sure that these things go away is through melatonin so there is of course melatonin outside the mitochondria outside the cell that can come in and mop up these things very quickly because melatonin is a very powerful antioxidant but now we're finding out that specifically this last enzyme that we talked about cytochrome c oxidase which takes this oxygen molecule and makes it into water and makes this process go well when this enzyme cytochrome c oxidase is excited with a certain wavelength of light specifically infrared light it actually increases melatonin production inside of the mitochondria that's right melatonin is produced inside the mitochondria as a result of the activation of this electron transport chain which can then neutralize the product of the electron transport chain which is not only water but in certain cases oxygen as we mentioned mixes with these electrons inadvertently making these reactive oxygen species now these reactive oxygen species as we mentioned are very dangerous and they have to be dealt with on site because they react very quickly to products around them and can oxidize them and damage them and as these things become damaged they cause more oxidative stress and more mistakes and more superoxides and hydroxyl peroxides and hydroxy radicals and there are certain diseases associated with this as we mentioned alzheimer's disease and parkinson's these are all situations where the mitochondria are not acting appropriately and we can talk about a number of other diseases that are also in line with this so what you're saying dr schwalt is infrared radiation from the sun stimulates something called cytochrome c oxidase and that in turn tells the mitochondria in all of our cells to stimulate melatonin production in fact this is not very well known because this production of melatonin kyle is happening inside the mitochondria it's taken us a lot of time and energy and technology to be able to detect those that type of level where we first detected melatonin was in the blood and that's the that's the backup plan at night but what we're starting to find out is that melatonin production in the mitochondria is actually the front line cooling system for the mitochondria as you can see here on this slide less than five percent of the body's melatonin is produced in the pineal gland and greater than 95 of the body's melatonin is produced on site in the mitochondria this is a quote from zimmerman and writer he says it has now been shown that the mitochondria produce melatonin in many cells in quantities which are orders of magnitude higher than that produced in the pineal gland this subcellular melatonin does not necessarily fluctuate with our circadian clock or release into the circulation system but instead has been proposed to be consumed locally in the mitochondria in response to free radical density within each cell in particular in response to near infrared exposure there's more to this quote so bear with me i'm going to go on here based on an optical and biological review of the literature it is proposed that the near infrared portion of natural sunlight and we'll define that stimulates an excess of antioxidants like melatonin in each of our healthy cells and that the cumulative effect of this antioxidant reservoir is to enhance the body's ability to rapidly and locally deal with changing conditions throughout the day in this approach the role of the circulatory melatonin produced by the pineal gland is to provide an efficient method of delivering supplemental melatonin during periods of low cellular activity that would be at night and solar stimulus to damaged or aging cells in both diurnal and nocturnal animals while circulatory melatonin may be the hormone of darkness in other words the pineal gland at night provided that there's no light hitting the retina however subcellular melatonin that is intra mitochondrial melatonin may be the hormone of daylight in other words this intra mitochondrial melatonin is a result of the person going out into the sunlight specifically infrared radiation question dr schwell subcellular melatonin that is produced within the mitochondria of our cells during the day does that have any effect on us feeling sleepy not at all so this is inside the mitochondrion this is the reason why to get this effect you really can't take oral supplementation because oral supplementation is going to go into the circulatory system eventually and that's going to send off a whole bunch of signals to cells to tell them that it's time to go to sleep this intra mitochondrial melatonin is doing the job inside the cell and it has nothing to do with sleep at all and to clarify the primary way to get that is from natural sunlight that is correct and we'll talk about other ways you could potentially get that as well so you mentioned infrared light coming from the sun and specifically near infrared can we go back to that um spectrum chart that you had that showed all the sun's energy and can you explain near infrared in more detail yes so near infrared is just a aspect of the entire spectrum of light here we see the solar spectrum and we're specifically looking at near infrared radiation that is the part from 760 nanometers to 1400 nanometers and you cannot see this how you experience near infrared radiation or light from the sun is a feeling of warmth and that is because this type of light from the sun can penetrate deep into the epidermis the dermis and even the subcutaneous tissue depending on the wavelength and it's perceived as heat because the transfer of this energy actually stimulates the heat receptors in our skin and that is how it is felt you'll often feel this right if you're in the sun and your back is to the sun and you've got a shirt on you'll feel that warmth on the back that is infrared radiation speaking to you why is it able to penetrate through clothes it's actually able to penetrate quite deeply kyle have you ever pulled up to a stop sign and a bunch of teenagers in a in a car pull up to you and they turn on their their radio what do you hear all you're hearing is the boom boom boom right that's the low frequency sounds that's because low frequency or long wavelength energy can penetrate through things fairly easily and so that sound is penetrating their car going across into your car and it's vibrating your steering wheel and that's because this type of light this infrared and specifically the near infrared energy can penetrate very well through the atmosphere it can penetrate very well all the way down through your clothes and into your skin and actually deep into your body and it's able to have the effect that it has on many of the cells in your body as a result so the purpose of this slide is to demonstrate that the majority of the energy coming from the sun and hitting the earth is in the infrared spectrum here we have infrared on the right side of this black bar we have the visible spectrum here and we have ultraviolet over here on the left and as you can see if we look at the red envelope here we'll see that this is the amount of energy that's hitting the earth in the visible spectrum but all of this red over here and specifically right up to about 1400 all of this is the amount of energy that is coming through the atmosphere hitting the earth in the infrared spectrum so we're dealing with a large amount of energy if we look at that energy as it hits the skin notice that wavelengths that are longer tend to penetrate more deeply the interesting thing about this is that infrared which is out here or specifically near infrared can actually penetrate down it is estimated depending on which study you look at anywhere from one centimeter up to eight centimeters and as you know one centimeter is twice five millimeters so you can see how deep this could actually go so does wearing sunscreen block infrared radiation into our skin well sunscreen and sunblock is very good at blocking ultraviolet light it is not very good at all and actually has really no effect on the ability of the sun to radiate infrared and through the skin and you mentioned this earlier but clothing if i'm wearing a couple layers of clothing or maybe even a jacket can i still get infrared radiation penetrating into my skin well it depends on how much you're wearing so if it's a very large jacket yes especially a thermal jacket because the way we experience heat infrared is not going to penetrate that very well but you can put on clothes that would prevent ultraviolet light from causing sunburns and things of that nature but it would not prevent the infrared radiation from penetrating down into your skin so it was a good rule of thumb that if i can feel the warmth from the sun on my skin i'm probably receiving infrared radiation into my skin yes that would be a very good indication so if we look at the paper from zimmerman and ryder what they demonstrated here is that regardless of whether or not the skin is melanin rich or not you can see here that this infrared light was able to penetrate down up to eight centimeters into the skin some is reflected but the point here is is that infrared radiation can penetrate up to eight centimeters according to some of their studies and that is a significant amount in terms of depth and the amount of tissue that infrared radiation can actually affect if we look at this picture here of a hand in visible light visible light reflects off the surface of the skin but near infrared light at in this case 810 nanometers penetrates down deep enough that it actually shows where the veins are under the surface and this is actually used in the clinical setting to help nurses find veins what's going on here is that the veins and the blood are absorbing the light and not reflecting it back and that's how you're able to see these veins that are beneath the surface what they did in their study is they looked at the number of cells totally in the human body with time and you can see here that as a child grows the number of cells in their body increases in terms of the number of cells that near infrared can reach because it penetrates so deeply they were able to show that there is a large amount of cells in the human body that is accessible to near infrared radiation that as opposed to ultraviolet and visible spectrum which is down here at the bottom so near infrared light even though we can't see it can penetrate very deeply and it affects a number of our cells in our body of course as we grow in girth as we become more obese for instance the number of cells that are not able to be reached by near infrared radiation would become more and more there is a physics of the near infrared radiation that has to be taken into consideration what was very interesting to me was that near infrared radiation could even penetrate bone and what they showed here very elegantly was that near infrared radiation can actually penetrate bone and that the cerebral spinal fluid that surrounds the brain would diffuse the near infrared radiation and would actually cause the sulci and the gyri these are sort of the dips and the crevasses in the brain to trap that near infrared radiation and to reflect it down deep into these caverns so that the gray matter on the surface of the brain could be exposed to near infrared radiation dr schwell did i hear you right that sunlight can penetrate bone yes kyle i too was a little incredulous i will put in the description below an article that actually demonstrates that sunlight can penetrate through the skull but i remembered back in addition to when i was taking a physical examination course in medical school and what they showed and what you'll see here on the screen is a couple of screenshots from a youtube video demonstrating the practice of trans illumination this is where on physical exam you try to see whether or not the sinuses are filled with mucus or if they're empty and open like they should be in this case here on the top left the examiner is shining visible spectrum light not near infrared but visible into the frontal sinus and you can see that it illuminates here and you're able to see that it is completely clear and that tells you if you look down here that is the bone that that light is shining through and that tells you that the sinuses are clear here's another one here over on the right hand side except here the examiner is shining light on the maxillary sinus and it's illuminating and you can see clearly here inside the mouth if you look up through the roof of the mouth you're looking through the maxillary bone and you can see that it is also trans illuminating so if visible light can go through bone then you know that near infrared which has a better propensity to travel through objects can do it as well so would i need to be actually out in the sun to get near infrared radiation no in fact kyle what this figure shows is that the light that comes from the sun is very rich in near-infrared radiation what's even richer in near-infrared radiation is the light that reflects off of the green leaves and the trees and the grass you see that most blue green and red materials have a very high near infrared reflectance and so actually what's coming to our eyes is light especially if you're surrounded by greenery that is very rich specifically in near infrared radiation so that when we look at the light that's actually coming to the eyes over 90 percent of that light that's entering the eye isn't even doing so through the pupil it's actually going around it because it's able to penetrate through this near infrared radiation not only the eye but also the rest of the body so that what we're seeing is light that is very rich in near infrared radiation and you actually don't even need to be into the sun so being outside in green spaces is a good place to be from a near infrared radiation standpoint that's exactly correct cal kyle take a look at these near infrared photographs you'll see here that it's exactly as i'm talking about you can see here the leaves the grass the plants they're all bright white almost like they have snow on them and that's because they highly reflect near infrared light so well here's a picture in central park and you can see that the buildings are basically black because there's no reflectance there of near infrared radiation but you can see that the leaves and the trees are highly reflective of near infrared radiation and we're not in the sun here at this point so that is very interesting to me because there's a lot of research kyle that shows that there are health benefits when people are living in green spaces as opposed to concrete jungles this is a paper that was published in environmental research this was back in 2018 not too long ago the title is the health benefits of the great outdoors a systematic review and meta-analysis of green space exposure and health outcomes they said quote we found that spending time in or living close to natural green spaces is associated with a diverse and significant health benefits it reduces the risk of type 2 diabetes cardiovascular disease premature death and preterm birth and increases sleep duration people living closer to nature also had reduced diastolic blood pressure heart rate and stress in fact one of the really interesting things we found is that exposure to green spaces significantly reduces people's levels of salivary cortisol a physiological marker of stress kyle did you notice here that these are the same things that we talked about were the result of mitochondrial dysfunction and we know now that green spaces are very good at reflecting near infrared radiation take a look at this meta-analysis you can see when they looked at all of these studies this diamond here at the bottom means that when they looked at all of the studies and took the average of the results because it did not touch this zero line right here confirming that there was benefit for a subject of this study to be living in green spaces so this sounds like a really interesting theory but do we actually have evidence that near infrared impacts our mitochondria at the cellular level so let's take a look at this evidence this was published in 2016 and what they did here was they took a laser at 1064 nanometers perfectly within the near infrared spectrum and when they applied it to the skin and measured the concentration of cytochrome c oxidase you can see that compared to the blue controls the red laser increased cytochrome c oxidase levels until they turned off the laser and then you could see that it went down so clearly cytochrome c oxidase in the mitochondria is reacting to this infrared laser what they also noticed in the same area of the body was that oxygenated hemoglobin increased as well so in other words what we're seeing here is that the amount of blood supply going to this area increased and as we'll see later the predicate of this is increased nitric oxide so nitric oxide is a vasodilator it's also been implicated in antioxidant systems and basically what we're seeing is when you have this type of radiation near infrared radiation there is an excitation of cytochrome c oxidase that increases the amount of melatonin production and we know that because of chemical studies that have shown the increase in melatonin relative to the enzyme that produces it and also from serotonin where it comes from in the mitochondria also causing vasodilation more blood coming to that area and improved oxygenation to that tissue more on those ends you can see here that a paper that was published in 2017 titled near infrared light stimulates release of an endothelium dependent vasodilator and rescues vascular dysfunction in a diabetes model you can see here that light at 670 nanometers not only improved secretion of nitric oxide but also cause smooth muscle relaxation this is what they say in the article in conclusion 670 nanometer light energy produces acute increases in vessel diameter at physiological pressures through the release of a vasodilator from the endothelium in vitro experiments identify and support the direct actions of light energy on cultured endothelial cells to produce nitric oxide independently from nitric oxide enzyme activity we anticipate under pathological conditions of nitric oxide depletion light energy should be considered a viable means for increasing nitric oxide as evidenced by the significant stimulation of dilation in diabetic vessels thus the acute increases in dilation observed by light energy suggests that it can provide an effective non-invasive source for nitric oxide delivery there have been many studies over a number of years enumerating the benefits of natural sunlight we now know that infrared radiation of course is part of natural sunlight there have been many people that have enumerated the benefits of natural sunlight we have codes now in schools that specifically delineate how much light comes through the windows and back then when they were making up these codes those types of windows did not block infrared radiation so it may be the reason why there was improved outcomes even in schools you can see here in this table there are a number of benefits with natural daylighting as it says on students there's been also a number of specific studies that looked at sunshine this is a systematic review of sun exposure in type 2 diabetes and their outcomes here they looked at 11 different papers that evaluated sun exposure on type 2 diabetes and you can see here that a number of outcomes the highest evidence in this case was moderate and it showed that there was a reduction in association with diabetes with direct sunlight exposure there was another study that was done looking at two different cities in europe one was in the netherlands the other was in england and what they did was very elegant they took a lot of blood tests from these patients and they were able using weather reports to look back over the last seven days to see if there was a lot of sunlight during those past seven days before the blood was given of course it was a very large sample and they were able to see if there was statistical significance between when blood samples were given when it was very cloudy versus when blood samples were given when it was very sunny just before those samples were delivered so as you can see here over 13 000 subjects in the study and what they showed here is after doing the model adjusting for age sex and percent body fat and also season of the year and also outdoor temperature to make sure that they corrected for all those they were able to show that when the percentage of hours of sunlight in the last seven days got less and less and less there was worsening in glucose metabolism and also in lipid metabolism in those subjects so let's talk a little bit about the actual amount of damage that light can do we've talked about all the benefits of light and we haven't really talked about the damage that light can do now what you see here is a spectrum of light going from the ultraviolet here on the left hand side and then the visible spectrum here with infrared going in this direction as you can see on this graph which is graphing basically the amount of radicals that are manufactured so this is basically a graph of oxidative stress from light in the different categories and you can see here that ultraviolet a is very adept at creating reactive oxygen species and oxidative damage uvb also being somewhat high but not as much and you can see that as we go down in energy in terms of light the amount of oxidative stress the amount of damage is much much less the type of light that you want to avoid is ultraviolet radiation not so much infrared it does not cause as much damage and that's important when we're understanding about when we're going to go out into the sun what do we do about the concerns of melanoma and skin cancer and those sorts of things well it's interesting because here was a study that was done almost a thousand cases of melanoma looked at 513 in the population and 174 sibling controls that were recruited in england and they looked to see what was protective in the relationship between sun exposure and melanoma risk and what they found was very interesting they said quote overall the clearest relationship between reported sun exposure and risk was for average weekend sun exposure in warmer months which was protective in other words if you had weekend sun exposure that reduced your risk of melanoma in these subjects they say serum vitamin d levels were strongly associated with an increased weekend and holiday sun exposure there's no surprise there the more you're out in the sun the more vitamin d you're going to be making from the ultraviolet b radiation what about the risk factors for dying from melanoma this was a study that was published back in 2005 and they looked at what things were associated with increased death in melanoma and what things were associated with a decreased death rate in melanoma and you can see that things that were associated with the increased death risk was melanoma thickness mitosis ulceration and head and neck placement so mitosis is when you're seeing the cell divide under the microscope things that were associated with decreased death was actually things that are associated with being in the sun so sunburn was actually associated with a decreased death high intermittent sun exposure was decreased something called solar elastosis that's kind of the damage that you have to your skin if you're out in the sun for too long was actually associated with a decreased death rate i'm not saying that going out into the sun you're going to be fighting never get melanoma i want you to listen to your dermatologist but remember that near infrared radiation the thing that stimulates melatonin production in the mitochondria can penetrate through clothes and so you don't need to go out into the sun directly you don't need to be going out and sunbathing without protection it can penetrate through clothes it can penetrate through sunscreen but just to say you don't have to be afraid of going outside even when the sun is out you can do this and remember that the green leaves reflect a lot of that near infrared radiation here is a study that was done titled avoidance of sun exposure is a risk factor for all cause mortality results from the melanoma in southern sweden cohort this was a very large study about 30 000 women selected at random 35 to 64 years of age in southern sweden and they were followed prospectively for 20 years and there was about 2 500 deaths over those 20 years and they asked about did they go to the sun tanning salon or were they sunbathing and this is what they showed in the data they showed that those that had avoided sun exposure they had sun avoiding behavior their survival rate was this line here at the bottom whereas those that had the most active sun exposure were those here at the top so this is a large study and a very large and long follow-up most swedes of course are fair-skinned and so this can be something that's applicable to a population that's at risk for melanoma that was really interesting to see that graph with uva and uvb and the amount of oxidative stress that those portions of the light spectrum cause relative to infrared and most sunscreens that people buy these days are broad spectrum sunscreens meaning they help block out both uva and uvb but i also want to ask about you know you mentioned melanoma but there's other skin cancers out there there's basal cell carcinomas and there's squamous cell carcinomas they're not as deadly as melanoma typically but um what are your thoughts on you know people that are concerned about all types of skin cancer and want to stay out of the sun also because they want to they don't want wrinkles you know a lot of people are want to avoid the sun for those reasons so what what's a strategy they can use to still get infrared radiation so i too am also very conscious of sun exposure i mean i i i'm thinning a little bit here on the top so i wear a hat so it protects me from the ultraviolet radiation from the sun and obviously wearing clothes shirts things of that nature can do the same but the key here is that infrared radiation can penetrate through those layers of clothing so i can still feel the warmth of the sun on my head even though i'm wearing a cap and so yeah basal cell carcinoma squamous cell carcinoma even sun damage actinic keratosis these things are related to the oxidative stress that is occurring from that particular portion of the spectrum of light which is in the ultraviolet spectrum and that can be mitigated by making sure you're wearing sunscreen that you're covering up but you can still go out even though you're covering up into the outside and get that infrared radiation because it will penetrate those protective barriers and if you forgot your hat or you don't have a way to cover your skin or you forgot your sunscreen can you still be in the shade and benefit from near-infrared absolutely so remember that the sun is shining down on these green leaves these plants the grass which are highly reflective of near infrared radiation so even though you're not in the sun you could be in the shade you're still getting the benefits of that near infrared radiation that's hitting you even though you're not in direct sunlight here's a paper that was done looking at the interdependence and contributions of sun exposure and vitamin d to mri measures in multiple sclerosis now i found this very interesting because scientists have known for a long time that multiple sclerosis has a higher incidence at higher latitudes so in conclusion the results from our cross-sectional study suggest that sun exposure could have an effect on brain volume in multiple sclerosis now remember we talked about how infrared radiation can penetrate the skull and actually can bathe the cerebral spinal fluid in near infrared radiation and be trapped down deep into those sulci where the gray matter is what they found here was that increased sun exposure seemed to improve the amount of gray matter and also brain mass and it was dissociated from the increased vitamin d levels as a result from that sun exposure let's take a look at this graph here i found it very interesting here we have the multiple sclerosis patients up on top and here we have the controls on the bottom and what they did was they divided sun exposure into quartiles so they had the people with the highest 25 percent of sun exposure the third highest the second highest and then the lowest in all of these categories and what they measured here in the first graph was the gray matter volume in other words how much gray matter was there on the mri and you can see a very definitive positive association in multiple sclerosis patients the other thing that they looked at over here on the right side was the whole brain volume so did the whole brain volume go up and you can see clearly that there was also an increase in whole brain volume with increased sun exposure in the controls it was not as dramatic but you can still see that there was a positive correlation whole brain matter not so much maybe a slight amount but remember this is gray matter here on the left and it's the gray matter that's on the outside of the brain and is easily accessible to potential near infrared radiation since we're still in this pandemic dealing with covid19 can any of these health benefits that you've described from infrared radiation benefit us with regard to coba 19. so medcram viewers will know that back in may of 2020 we talked about oxidative stress associated with covet 19 infection and we said at the time that angiotensin ii or at2 which is a pro-oxidant is converted to angiotensin 1-7 which is an antioxidant by the ace ii enzyme which is also receptor and that's the issue with sars cov2 infection because ace2 is not just a receptor for the spike protein it's also an enzyme which is keeping the oxidative stress low in the cell as we said angiotensin ii is a pro-oxidant and so it's going to lead to a lot of reactive oxygen species however at17 is an antioxidant it's going to suppress reactive oxygen species which is good that's what we want to do the problem is is that when the virus infects binds to that ace2 receptor it knocks out that enzyme and so instead of angiotensin ii going down and angiotensin 1-7 going up we have the opposite occur and so what we have is angiotensin ii going up angiotensin 1-7 going down and not only that but the virus itself attracts white blood cells which also has oxidative stress as we talked about earlier and so all of these things lead to an increased amount of reactive oxygen species so if you think about this going back to the analogy of the engine imagine that your antioxidant system isn't working very well your cooling system is not working very well and so as you're driving along your engine is running a little hot which is not good and then all of a sudden what happens is you hit this hill which is called coven 19 and as you're going up the hill that's enough to cause your engine to fall over just the edge where now it's overheating steam is coming out of the engine and you're pulling over to the side of the road that's the issue with covet 19 it's taking patients who have high oxidative stress levels already because they're not optimized and it's causing them to go over the edge so we've talked about this this is why patients are coming into the hospital because this reactive oxygen species are damaging the endothelial cells which line the blood vessels that causes micro clots to occur that leads to hypoxemia and increased oxygen levels the solution of course is having melatonin to cool down that engine melatonin that comes intravenously from the pineal gland and goes into the cells to reduce the oxidative stress melatonin which is coming from the sun through near infrared radiation if you're getting these things you're actually benefiting and you're less likely to run into the consequences of coven 19. here's a paper kyle that was published last month 60 patients admitted to the hospital and they measured the levels of glutathione which is a antioxidant in the cell they looked at tbars which is basically a measure of oxidative stress and they also looked at something called f2 isoprostane which is a marker of oxidative damage and this is really interesting i want to make sure that people understand this so here we're looking at intracellular reduced glutathione so this is an antioxidant first of all i want you to notice that in the control subjects which are in blue that as we get older here's the 21 to 40 the 41 to 60 and the 60 year plus notice that these levels are going down so that's important to understand that as you get older your antioxidant system gets worse kind of like a car right as the car gets older it's more likely to overheat but notice that in the covid patients there was a significant drop especially in the younger there was a significant drop in the measure of intracellular antioxidants now remember what is it that regulates glutathione we already said it it's melatonin melatonin is the product that increases glutathione inside the cell so when we looked at oxidative stress and that's plasma tbars notice the same thing as we go older in the control groups the amount of oxidative stress went up but even more so with those in the covet group so again increased oxidative stress with coven 19 infection finally when we look at the measurements of damage with f2 isoprostane we're seeing here consistently across the board regardless of the age group that coveted patients had higher levels of oxidative damage it's very clear if you look at the data this is not controversial in any way shape or form that we have seen over and over again that people with high vitamin d levels as you can see here in this study of 185 patients people with high vitamin d levels or higher vitamin d levels had better survival probability in covin 19 and those with low vitamin d levels had lower survival we thought that maybe because vitamin d levels were higher in those people that survived that by giving vitamin d we could actually improve their outcomes and for sure in some studies there has been a modest improvement in survival when we gave vitamin d to patients who are in the hospital or even before and there's many studies that show that chronic vitamin d supplementation can help reduce some of these acute chest infections but what i'm believing more and more now kyle is that vitamin d yes can be used but it's also a marker of sunlight exposure and therefore infrared radiation and so it's possible that by seeing high vitamin d levels we're seeing the effects of infrared radiation at the mitochondrial level and the antioxidant level i'm beginning to understand that it may be a mistake to think in other words that if you have your vitamin d supplementation that you don't need to go outside and get infrared radiation i think that would be a mistake if we thought that and one of the reasons why i believe that more and more now is because of this study which was published in the british journal of dermatology and it was conducted by researchers at the university of edinburgh and what they basically did was they looked at the united states and they cut out the portion of the united states during last winter in the winter of 2020 where there would be enough vitamin d production if you went out into the sun so they cut that portion out they only looked at the portion of the united states where there wasn't enough sunlight to make any significant vitamin d and even in that portion so this portion up here they were able to show that increasing levels of sunlight led to decreasing covet 19 mortality when they figured that out they went ahead and prospectively applied it to the country of england and also to the country of italy and they found very similar results that as sunshine levels went up further in the south they found that mortality levels went down same thing here in italy so what they've decided was that something was in the sunlight other than vitamin d that was causing a decrease in mortality in conclusion this study is observational and therefore any causal interpretation needs to be taken with caution granted there's other factors that could have played into this however they say if the relationship identified proves to be causal it suggests that optimizing sun exposure may be a possible public health intervention given that the effect appears to be completely independent of a vitamin d pathway it suggests possible new covet 19 therapies now i wanted to show you that this idea of exposing people to sunlight when they are sick is not a new idea i was able to go back and research what people thought about sunlight and many of you in our audience will understand and know that for many years tuberculosis was treated with sunlight exposure here you can see in this first picture on the left in the uk there are young patients here that are outside getting sun exposure and they're here for orthopedic physical conditions we can see here in this nice hospital that they've actually purposefully built beds outside the hospital so patients could get sun exposure here's another photograph on the right-hand side where there's a area in the building specifically for people to come out and get sun exposure you know people were very observant 100 years ago they understood and they saw things that happened they may not have understood why they happened i think we're starting to understand that now but as i researched this more and more and i started to look to the literature i found some very interesting statements that i wanted to share with you these quotes were from a notable woman health reformer from the 1800s she wrote the feeble one should press out into the sunshine as earnestly and naturally as do the shaded plants and vines the pale and sickly grain blade that has struggled up out of the cold of early spring puts out the natural and healthy deep green after enjoying for a few days the health and life-giving rays of the sun go out into the light and warmth notice she says warmth here which is exactly what we're talking about in terms of infrared radiation go out into the light and warmth of the glorious sun you pale and sickly ones and share with its vegetation its life-giving health dealing power that was from the health reformer back in 1871 she also wrote interestingly because we talked about when it's daylight you need to go out into the sun well what do you do at night she writes make it a habit not to sit up after nine o'clock every light should be extinguished this turning night in today is a wretched health destroying habit you know i'm comparing what happened back then in the 1800s to what is happening now here's a near infrared photograph for instance of a summer day in a wheat field you can see that there is tremendous reflectance of near infrared as you can see by the white of the leaves and the wheat field and this is a little bit hyperbolic here but on the right hand side this is a near infrared photograph potentially of our home schools and offices why is that because the new bulbs that we put in our offices have no really to speak of any infrared light we have new types of glass called low e glass which are designed to block near infrared radiation from coming into the building because it's energy efficient our led bulbs are energy efficient and so we're not getting the same type of near infrared radiation that we were once getting before and as kyle mentioned at the top of this program we're spending 93 of our of our lives uh not outside but rather inside something if we look at this graph we can see here that back in the 1800s 50 of the time we spent outdoors we sat in front of camp fires which gives off of course infrared radiation and this was the amount of visible light that we were getting at the time and this is the amount of near infrared light it's estimated back by 1950 we had 100 incandescent light bulbs and we had plain glass windows and we spent about 25 instead of 50 of our time outdoors still much more near infrared than visible light by 1990 we had switched to 50 fluorescent bulbs and 50 incandescent we still had the plain glass windows but we only spent about 15 percent of the time outdoors so there was a reduction in both of those areas but today we are basically using bulbs that are only 100 in the visual spectrum there's no infrared radiation we're using leds oleds cfls we have this low e glass which is specifically designed to block infrared radiation and we're only spending as kyle mentioned at the beginning seven percent of the time outdoors and this is really specific to developed countries this is not seen in undeveloped countries they're still spending plenty of time outdoors we on the other hand are indoors here's a graph looking at led lights so led lights would be this red graph you can see here that once it hits near infrared there's literally no near infrared whatsoever coming from that bulb in the solar spectrum when you go outside you can see that a vast majority of the energy coming from the sun is in the near infrared spectrum you can't see it but it's there an incandescent light bulb here in blue you can see that there is a significant amount of near infrared radiation coming from a regular light bulb that we used to have in our homes 10 or 20 years ago so we can see that there is a shift in that direction let's talk a little bit more about low e glass so you can see here a regular glass here we're looking at the visible spectrum up here and we're looking at infrared here and specifically near infrared is in this red box so here regular glass plenty of near infrared that gets transmitted through here we have high solar grade low e a little bit less moderate solar grade low e glass a little bit less and then very low solar gain low e glass you can see almost no infrared radiation is allowed to pass through that glass how can you tell whether or not your glass is low e or not low e stand in front of it when the sun is coming through it if you feel warmth on the other side of that glass coming through it's probably a regular glass if you don't feel much warmth then it's blocking that beneficial i believe near infrared radiation so this is nighttime this is what nighttime used to be many years ago we used to gather around fires and we used to get this glow of a fire have you ever sat in front of a fire and felt that warmth maybe you went camping you probably found that it was pretty easy to sleep that night unless you're worried about bears attacking you in your tent but nevertheless the fire is low down it's reddish orange and it's got a low intensity to it compare that to now this is a visible picture of times square all sorts of lights bright lights high up and they're going throughout the entire night and that's really the difference between then and before let's talk really briefly about nature again in modern society so again we're looking at near infrared photons as soon as the sun starts to come up because near infrared can penetrate through that atmosphere it can go through a lot of things you're getting the benefit of near infrared both at the beginning of the day and also at the end of the day but because the sun has to be very high in the sky for ultraviolet to penetrate as you can see here most of that radiation is coming between the times of 10 am and 2 pm and so if you want to avoid ultraviolet light you can avoid those times but think about what happens naturally here at the beginning of the day you're getting melatonin your body is filling up with melatonin it's ready for the ultraviolet onslaught and then the ultraviolet onslaught hits at around 10 o'clock and then you get these free radicals that delay a little bit and then finally as that happens and it goes away then again you're getting that near infrared towards sunset to repair the damage that has already occurred so the three phases would be preparation for ultraviolet survival from ultraviolet and then finally repair from ultraviolet that's what happened when we spent time outside in terms of modern societies we're not getting any or very little near infrared radiation we're spending a lot of our time inside we're still getting those photons of light remember i showed you that graph that showed oxidative stress there was no wavelength that gave no problem there was always a little bit right most of it being in the ultraviolet area and then of course free radicals are happening as a result of those uv and hev photons or those high energy photons so this is not a good situation and it's not surprising that if we live in this type of a situation and then we get a straw that breaks the camel's back in the form of covet or sars kobe 2 that it can push us over the edge especially in a society where we have a lot of diabetes and obesity so kyle we've talked a lot about how humans interact with light we talked about sleep circadian rhythm and mood and now we've talked about the exciting aspects of near infrared radiation coming from the sun that can cause us to make melatonin in our mitochondria and protect us from a lot of these diseases that are associated with mitochondria okay dr schwald i have some rapid fire questions for you and the first is about light bulbs and you mentioned that the newer light bulbs led bulbs for example that many people including me have in my home and they're great for energy efficiency i don't know if we want to go back to the days of incandescent balls because they use so much more energy so are there any led bulbs that give off infrared light well actually kyle there are they are starting to produce led bulbs that can produce in the infrared spectrum unclear exactly how beneficial that's going to be but they are producing those and i'm sure further tests are going to be done on those do window screens or door screens block infrared light in other words can you open up a window and be close uh to the screen and absorb infrared light that way so the screens will reduce the intensity of the infrared radiation but um some of that infrared is going to come through all you have to do is sit there next to the door and if you're feeling that uh sun's uh the ray of sun coming through and it's warm you're probably getting enough but remember that you can also get infrared radiation not quite feel it as well so it depends on the type of screen as well there are some screens that are very thick and there's some screens that are very small so i think it's the answer is a qualified yes so speaking of light bulbs what temperature bulb do you recommend people have in their homes so the type of temperature that you need during the waking hours would be something more in the blue spectrum so you know four or five thousand k would be the type of bulb that we're talking about so full spectrum daylight whereas the areas of your home that you go to sleep in those are the types of lights in that area that you'd want to have a much warmer color so something like 2700k or 3000k and that's generally what we're talking about but again remember what we talked about is if you're getting ready to go to bed you should have those things on dimmers i think that's more important to dim those lights and if possible have the light coming from down below or on the wall low as opposed to overhead because of what we talked about with where those intrinsically photosensitive retinal ganglion cells are they're on the inferior portion of the retina therefore they're going to be sensitive to light coming from above so for the morning light viewing do i need to look directly at the sun or in the vicinity of the sun or can is it just enough to be outside um as long as the sun's out or as long as um you know i'm out during daylight hours even on a cloudy day so generally i wouldn't recommend looking directly at the sun like staring at the sun but but looking in the general direction of the sun i think is probably the most efficient way of getting the most amount of lux in the shortest amount of time i can think about you know a sunrise or a sunset there the light is not as intense and generally you can look in the general direction of the sun but for the most part looking in the general direction is better than looking directly at the sun you mentioned trying to get that morning outdoor light viewing as close to you know your wake-up time as possible what if someone is busy in the morning or they forget to go outside and go outside at 10 o'clock is it still beneficial is it is it less beneficial than if you did it right after waking up so from an infrared aspect it's plenty fine to get good sunshine exposure going outside at 10 or 11 o'clock in the morning you're getting good infrared uh light and exposure but from a circadian rhythm standpoint you're really the benefit of getting early light exposure in terms of anchoring your circadian rhythm and getting that in place the best benefit is going to be early in the morning as you go later and later the effect of that sun exposure is not going to be as much we briefly discussed this earlier but there's this optimal way that our circadian rhythm can be interacting with our environment and then there's reality some people need to work at night some people need to work on their screens late for various reasons um if people are going to be using screens after the sun has set besides a screen program that makes the light more red or using blue blockers are there any other strategies that one can use if they must interact with screens so the two pieces of advice that i would say at that point is in addition to what you've just said is number one try to make sure that it's lower in your visual field and we've talked about why that is but then secondly remember that the intensity of the light is what it is that's going to inhibit melatonin from being secreted and so intensity in terms of the equation for intensity is the inverse of the distance squared so what i mean by that is if you double the distance the intensity goes down four-fold if you triple the distance then the intensity goes down nine-fold so holding things further away from your face and holding it down low might improve the or diminish the effects of light on melatonin secretion so if i wake up in the middle of the night i need to check my phone for some reason i should probably hold that phone as far away from my eyes as possible dim the screen as much as possible and also hold it below the level of my eyes is that right yes and i find myself doing that more and more because just my vision um i'm a little bit more farsighted now and so i'm almost doing that as a as a reflex but that's exactly what i would recommend for people who can't go outside or they're working too much and they're not really able to go outside can they just take a melatonin supplement no so a melatonin supplement is only going to put melatonin into your bloodstream and that really only should be happening before you go to bed if you want melatonin where it needs to be which is in the mitochondria so that it's absorbing the oxidative stress you really need to go out into the sun or at least go outside so you can get the reflective near infrared spectrum there are other ways potentially of doing that with infrared saunas infrared lamps and there's a number of research articles that are coming out about the benefits of near-infrared saunas but again if we want to make this simple going outside is really going to help a lot of things and and sometimes the best way to get better is not just to take a pill or a supplement sometimes you actually just have to go outside and get nature's benefits i want to ask you about different latitudes so matching your circadian rhythm to what's going on in reality as you put it seems relatively doable if you live right on the equator or close to the equator where the average day length is pretty much the same but what about people living up in alaska or canada or extremely southern latitudes where as we know in the summer they're gonna have very long days maybe only a few hours of uh true darkness and the opposite in the winter basically dark most of the day of most of the 24 hours and just a few hours of light what should they do to you know anchor their circadian rhythm and have optimal health well they're going to have to change their environment around them when they're inside so the same technologies that have allowed human beings to live at those extreme latitudes uh in alaska and maybe way down there in in south america and maybe in the antarctic is the same technology that's gonna allow them to live well in those areas so um let's just take the the summer time if it's if it's bright very early in the morning make sure that you've got windows and uh and doors in your bedroom that are sealed off so you can control when the light comes in and when the light doesn't come in and then at night uh if if the the light again is coming in late in the evening and you want to go to bed you want to make sure that you've got your circadian rhythm make sure that you're able to block off that light and i would say the same thing as well in the wintertime so if the sun doesn't come up until very late that's going to be a problem so investing in a light box that will allow your circadian rhythm to be entrained and then uh obviously we have no problem with technology in terms of keeping the lights on in a house until a reasonable hour so we're going to have to use a little bit of technology because we're living in places that we're not normally used to living in dr schwell given all this great information that you've shared can you summarize it and also distill it down into some tips that we can implement right away so here are those three tips that we promised you number one get as much natural sunlight whether it's direct or indirect and it doesn't really matter in this case get as much as you can avoiding glass in between within reason and get it as soon as you wake up in the morning that's step number one tip number two exposure to low level red light fire or sunset at sunset time is advisable because you get that near infrared radiation and it kind of tells you when it is that you're shutting down in terms of your circadian rhythm that's number two number three is to avoid any type of light exposure after sunset especially blue light and we've talked about why that is and especially in the one to two hour time period before you go to bedtime we've already gone over why these are the case we've talked about the circadian rhythm we've talked about the mood aspect to light exposure and we've talked about the antioxidant effect of near infrared radiation and kyle i have to tell you that as a critical care specialist especially seeing that data in um in the netherlands and in england where over the previous seven day period of time that had changes in the metabolic activity of the body i have to wonder whether or not in covet 19 patients whether we should be advising that they go outside that they get into the sun or at least have indirect sun exposure and i'm looking at those photographs of those hospitals back a hundred years ago and wondering whether or not our coven 19 patients might benefit from some time in the sun as well well dr schwell thank you again for sharing your knowledge and answering questions and for those of you watching that have questions please leave those in the comment section below we love looking over those and hopefully we'll be able to address those in a future video and if you enjoyed learning from dr schwelt please visit us at our website medcram.com where you can see all of dr schweltz lectures over 60 different medical topics things like heart failure and diabetes and a lot of content on cova 19 and optimizing health and immunity and dr schwell anything else to add no i i hope that this was helpful and really i hope that everybody everybody that has access to youtube can see this video and understand the information because i think it's really important [Music] [Music] you

Channel: MedCram - Medical Lectures Explained CLEARLY

Views: 447,623

Keywords: melatonin, infrared, melatonin benefits, cortisol, visible light, infrared light benefits, what is melatonin, benefits of melatonin, melatonin health benefits, melatonin uses, melatonin for sleep, best source of melatonin, infrared light, light therapy, cortisol levels, electromagnetic spectrum, circadian rhythm, melatonin antioxidant, melatonin sleep, photobiomodulation, red light therapy, vitamin d, vitamin d covid, Sunlight: Optimize Health and Immunity

Id: 5YV_iKnzDRg

Length: 116min 10sec (6970 seconds)

Published: Fri Jan 21 2022