Fasting, Autophagy and Cell Repair - with Dr. Satchin Panda | The Proof EP 221

we all can relate that when we don't sleep well or when we eat at the wrong time then we can feel the consequences right away it's not a disease but it is a discomfort when it continues for many weeks or months then that can increase our risk for disease welcome to the proof podcast a space for science-based conversation exploring the health and longevity benefits that come with mastering nutrition physical exercise mindfulness recovery sleep and alignment facts nuance and trustworthy recommendations minus the hyperbole howdy friends great to be here with you i hope that you've been keeping well i'm your host simon hill i'm a qualified physiotherapist and nutritionist with an undergraduate science degree and a master's in the science of human nutrition in today's episode i sit down with professor sachin panda one of the world's leading experts interested in circadian rhythms to dive a little deeper into circadian biology and how we can use our understanding of body clocks to shift our health in a favorable direction if you're a regular listener you'll know that i recently had emily manoogian and courtney peterson on to discuss time-restricted eating a method of eating usually used to describe eating within an 8 to 12-hour eating window today's conversation with sachin builds on this with many important components of circadian biology re-emphasized and plenty of new questions explored i'm incredibly thankful to sachin for helping us continue to explore this topic of circadian biology and believe within this conversation there are several bits of information we can use to modify our lifestyles nurture our circadian rhythms and improve our health please enjoy this is me and sachin panda dr panda welcome to the show it's great to have you here happy to be here i've had a a couple of episodes on fasting now you and i were just speaking about those uh one with emily manoogian and and then a second one recently with emily and courtney peterson and since those episodes i've received many questions from the community about time restricted eating uh how fasting works and optimizing a fasting protocol that i'd like to to sort of throw around with you today to to sort of make sense of much of this conversation let's perhaps start with a refresher on what circadian rhythms are and and why they exist yeah so circadian rhythms uh daily timetable of when um nearly thousands thousands of genes in our genome on and off at different time of the day and the reason why they're there is for last 200 000 years we humans have been living on this planet with predictable changes in sunrise and sunset the availability of light the change in temperature and food [Music] so that's why we have been designed to adapt to that changing environment and when we dig deep what we find is circadian rhythms essentially optimize our physiology behavior and metabolism for every hour of this 24 hours day night cycle right so as we're going about our day these circadian rhythms are controlling our physiology metabolism can you give some examples what are some of the things that are kind of happening in our body at different time points and and how is that sort of uh helping us do what we need to do throughout the day yeah so for example if you were lucky enough to go to bed around 10 o'clock at night then after around seven to eight hours around say it uh you're supposed to wake up at six o'clock but your body your circadian clock actually prepares your body to wake up so your breathing becomes a little faster your heart begins to pump a little bit extra and then your sleep hormone melatonin begins to go down so that by the time you wake up you feel fully energetic and ready to roll just imagine when you set an alarm and try to wake up at four o'clock in the morning to catch a flight to do something um you actually wake up feeling groggy even if you tried to sleep little early because your clock did not allow you to prepare for the day so that's starting from the beginning from the day um beginning of the day and then after waking up within 45 minutes to an hour your stress on one cortisol begin to rise and reaches its peak and that means you are even more ready after waking up to do more physical activity and get ready for the day then your bowel movement is most likely in the morning because that's what your clock is uh instructing your gut to get rid of the toxins and then your insulin producing cells are actually primed so that you can eat your big breakfast and digest that food absorb that nutrient without raising your insulin a glucose level too high so these are just the examples even in the morning within within the past two hours you can see so many things happen and so when we're born are we kind of just born with these clocks a clock that affects say melatonin and cortisol a clock that's affecting bowel movements and and how to do sort of external things like cues like the the light that exposure that we're getting or the timing of our meals how do those affect those clocks and and potentially lead to sort of dysregulation yeah so we all are born with the same clock um around 24 hour switzerlands but then when babies are born the clock is not completely wired to the rest of the body and the reason is babies are also growing really fast so they need to eat in every three to four hours um to support their rapid growth so for the first six months to a year their physiology metabolism is not completely wired and this is a this is an example where you know if we have the same kind of um unwired cloth then half of us will be crying and half would be hungry now but slowly the clocks get synchronized and our brain clock gets more connected to the organ clocks and then we have much better rhythms in delhi physiology metabolism and behavior now the second question that you asked is how do light and food get into these rhythms as you as we all experience with the change in season when we go from summer to winter or winter to summer the day length changes and so that if we're in the wild we cannot just afford to wake up at six o'clock every day because sometimes in winter it may be too dark outside and in summer it may be too late in the morning so that's why our clocks wire to synchronize with the outside world are primarily through two different mechanisms one is through light so that as the day length changes the first ray of light in the bright light in the morning can reset our clock so that we are in sync with the day-night cycle um so for example in very northern latitude from day to day there can be differences of eight to ten minutes in sunrise time and that's why we are wired we have specialized cells in our retina called melanopsin cells the sense blue light and daylight or sunlight is a very rich source of blue light and that's how we adjust our clock to different seasons then the next thing is as our ancestors hunter-gatherers woke up when you are awake we want to go find food after a few hours of waking up so um the clocks in our body they also sense when the meal is coming because not only we have to anticipate when the sun rises and where to wake up if we know when the meal is likely to come then our digestive system also gets primed for that time so that's why when we eat also synchronizes our clock and essentially tells us this is the time when you should expect food so those are the two major mechanisms are there any other external cues that sort of have the potential to impact these circadian clocks other than light exposure and the time that we eat our food there are other mechanisms for examples on when we exercise can affect our clock [Music] but in face of light and food all these other cues are a little uh not that powerful but still we should keep those in mind so that we can use them when we cannot use light and food and so what's what's the problem uh sachin with circadian disruption so if these these clocks are a little bit out of whack why is that a problem from a physiological point of view and from a health point of view and and for a listener that's thinking um you know how would that kind of present how would that affect them in terms of how they feel or potentially their sort of long-term health yeah so just imagine if you're going to if you have an eight to five job and some days and if you are the boss and some days some of your employees they show up at uh 7 30 and then some days they can show up at 10 uh or they just randomly show up in the evening they may be working hard but then when it comes to promotion time you may not give them a rest because they're not sticking to time the reason is your office is also connected to the outside world through shipping receiving all the other stuff so similarly a body is wired programmed to do certain things at certain times and when we don't do when our behaviors are not in alignment with what our body is programmed to do um you may not feel means you may not see the consequences right away but over long term it essentially compromises our physiology we may not be able to digest our food properly or we may not be able to control our blood sugar properly so over days months or years that can slowly show up as for example diabetes obesity metabolic disease at the same time our clocks in our immune system also make sure that we mount very strong immune reaction when we are supposed to see pathogens which are mostly during daytime or in the evening and at other time the inflammation should subside should go down when we are resting so when our circadian rhythms are disrupted then our immune system doesn't see that um resting time or rejuvenation time so we stay with chronic inflammation and our risk for cancer and certain other diseases can go up similarly our circadian rhythm also has downtime for our brain to repair reset and rejuvenate and detoxify and if we don't sleep properly or if you don't sleep enough or if we have fragmented sleep then our brain cannot repair itself and then we can end up with effective disorder or depression anxiety panic attack etc all the way to even all gene risk how risk for alzheimer's disease or dementia can also go up okay so really does have the the capacity to affect many aspects of our health from the sounds of it do you have a sense as to how um important circadian biology is to our health sort of relative to some of the other big rocks that people talk about like the types of food that we eat or doing exercise or smoking or drinking alcohol you know how important is kind of nurturing these circadian rhythms in the big picture well it's really hard to say for example smoking and circadian rhythm health are difficult to compare so now if you think about circadian rhythms is actually an umbrella it's an integrating mechanism to integrate sleep physical activity um good nutrition all of them together for example if we don't sleep well then a brain doesn't work properly to decide what to eat or how much to eat so we end up eating energy dense diet or we end up overeating so when we think of managing our nutrition you may try to manage your nutrition but if you are not sleeping well or if you are staying awake late into the night then your brain may be confused it will actually make you that extra hungry to reach for that extra food so similarly when it comes to exercise if it's a very simple example if we haven't slept well and if we haven't eaten properly and if our digestive system hasn't digested our food properly it would be really hard to hit that treadmill and stay on that treadmill for 60 minutes or to go for a long run or to lift weight or whatever exercise you are doing so that's why the three foundations have held this sleep nutrition and physical activity um they're directly or directly controlled by the clock the clock tells us when to sleep and how much to sleep the clock also makes us to be hungry and to be less hungry at night it actually controls our appetite and satiety signal and it also um makes us uh it also primes our body to do better physical activity and gain best for our buck in terms of exercise if we exercise in the late afternoon so in that way this is this combines all these pillars of health that we know of so when we fix our circadian rhythm then everything else falls into its right place it becomes much easier to pay attention to nutrition activity and sleep very well said so all of these things are clearly very much linked and and sort of reliant on one another uh in some capacity i'm interested in the kind of origin story of your research so i want to talk about some of the early studies that that you did but what what was the kind of science that informed your hypotheses that led to your early research how long have have scientists been thinking about circadian biology and it's its relation to to human health yeah so the circadian rhythms um the point is we have been living with circadian rhythms for last 200 000 years ever since human uh started moving on this planet but only in the last 50 years we woke up to its importance because there is a lot of circadian rhythm destruction in our society and people knew about the bad effect or adverse effect of disrupting our circadian rhythm and sleep for very long time actually because at the beginning of industrial revolution for example in the uk women and children were not allowed to do shift work and one reason was they suspected that shift work might disrupt our bodies control mechanism and they may succumb to some disease and the 20th century this is again circadian rhythm is a field in biomedicine research which is not linked to any disease to begin with so for example cancer research started to cure cancer heart disease or cardiology started to treat heart disease but circadian rhythm actually started as a very basic curiosity about why a body keeps track of time and what became very clear was as people studied shift work or more and more who do night shift work day shift work and they have disrupted sleep they cannot eat or sleep at the right time it become very clear that the shift workers at a very high risk for many chronic disease starting from obesity diabetes to colon cancer to dementia but at the same time it was not clear whether the shift workers who work at night they also don't have access to healthy diet they may have other problems but i think the turning point was when the genomes were sequenced and we started studying how genes function and people started using modern tools it became very clear that almost our entire genome turns on and off at different time of the day night and second it also become clear that many genes that are known to cause disease they also have a circadian rhythm so that means uh the genes are primed to do certain things at a certain time and maybe when they're turning on and off at the wrong time as in case of circadian rhythm disruption among shift workers that can cause digits and people started studying this in in controlled condition in lavatory and they found that that hypothesis is right uh circadian disruption causes disease now you might ask what is cardiac rhythm disruption it is is it only for people who do night shift work so what is now clear is if we think of shift work as a form of circadian rhythm destruction then what is the definition of that disruption and it's now defined as staying awake for two to three hours between 10 pm and 5 am for 50 days in a year so that means at least once a week if someone is staying up late and working on something then that person is likely to be exposed to a lot of light at night that disrupts our shakirian rhythm and may have to wake up early in the morning to catch up with other societal commitments and why this two hours to three hours because when we stay awake for two to three hours one night extra then it takes us a body's clock needs two to three days to catch up to that lost time so as a result half of the week one may be working against the clock so now if we use that definition almost all high school students all college students many young adults almost every new mothers or anyone who is caring for someone else is going through circadian rhythm disruption and also we should not forget nearly one in five working adults in industrial countries also work in night shift evening shift or morning shift and they are also going through circadian disruption so that's why almost everybody goes through this kind of disruption and also we all can relate that when we don't sleep well or when we eat at the wrong time then we can feel the consequences right away it's not a disease but it is a discomfort when it continues for many weeks or months then that can increase our risk for disease i was going to ask you about that about whether it's been assessed how many people meet that criteria so i'm glad that you you touched on that so where are we going wrong then if if that many people are suffering from circadian disruption per that definition of um being awake for two to three hours overnight for 50 nights a year if i heard that correctly is it is it artificial light um is it the timing of our meals and how how has that kind of been established within the the field of science looking at this well i think this is where we have to look at the society and then why people do this one is at least 20 percent of people are card carrying shift workers so they they are the um you know doctors nurses healthcare workers drivers engineer airline pilots and they're essential workers we call them essential workers but they so we cannot live without them and as we're going more and more towards 24 hours on society then there is pressure on a lot of people to adopt that lifestyle and when we say someone is working as a shift worker there is also a lot of second one second hand shift work so for example someone's spouse may be staying awake late into the night to give company to somebody's dinner or breakfast or meal or staying awake to give company just to watch a late night movie uh similarly children when they are catching up with their and then some of it is institutionalized um so secondhand shift work may account for another 10 to 20 percent of the population and then when i say institutionalized uh for example during covered as we moved into digital learning one thing that happened was in many of the digital learning platform the deadline for submitting your homework became midnight because that's the end of the day in digital learning platforms so now if you look at in many us universities and high schools the deadline to submit your homework has become midnight instead of 5 p.m or 3 p.m that used to be so now kids are more likely to stay awake try to finish their homework try to finish so the end of that day has become midnight right then we get to ask another societal need a personal need one thing is the reason why we say in the evening we wind down because in the day time whatever we do that's for for our living some most of us actually don't like the work that we do so that's why we want to come home have a nice meal and then unwind so that means we want to feel free we want to be creative because the cradle of civilization actually started with fireside chat with that evening thought that's very free for being people who are creative and we want to do that we all want to do that we all want to check news we want to see the late night show so as our days become longer and we are spending more time for work we are also pushing um into our sleep we are spending more time uh entertaining ourselves relaxing so as a result only in the last maybe 30 to 40 years almost everybody is feeling this pressure too and it has almost become a norm to break your circadian rhythm and do more and at the same time we are also seeing that the fraction of people who are suffering from chronic disease is going up you might think that as we are becoming more modern we our food chain is more secure we have more safely produced food and we have a lot of medications vitamins supplements we may be healthier but we are not and i would say that that the circadian rhythm disrupts and may be something to blend and unfortunately the field is so new that there is not much epidemiological study carefully done to see whether that's true or how much is the contribution but this is where i put my money or say yes to this this accounts for a lot of increase and the risk factor for chronic disease your point about um doing work that we don't or we potentially don't love it or enjoy is a really interesting one and the sort of knock-on effect that that could have in terms of eating into our sleep um i guess it sort of stresses the importance there about trying to find some sort of occupational job that we do actually enjoy i understand that's not always possible but um it's a it's a kind of nice goal can we just take one step back you mentioned the early studies that confirmed and these were like the the sort of experiments that were conducted i believe most of this was animal research at that stage that confirmed that circadian disruption can negatively affect health at a sort of high level i know that you've conducted studies in that space what what are the sort of um most interesting findings that you've seen yeah so even in humans also there are some very interesting finding of course we cannot make people stay awake or reduce their sleep for months or years but what was really interesting to see was when healthy people who have normal blood glucose and not diabetic if we reduce their sleep by two to three hours in not we i mean in the community some other people who did these experiments then within within a week or two these healthy adults should develop telltale sign of pre-diabetes uh similarly circadian disruption by rapidly changing of simulating uh jet lag kind of experiments in animals without changing how much they eat or without changing the room temperature without changing any condition within the within the vibram or animal holding rooms people found that they became more and more susceptible to infectious disease so so the tiny bit of bacteria that usually the body could fight now the same amount of bacteria could prove lethal for many of the animals then the control studies also showed that when animals eat randomly throughout their night then experimental tumors grow much more rapidly than when the animals actually eat within a consistent time window every day and in many cases even feeding animals within a consistent time window shrunk the tumor so these are some of the very fascinating studies that connected circadian rhythm disruption are correcting circadian rhythm what are the kind of health impacts it can have i want to come to time restricted eating in this idea of sort of concentrating your calories within a a sort of more restricted number of hours over the day compared to the typical person and the potential benefits of that and some of the mechanisms that might be at play before we do that just to kind of close the loop while we're talking about just circadian disruption in general and the negative effects of not sleeping as as long as we should be what tips would you have for someone with regards to light exposure given that that's the other sort of main external cue we're talking about here what are some of the things that that you do at home perhaps sachin or you advice that you would give a friend if they asked you this question yes a light at night so there are two aspects to it when you talk about security under them it's always timing matters so so timing can make a good light junk uh this junk light could uh so in that sense we need bright light during daytime everybody needs that um and we should go out and get some daylight but as the evening rolls in um two to three hours before we go to bed a body actually prepares to go to sleep so even if we are not ready our body starts the preparation by secreting a little bit more melatonin and cooling us down and reducing our alertness so that we can fall into sleep but when we get exposed to bright light when i say bright light it's um 1000 locks of light of if you want to know what is that light like if you go to any grocery store these days now almost anywhere in the world grocery stores and drug stores are very bright these days so as you walk in within 15 to 20 minutes that amount of light can reduce your melatonin level and one thing is as we are remodeling our houses we are putting more and more bright led light and that's affecting our circadian rhythm so the rule of thumb is don't put anything more than 40 watts of light in your living room or in your bedroom bedroom can be even dim and when you are trying to change light switches even go for the dimming switch so that you can dim down your light so no bright light at least for two to three hours before your bedtime will help you not to go to sleep and also in our bedroom there are a lot of electronics that can emit light indicators so if you are sensitive to that then try to even have a eye mask or sleeping mask handy so if you cannot control light then at least get some darkness and then in the day time of course try to be outside for at least 30 minutes on the bright daylight you don't have to be under sunlight but even on a cloudy day being outside for 30 minutes it's pretty good to re-synchronize your circadian rhythm with the day night cycle right yeah i wonder if uh maybe grocery stores and pharmacies after a certain time like 6 30 7 p.m whether the the lights in those stores should potentially change should they be should they be a little dimmer later at night well so that's what i say that the the knowledge about light is actually used to keep the suppers awake and a lot so that they can spend more time buying stuff and also keep their employees away for that they're all right yeah you're not buying a lot of food if you're asleep um that's a little counterintuitive for their shareholders but um also that makes me think when we're thinking about pharmacies um sachin what about if i just decide to hack my way to sleep and and you mentioned melatonin there let's say i'm a university student i'm up all night lots of bright light but i buy a melatonin supplement can i just do that and is that a way of being able to stay awake for a long period of time and get the deep rest that i need yeah so that's a tricky question because you're trying to hack by popping a lot of melatonin when our body actually doesn't produce it for example during the daytime so there are actually conditions uh in which the body does that naturally where there is a genetic condition where these patients they produce a lot of melatonin during day time and less at night and as a result these kids they stay up all night feeling lonely and have some effective disorder and then during daytime they're also very sleepy and they're cranky the trouble with this approach is popping melatonin during day time is not going to reset your clock it's just trying to make you sleepy but at the same time a body's clock is telling our brain that it's not the time to sleep so one may not get that restorative sleep so for example it's very difficult to be in bed continuously for six to eight hours during the day and many of us who have tried it it's very difficult because you even if you have gone through an entire night of staying awake you may sleep for two to three hours and then you wake up and then it's hard to fall back sleep because the rest of the body is on that clock so it's not the best idea but once in a while if someone is trying then it may be okay i must also say that melatonin doesn't only make your brain to sleep it also has some effect on pancreas clog and our ability to maintain blood glucose level so during day time when we are supposed to eat having high level of melatonin is not good for glucose control in fact of blood glucose level may remain high as if we are pre-diabetic or diabetic so probably best for us to just sort of i guess uh stick to the the the night and day kind of um cycle that our ancestors would have had as best as possible and get out of the way a bit now and our body will take care of things like melatonin and cortisol probably much better than we would through supplementing let's let's slide over to to time restricted eating so i'm interested in where this kind of enters this conversation with regards to our circadian biology uh how what how many hours across the day does the average person right now say in america eat and how is this uh affecting circadian biology yeah so the concept of uh eating within a certain hour hours it relates to circadian biology in many different ways one is our digestive system is primed to digest so the overall idea is just like our brain can stay awake during day time solve complex math and then wants to sleep at night to repair reset and rejuvenate almost every organ in our body also has a peak time when it can perform much better and need some downtime to repair reset regions that's the overarching principle so now if we look at every single aspect of our digestive system you know um when we eat something it has to be digested in our stomach and there has to be a lot of acid secretion and then digestive juice all the enzymes have to be secreted so that the food get digested it takes almost five hours to digest a good size meal for example breakfast lunch or dinner so now let's start a math from the from the night time suppose say one eats around say eight o'clock at night although we finish eating at eight by eight eight fifteen a stomach continues to work for the next five hours to digest that food so that means around one o'clock or 1 30 in the morning that's when the stomach is finally getting some down time to go to go to repair reset and reach the length right and stomach lining needs to repair nearly seven to ten percent of the cells that line the stomach so that's a good amount of repair that happens and then um our lower lower intestine the food moves in our digestive system because of this peristaltic action because the uh the muscles contract and expand so that's how they move when the food moves but that action also slows down and also almost stops because the intestine needs to sleep so as a result the food actually doesn't move much um so some of you some of us who when we eat late at night next day we feel like the food is not digested and it's not just a feeling actually food doesn't get digested properly because the peristaltic movements stops so now uh if we think that your stomach just like a brain needs seven to eight hours of downtime to repair so that means if you eat at eight o'clock and if your stomach gets a break at one o'clock in the morning for the next seven to eight hours it needs that down time so that it can repair itself then one should not eat until at least nine o'clock in the morning next day so that's the simple math just for the just from the stomach point of view and there are many other uh there are many other aspects of our digestion nutrient assimilation that essentially tell us that we should be eating for no more than 12 hours in a day because we need that five hours of digestion after the last meal and then seven to eight hours of repair and rejuvenation to be ready for the next day and how how long is the average person currently eating over what's a typical eating window if you were just to go and grab the average american yeah so another point is we don't eat the same at the exact same time every day so for example i'll give you an example and you can actually give me the answer i'll give you some example and then ask you a question so for example suppose i eat today i eat my breakfast at six in the morning tomorrow it will be 6 15 day after tomorrow it's 5 45 another day maybe 8 o'clock or seven o'clock and um if somebody asks you his time on one does such a actually typically it's breakfast or when does his circadian system which is expects to eat food then the answer will be around six o'clock um because one day maybe i ate at 5 45 but usually around 6 o'clock 6 15 6 30. so now if we do the same math and then take two weeks of food data from somebody and then ask what is the probable time window in which this person is likely to eat 90 plus percent of its meal then the number that we get is 14 hours 45 minutes so nearly half of the adults in the u.s who are not doing shift work because for shift workers it's even worse um nearly 50 of adults eat for 14 hours 45 minutes or longer less than 10 percent of people actually eat consistently within 12 hours or less so that means there is room for improvement for almost all of us to improve our health just by paying attention to when we eat or when we property right and you you said it takes about five hours to sort of digest the last meal that you have at the end of the day and then after that you need about seven to eight hours to to kind of get that repair process happening um can you just define a little bit deeper what what repair means is this where things like autophagy i often see sort of brought into this conversation um is this where processes like that sort of come in yeah so there are many types of repair um so let's start with the gut because during during the day we eat lot of different stuff and then there is also enzymes and acids that are secreted and we damage nearly eight to ten percent per stomach lining and you can think of this as the your highway or the road or you can think of the cobblestone road where you take out eight to ten percent of the stones every day and they have to repair they have to be physically replaced and the way that happens is growth hormone from a pineal gland is secreted and actually the secretion goes up with two signals one is fasting and second is our deep sleep so if we haven't eaten for several hours and if we're in our deep sleep then the growth hormone is secreted that gives a signal to the stomach lining to divide and replace these damaged cells or dead cells and this is a very relatable repair process that we can think of and similarly in the brain when we sleep then many of our toxins brain toxins that do get secreted into the outside of the cell it's almost like taking the trash can out and leaving it outside for the for the uh for the truck to come and pick it up so that also happens so that's like taking the toxin real literally out of the body and you also mentioned autophagy and autophagy also occurs after several hours of fasting so that's internal almost like recycling process within the cell so all three types of repair where you are recycling within the cell taking the truss out outside the cell and even replacing the entire cell when it is damaged all these three types of repairs happen uh during our fasting plus sleeping and so you said we we should aim for at least 12 hours of period without food right yeah um so what would you if we were to kind of just at this point before we keep going if we were to kind of define what you think is the optimal eating window and and sort of translate that into what that looks like in in the standard person's daily life so not a shift worker just a standard person what would that look like in terms of the time that someone say wakes up their breakfast lunch dinner and bedtime yeah so let's start with the bedtime because your next day actually begins with when you go to bed so try to be consistent in going to bed and then try to be in bed for eight hours so that you can get seven hours of sleep and then after waking up one should wait for at least an hour or two before eating anything with calories because that's the time when our sleep hormone melatonin goes down cortisol rapidly rises and reaches its peak and then slowly adjusts itself and our insulin function our insulin secretion is adversely affected by both process insulin sorry by melatonin as well as high level of cortisol so that's why one should avoid food for one to two hours in the morning and then have your breakfast at a consistent time because since our clocks get synchronized with each other and with the outside world by two signals light and food and actually over the last five to ten years what we are seeing is food is a much more stronger signal for all our peripheral organs than light light is a very good signal from for brain but food is very strong for the rest of our body so so eat your breakfast the first meal that has calories at a consistent time and then try to eat all your meals in the next 8 10 or maximum 12 hours and in most of our clinical studies we target 10 hours because eight hours is a little bit difficult for long-term compliance if somebody can do eight hours for a month two or three that's fine but many of us cannot do it for uh for our rest of our life so it's a good goal to have 10 hours so that once in a while you can eat within eight hours and once in a while if you if you cannot and go towards 11 or 12 you're not actually breaking not doing too much damage so that's why 10 hours is an ideal target so an example of that could be 9 a.m to 7 p.m um okay i've got a couple questions on a few things there so one that comes up and a lot of people sent me this section was okay within that fasting period in the morning before you have that first meal would things like supplements or medications or tea coffee let's say black coffee would they be permitted within that i mean no one's no one's watching but i'm thinking from a biological point of view um yeah are they are they going to interrupt these biological repair mechanisms that you mentioned or would they be okay to have in that fasting period so again this is a question that we cannot do any clinical trial or systematic study even in animals we cannot shed animal coffee every day before we get the meal but this is where we got to use some common sense and arrival so there are many medications that need to be taken with empty stomachs so so people should continue to take downs in empty stomach best example is thyroid medication uh people who are taking levothyroxine that should be taken empty stomach in morning so that's fine sure where it kind of becomes gray john is coffee coffee with little bit of people will say i just put half a teaspoon of sugar a little bit of cream just to make it palatable and um one thing is it it relates to what is your goal if your goal is to lose weight or maintain your blood glucose level then maybe a mild coffee or tea is is okay so that's why we said there are three exceptions to the rule one is if your job depends on it for example there are a lot of shift workers they have to wake up early in the morning they have the morning shift they have to be fully lot and for them tea or coffee is kind of having a job on her job for example if you're a tv presenter you have to be awake second is for public safety you should not be driving on the road sleepy it's better to be a little bit caffeinated and then the third one is if you really cannot function without coffee that's the only love in your life then you can have it but here is the thing how it affects so there are a lot of people who cannot drink strong coffee or tea for long term in empty stomach because that can lead to acid reflux or even panic or anxiety attack because they just the body cannot tolerate this strong coffee so if you're one of them then try to see whether you can reduce your coffin dose or if you can delay that for an hour or two and have it after breakfast in fact in many in turkey the literal meaning of breakfast means the meal of the meal before coffee because a lot of people can have acid drip flocks in empty stomach now let's come back to the physiology and see what is breaking a fast or what affects your body so that your insulin production and everything else begins to start so if you take me and drain all of my blood and figure out how much blood sugar i have then the official blood sugar level for somebody healthy is it should be less than 100 milligram per 100 milliliter so that means if you find five liters of blood that is the average blood that you will find from a person like me then i have five grams of sugar in my blood and if it goes to six grams then it will be 120 milligram for 100 ml and you diagnose me as pre-diabetic and if i have 7 grams then i am diabetic because my plastic blood glucose will be 140 so that means if you add just two grams of sugar half a teaspoon of sugar to your coffee or tea that can raise your blood sugar to 140 milligram for 100 ml that means at that time your pancreas will begin to kick in and produce that insulin to take care of your blood sugar so you are essentially waking up your stomach your liver your panthers and whole body so that's why if you do the math and then think of what actually happens then it makes sense to understand that even that tea or coffee with half a teaspoon of sugar or a little bit of cream is breaking your past what about if it's just a black coffee sachet i just want to dig a little deeper here let's say i let's just say i love i to be honest my morning coffee um i don't always have a double espresso sometimes i have a macchiato there's a little bit of oat milk or something in there so i understand that's probably going to throw you out of a fast but let's just say it's a double espresso um what do you think about that are we including that or are we taking that out yeah i mean i'd say the thing is you know you are a very healthy fit person and a lot of us who are thinking about this black coffee thing we are really healthy and fit i'm talking about people who really need the fasting and they just cannot live they think there are a lot of people who think that hey having tea with it if you're in the uk or in india and in many parts of the country the world they will think that having a cup of tea with with a biscuit is not breaking my fast in fact when we interview people one is your breakfast time people will say ah eat at nine o'clock or ten o'clock in the morning and then if we ask well after you wake up what do you eat or drink then they'll say that i have a cup of tea with milk and with a biscuit or something so we're talking about those people and they have to end up understand what is breaking the breaking the fast and for a lot of us having it having a double espresso is actually not kicking our pancreas to high gear to produce insulin and that as i said it may not break out fast we may continue our lives i want to come to um blood glucose and and how time restricted eating can be affecting various aspects of our health particularly if we have sort of metabolic dysfunction or poor metabolic health but while while we're talking about healthy folks here if someone is let's say lean from a physiological point of view all of their kind of biomarkers or risk factors are under control is there a benefit from eating within a shortened window um would they be getting any benefit from time restricted eating at all yeah so there are a lot of people who complain about their sleep so what we have what you are seeing is both in animal studies and human studies the people who do eight to ten hours time restricted eating the first thing they mention is they sleep much better and we don't understand the mechanism but we are seeing that the sleep improves another thing that we also see is a lot of people who believe they're healthy they don't have any metabolic syndrome they don't have any metabolic disease they might have acid reflux they might might have bloating they have might have indigestion once in a while and that reduces their productivity and what we are also seeing is all of these digestive issues become much better so for example personally i used to have acid reflux and you know many acid reflux medications should be by my bedside and i would lose sleep sometimes and after i started time restricting 10-12 years ago i haven't gone to i haven't bought any new acetyl plasmatic meds i haven't used that so this is one example where people actually will benefit and second and another thing is [Music] you know in long term we all are healthy we may be all healthy now but if you think of what is what is your health goal i used to say that if you can be healthy and without medication till your kids go to college or until you hit 50. that's actually a lofty goal and you cannot do that unless you start planning very early so time rested eating is almost like preparing for your retirement savings it starts the day you start working from that day you start saving similarly to add those extra decade or decades of healthy life people who are healthy they should actually start doing this yeah when when you break it down that way it makes my question look a little silly because it would be like saying should we eat a healthy diet today if we're otherwise healthy or should we just wait until we have have disease and then think about it um so i think you answered that well thank you um let's let's talk a little bit more about blood glucose because you've mentioned that a few times and you know a staggeringly high number of people have type 2 diabetes there are many people with pre-diabetes i'm interested in how time-restricted eating can be utilized as a tool to help better blood glucose control so what's the kind of relationship between the time of the day our meal and blood glucose control and as an extension of that perhaps you could speak to something that emily and courtney also spoke to which is this idea of early time restricted eating versus late time restricted eating when it comes to to blood glucose control and if someone has pre-diabetes or type 2 diabetes what are some of the things that they should be thinking about here yeah so that's a very loaded question so i will i'll break it down so um you know when we think of circadian rhythm we always think of connecting it to sleep but actually circadian rhythms are much more intimately related to blood glucose the regulation of blood glucose cholesterol and fat and let's begin with what happens how all of these are connected and this is very important because as you mentioned nearly half of the adults in western countries particularly in the us uk australia are either pre-diabetic or diabetic type 2 diabetic and this trend is also going up so that means what we are doing as a as a society is something is very fundamentally wrong and that may be this uh eating randomly over a long period of time um so they said in the morning for example when as soon as we wake up if we eat then at that time our pancreas is not ready to assimilate food in a way that our blood glucose remains healthy one thing we have to keep in mind that we always say some diet is rich in protein diet is rich in fat but the bottom line is almost all food that we eat has some carbohydrate uh unless you are just eating pure oil or pure meat but for most of us it contains some carbohydrates so that's why avoiding meal for at least an hour or two in the morning will help in preparing our body particularly our pancreas to respond to that carbohydrate in a healthy way in the morning and the second is circadian rhythm research is also showing that the pancreas is much better in responding to food and secreting good amount of insulin to control our blood glucose uh say two hours after waking up to for the next six to seven hours or eight hours so that means eating a good big meal in the first half of the day is much better in controlling blood glucose because our digestive system and ins and pancreas are better in handling big meal i think that's a a really important point sorry such and just to reiterate something there um given the number of people with poor blood glucose control that could benefit from this as a tool i think this is worth kind of double clicking on because if you think about say intermittent fasting or the standard sort of eight-hour protocol that became very popular i know in speaking to a lot of people that that many people did a sort of mid-day to 8 pm style eating window but from what you're saying um if you're wanting to get improvements in blood glucose control and if that's something that you're struggling with it might be more beneficial to kick-start that eating window slightly earlier than that yeah but not too early that right after you wake up you should start eating so i have like two hours uh wait time after waking up and then try to eat around 9 or ten in the morning if you can or if you're waking up too early maybe even eight o'clock is okay um then there's another aspect that we often forget is okay so let's work on the end of the day so what happens is for most of us our body begins to prepare for sleep by producing melatonin two to three hours before our bedtime so that means if i'm going to bed around say habitually around 8 10 o'clock at night then my body starts making melatonin at eight in the evening so melatonin uh for some for nearly half of half of the population melatonin actually inhibits insulin release from pancreas so that means if someone if i have my dinner at seven o'clock and my blood glucose is still high my pancreas is kicking to produce enough insulin to bring that blood glucose low then insulin sorry melatonin comes in and inhibits that process so that my blood glucose can stay high for several minutes or even an hour or two longer so that's why having your last meal three hours before at least three hours before bedtime is a pretty good idea so that you your body can kind of use that glucose without raising glucose blood glucose too high would that mean sachin um sort of continuing that train of thought there um would would that therefore mean if you're a shift worker and you are eating overnight that it would be better through that shift to be around bright light so that you don't get that increase in in melatonin as you're then eating those meals yeah so if you're a shift worker and you want to and your shift is ending say seven or eight in the morning and you're coming back home at nine so then um your again your last meal should be around four to six o'clock in the morning so that you give yourself three to four hours come back and have a nice dark room where you can sleep and as you said enough light so that melatonin remains slow okay and when we're thinking about um the these sort of benefits with regards to blood glucose control or just big picture here i think this idea of um meal timing versus calorie restriction inevitably it comes up a lot and i'm sure this is a conversation you've had many many many times and i know that courtney peterson's work and she explained on our episode showed improvements in blood glucose control that were independent of um of weight loss which was really interesting yeah which which sort of suggests that um at least in that study those subjects had improvements in blood glucose control independent of actually losing weight so it's kind of i want to zoom in here a little bit on time restricted eating versus calorie restriction and i think the the first question that i'd like to to kind of throw at you which is often overlooked is um as i understand it time-restricted eating naturally leads to calorie restriction and and if i'm right there i'm wondering so in your studies when you or or in your colleague studies when you get humans to eat within a 10-hour eating window what happens to calorie intake how much if at all does it kind of fall by on average yes there are two parts one is in the laboratory condition when we do all the animal studies we keep the calories constant so the animals eat the same number of calories whether they're eating randomly at random time or within time restoration so that's why the term time restricted eating was coined because the calorie was not restricted time was restricted right when it comes to humans um since we all over it we are eating more calories than we need and mostly we eat more calories that we need by eating over a long period of time it's not that we are squeezing all that calories into six hours and eating a 3000 k meal we actually eat extra because we eat late into the night or we eat too early in the morning or both so as a result when we reduce our eating window then there are few things happen one is people report that particularly when you eat within eight to ten hours people actually feel less hungry so they are not craving for that food so as a result they eat less and they can reduce their caloric intake and most many studies where this timeless reading is being tested in those studies people are overweight or obese so that means for life long they were eating more than what their body needs and when you reduce that time window then inadvertently they reduce that caloric intake by 10 to 20 percent in some studies 10 percent in some studies 20 percent and on an average this is the group average 10 to 20 reduction and then at the same time you see all these improvement in glucose blood pressure and everything else so people always assume that the the effect of time restriction is mostly through caloric restriction but as courtney pointed out and in many studies if we look at individuals then we do see individuals who are not reducing their calories but they still see benefits then there is another aspect of this that is not all diabetics are overweight obese um nearly one-third of pre-diabetic and type 2 diabetics are actually within healthy weight traits and they're still they cannot control their blood glucose level and for them the advice is not to reduce calories because they already have normal weight and if they reduce too much then they may become dangerously underweight so then the question is for normal weight people with pre-diabetes or diabetes is intentional cataract restriction or time restriction which one is going to work and no one has done that study so that would be an important study to do to see whether these effects are there one thing that we are also forgetting that you know diabetes doesn't come alone it has its sinister friends and kind of in the last book and circadian diabetes score i describe that many diabetic patients patients with diabetes also have hypertension or high blood pressure many of them also have high cholesterol they may be taking statins to control their cholesterol and we know that nearly a good proportion of people who take starting they cannot tolerate it because they have muscle pain and then the question is can time restriction help to help for these people who are already having telltale sign of pre-diabetes or type 2 diabetes have hypertension are have high cholesterol and they're on what we call polypharmacy they're already taking more than two two or more medications and can time restoration help because these guys have already gone through trying to do caloric restriction because the first line of lifestyle intervention any physician will say is eat less and move more and they failed that and in our study what we're finding is yes these people a lot of them can actually adopt time restriction and when they do that then the blood pressure regulation is much better they can whether they are on medication or not on medication they always see improvement in both systolic blood pressure and diastolic blood pressure and then uh yeah but what you just said is really really important and worth emphasizing that for some people counting calories hasn't worked and it's actually i see it as uh a a nice um we're in a nice position to have multiple tools here and i think i've heard you say before that um people often have great difficulty counting calories but counting time is much easier if i recall correctly i think that's a quote i heard from you yeah so for example between you and i i cannot i cannot count and tell you how many calories i have eaten today but i can tell you exactly when i had my breakfast and even my lunch and snacks so we are much better because we are designed to count time so we can count it um yeah so so these are some of the examples where it's not only controlling blood glucose but with blood glucose misregulation there are many other diseases that come with it and time restriction can help manage those um those conditions and also um i must say that counting calories is important particularly when you know someone is eating say 4 000 kcal and [Music] there are a good chunk of population who actually overeat they eat more than 2500 kilocal more than 25-30 percent of what they need and sometimes those extra calories are actually consumed late into the night or at random times so time restriction actually can be a way to manage or to improve caloric restriction right so that's a new approach that even the even card carrying researchers who do calorie restriction studies they are coming to this understanding of coming to accept that time restriction can be in that toolbox to help people reduce calories so tell me with regards to kind of looking forward future research i think it's you know you've made it clear here that time restricted eating can certainly help someone reduce calories and there will be some benefit through that absolutely and that that can be a great thing for someone who's struggled counting calories i don't think anyone's debating that you're also saying that your position is that there's some independent effects of restricting your eating window independent of weight loss and my question that i kind of would throw to you here is given that there is debate out there that i'm sure you're aware of what kind of study would it take or is there a study that you're excited by that would would see time restricted eating potentially end up let's say in in dietary or in lifestyle guidelines i think it's already in lifestyle guideline and the american heart association put a position statement several years ago uh saying periodic fasting overnight fasting is good and um even the caloric restriction researchers would accept the idea that one should not wake up in the middle of the night to eat a small amount of calories [Music] so that means that everybody accepts the fact that yes we should not eat for at least seven to eight hours when we're in bed and nutrition scientists and gastroenterologists will also say that one should not eat one to two hours before going to bed because your core body temperature is high you cannot sleep well you cannot digest well food so the bottom line is people accept the fact that one should fast or one should not eat for at least 10 to 12 hours a day then the other question is okay so um is it should people eat within 10 hours or should people just eat within that 12 to 13 hours and reduce calorie and i think this is where um [Music] the benefit is so little or the difference will be so little that you need to have a very large cohort clinical trial and also pick the right type of target population who can do this the question is is that worth it or should we do it in animal studies because in animals we can control many of these and in fact one of the best animal studies addressing this was just published few weeks ago and i wrote a editorial in science sorry preview in science about it and the experiment is very simple people know for almost now 90 years that rodents whether it's rats or mice if you reduce that caloric intake by 10 to 20 percent then my sleep longer or add sleep longer and that's the foundation for proposing caloric restriction to increase lifespan so now few years ago almost um six seven years ago scientists also figured out that the way the animal experiments are done [Music] the characteristics and studies are done they were inadvertently doing time restriction because the control mice would be given say 10 grams of food or x number of food amount of food and that's they consume throughout day and night because food is in the food hopper they have access to food all the time and then the researchers should come back and calculate how much food the mouse ate and they would put 70 or 80 percent of that diet in one meal at one time in the late afternoon or evening and then mice would eat that within two to four hours and then for the rest 20 hours they were fasting so practically they were doing both caloric restriction and time restriction at the same time so then the question was whether how much of that lifespan expect extension was due to calorie restriction and how much was due to time restriction so that became very clear that this is an important question to ask so the experiment was not very easy to do because we have to design a lot of engineering tools to feed mice tiny amount of food throughout day and night so these researchers they brought mice and then divided them to many different groups one group got to eat whenever they wanted and they figured out how much they lived they reduced the calories and then fed them [Music] in i think nine or ten equal meals throughout 24 hours so they didn't have any time restriction but they have caloric restriction and by doing this they found that this might sleep 10 percent longer so that's very clear that by caloric restriction you can make mice live 10 longer and there is no time restriction because in every three hours these mice were eating something now they said okay so instead of feeding them in every three hours if we feed them in every 80 minutes or 90 minutes and give them the same amount of food either during the day 12 hours or the night 12 hours then what happens or if we do them if we feed them in day two hours a night two hours then what happens what they found was when the mice ate within 12 hours during the day when they even not supposed to eat then they lived 20 longer so that means time restriction alone without aligning to the right time even extended their lifespan another ten percent so now this as okay so what happens if the mice are given the same amount of food but in night time because mice are nocturnal theirs their circadian rhythm is designed so that they have to eat at night and when they create them at night time they found that the mice lived 35 percent longer so now imagine caloric restriction alone extends lifespan by 10 any kind of time restriction day or night can extend lifespan another 10 and if you align the time restriction to the right time of the circadian cycle then you can get another 15 benefit right that experiment i think nicely answered this question that in animals at least this kind of likes an extension happens now if you circle back and ask what happens in human experiment and what did they find in mice one interesting thing was they found all these mice that had caloric restriction whether a daytime nighttime or throughout 24 hours they had the same exact body weight they all lost weight that the same exact muscle mass the same exact fat mass and this similar very similar level of insulin so that means your weight loss your muscle mass your fat loss all of this that result from time restriction or caloric restriction is not going to predict what is going to happen to lifespan what is going to protect you from disease so that remained unanswered so the question the answer is yes we cannot just look at weight loss as an outcome in human studies in caloric restriction or time restriction and say hey there is no contribution of time restriction right or so so fortunately the experiment is bigger than animals we don't know what to measure in human to compare the benefit of time restriction plus calorie restriction versus calorie restriction alone that was my question so short of kind of running a trial for for many many decades um what would be a biomarker or something that you could measure to say hey look tre is affecting this marker which we know is it is predictive of longevity but calorie restriction is not um and it gets me thinking if we circle back there was a word that we we spoke about before autophagy and that often comes up in this conversation and one of the questions that i was sent from people in the community was you know autophagy seems a little bit abstract is it actually something that you can if you look take a peek under the hood can you objectively measure it yeah it's really hard to say and also we should not think that autophagy is always good because in fact in cancer we have to stop autophagy we have to reduce autophagy because cancer cells do excessive autophagy to recycle and grow so i think the point is we can just use common sense if we take you know our body essentially is a function of 10 or 12 critical organs that function um if we measure all these functions bone mineral density for example for bones muscle mass muscle strength then long function liver function adrenal function reproductive function all of this and then come up with a massive questionnaire and measurement tools then we can ask okay those are the health outcomes then the participant bottle whatever you do at the end of the day if the participant has to work a lot to figure out what he or she has to do then that particular lifestyle is not going to be scalable at the population health level so that's the second aspect and then the third aspect is the economy of scale how much time and how much energy how much resources are to be spent to make one person stick to that lifestyle we know that for example diabetes prevention program which emphasizes on reducing calories eating better food and doing more exercise that has a price tag and you know depending on the technology it has gone from four thousand dollars a year to fourteen hundred dollars a year so similarly we have to come up with a price tag how much it takes to educate an average joe what is time restoration and what is sensibly this person can do so if you take health biomarkers or outcomes then participant burden and the and then the financial cost to the society or to the person then we ask okay so what can we do to improve health whether caloric restriction alone time restriction alone or a combination of even three time restriction caloric restriction with better diet and i think that would be the answer optimum diet just enough calories within an optimum time window but i guess what will happen is some people can adopt one two or three and the the responsibility of scientists and clinicians is to give these options and make sure that these options each individual or the combination of two or three uh can benefit the person yeah i think that's a really um interesting way of looking at this because it often feels like one threatens the other with regards to researchers working on different areas or just people in the public that are sort of passionate about one of these and i get it you know there someone has a personal anecdote let's say for example they did a a shortened window and they lost 50 pounds and then the next person counted their calories and lost 50 pounds and they're both equally as passionate about those being the kind of best tools um but i think it's a really interesting proposition to think about i would hypothesize that if you could improve diet quality and get people eating over less hours that calories would be significantly um lower per day on average um i want to come back to the protocol a little bit more because we spoke about that 10 hour window sort of 9 a.m to 7 p.m being something that that might be achievable for many people um recently i heard a colleague of yours i think you've published a few papers with him dr voltalongo uh expressed his kind of thoughts about fasting for more than 12 hours and he didn't seem to be a big fan of that and a 10-hour reading window i guess is a 14 hour fast and there are probably people listening here that have that have heard um dr longo sort of express his opinion on that and and i wondered sort of where you land there what is the what did he say well i think he said that he he he doesn't think for longevity it's optimal to be fasting for more than 12 hours a day is there any data not the question yeah well that wasn't that wasn't shared so i think that's a great question but one has to be objective you know a lot of people have their opinion and i cannot answer i cannot address just somebody's opinion um because if there is scientific fact then i can go back and see whether the point is almost every animal studies that did caloric restriction even his own early carotid restriction studies they actually fed the animals for less than six hours and all of them lived longer than mice that eat healthy diet for longer than 12 hours okay so if if this thousands of caloric restriction studies it's not one or two it's literally thousands because this has been going on for 90 years if they have shown again and again and again that feeding mice for less than 12 hours in multiple labs in male and female in multiple strands in mice in fly in in rats and even in monkeys if they're not adversely affecting health then there is no point to discuss this uh based on one opinion okay yeah so so i guess i could rephrase that you're in and and you've i mean you've already made it clear but what you're saying is you think a 10 hour there's no reason to think a 10 hour eating window is not safe would be a better way for me to kind of position that um and also another thing is we actually there was a study done then there was a study done in europe where they tried 12 hours time yesterday eating and did not improve any health indices for people who were unhealthy so the experiment has already been done it doesn't improve health one question that comes up here a little bit is how much of this research has been done uh on females and different different ages different life stages i know there's a again this is an opinion that i've seen out there and has been shared with me by a lot of people so i'm not getting you to comment on um the opinion so much but more um your sort of feel for the evidence that that exists out there and where you land but there is a doctor that has been sharing information online stating that their the the tre studies haven't really included many women sort of aged 40 and over i believe and that she doesn't believe that time restricted eating is kind of healthy for um women of that age how do you how do you sort of feel about that again that's an opinion and you know it's good that we have to include more women in studies and we've got to see whether they will benefit or not but the animal studies have again shown that both young middle east and also a little bit older female animals still benefit from time restricted eating in fact for in animals time ratio eating extended their reproductive lifespan so that means these animals were still ovulating at the older age when the lip fed mice have stopped ovulating and then in our studies what we have found is female mice who were eating within nine hours they were completely protected from endotoxin shocks um which is similar to bacterial infection so in our study what we found is male mice that were at least unfair nearly half of them more than half of them died when they are challenged with endotoxin shock and nearly one-third died when they did time ratio eating the female mice on the other hand all hundred percent of them were completely protected none of them died if they had done eating so that's again another example means people always you know people are stuck with this idea that personal opinion and that conviction and they think that okay women cannot lose weight older women and it will not help the thing is people have to be a little bit open-minded and then that means it's a good question to us that yes there should be more women in clinical trials and in fact there are many in many of our studies also we have included women but the i must say that the number is not large enough to do statistical analysis on individual gender and then figure out whether it is what we have seen is many women they want to try all at the same time and they also want to get most out of it so then what they end up doing they will try to do four to six hours of time restricted eating so they are fasting for 20 to 18 hours they want to reduce calories significantly so the only thing they eat is salad and few other nuts or something at the same time they want to run a marathon and then what ends up happening is they are more likely to become a menoric and more likely to have low bone mineral density and brittle bones and that's what happens and it's actually there is a syndrome called relative energy deficit in sports and rats is more prevalent among women but also there are many men who succumb to rats so we have to keep that in mind that maybe some people took it to too extreme and they are the ones who might have suffered and it's always those few other data that complicate the field you mentioned there uh the they kind of uh my studies that have that have had uh male and females and and i think some people might be thinking about the kind of uh reliability of translating findings in that research to human research um and i know that you're a big proponent of of multiple lines of evidence but just with regards to circadian biology and thinking about hours um is the circadian clock in a in a in a mouse because i think we kind of glossed over this but is it similar is it a 24-hour clock and and thus those eating windows in those experiments are quite easy to kind of translate to to human eating windows as well yeah the clocks are very similar and in fact most of the clock genes and the mechanisms are identical or well conserved between mouse and humans metabolism we all know that there is some differences so for example uh 14 hours fasting and mice maybe a little bit this will be equivalent to more longer fasting if we just think about the if you're thinking only about glycogen depletion or fat oxidation but many circadian best parameters so for example when i say gut repair or there is a time window in which within which the gut has to repair or there's a time window in which the insulin producing cells are more active all of those mechanisms are very similar between human and mass so that's why we have to keep that in mind that well there are some aspects of metabolism those are different but when it comes to repair rejuvenation reset is a very similar i'll give you an example how much do you think a mouse little mouse that is 30 grams that weighs 30 grams runs every night how many meters or kilometers you would think oh gosh a little mouse uh i'm gonna say i'm gonna i'm gonna i'm gonna guess 1.5 kilometers a month can run somewhere between seven to 12 kilometers every night gosh so that means i should run between here and san francisco every night if i extrapolate that but you know that doesn't extrapolate that way linearly many things don't extrapolate so in that sense yes as the animals are smaller and smaller they actually have a different metabolism just think of the hummingbird how much it has to fly to get tiny nectar so in that way there are differences um but when it comes to circadian rhythm or circadian related stuff then there are similarities in fact a few years ago we did a very simple experiment we asked does the benefit of time distributing depend on circadian clock which is a very you know counter-intuitive experiment to do from my lab because we always think of circadian rhythm but what we found is yes it does actually benefit even mice that don't have circadian clock because of genetic defect and the reason is this why we did this experiment there are many genetic models of mice and laboratory animals that also succumb to similar metabolic disease as humans do and as genetic testing is becoming more and more widespread we always we often blame it on our gene we say hey i'm diabetic because it runs in my family i cannot help it but actually the point is if you have a faulty gene then you can adopt good lifestyle to reduce the adverse effect of that fault dj and this is very important when it comes to a healthy lifestyle the healthy lifestyles are actually something that we can do to address our faulty gene because we cannot change our genes but we can change our lifestyle and when we change our lifestyle we can significantly reduce the risk from many diseases so that's why we did the experiment but the bottom line is yes even time restricted eating can override faulty genes that make mice obese diabetic or even have cardiovascular disease repair rejuvenate reset has come up a few times here and something that i think people might be thinking about is the longer that i'm fasting do i get more compounding benefits with regards to repair rejuvenate rejuvenation and resetting this the system so to speak and you know online you'll you'll you'll see people um posting about doing 24-hour water fasts you'll see people talking about three day water fasts i'm interested in sort of hearing from you is is the longer the better or is there a kind of sweet spot where you kind of maximize benefits and beyond that it could even be deleterious i think i this is where i want to bring dental care into picture so for example if brushing your teeth once a day is like 12 hours time just to eating and brushing your teeth twice is like 10 hours time to eating and flossing and brushing is eight hours time retreating and then going to your dentist once in every six months is kind of doing water fasting once in a while are you going to go to your dentist every week will that improve your dental health to get your teeth really scrubbed and drilled no i mean this is exactly where we have to do some common sense the reason is you know this is where we can also go talk about reds because rats is actually an extreme form of being super conscious about your health where people exercise more eat less and then they become they also develop many psychiatric and effective disorders and neuroendocrine disorders so i guess anyone from 10 year old to 100 year old can eat within 12 hours and a lot of us can try to eat within 10 hours so that at least for half of the days or 5 days in a week we can eat within 10 hours which is like brushing your teeth twice a day and then if you want maybe once in a while it's a good idea to do even like walter longo's fasting mimicking diet four or five days of very low calorie diet once in a while water fasting for 24 hours so the idea is that there are many different ways of fasting one thing is we have to think about a lifestyle lifestyle is what when and how much we eat sleep and exercise every single day and lifestyle is very different from intervention intervention is when you do something for few days and then go back to your lifestyle so that's why your lifestyle should be say 10 hours target and once in a while if you want to do some intervention to for example if you want to reduce your inflammation because your joints are swollen and you cannot function well when you climb stairs you have pain then maybe pay attention to your sleep try to get eight to nine hours of sleep for a week around the same time try some longer fast and that may help very sound advice um coming to the end here i'm interested in your thoughts on lifespan in humans i've heard you speak about um the potential benefit of time restricted eating um reducing the the kind of incidence of cancer and cbd the the top two killers so i'm just kind of interested in big picture here um how you see this sort of affecting public health and and lifespan and the biggest challenge now is how to reduce the burden of chronic disease because if we think of any if you ask a 50 year old like you know i went to my daughter's graduation from high school and i looked around to see how many parents are there who are approaching 50 or about 50 around 50 and they look healthy and it was very depressing to see see that so now we know that nearly 50 percent of adults have pre-diabetes or diabetes 50 are hypertensive and one in three have fatty liver disease that will progress towards nas or even liver cancer at one point um there are nearly 80 million prescription written for uh acid reflux and heartburn and the millions more who just consume over the counter medication so i think those are the things that we have to tackle first because you cannot be just asking is your car going to run till the moon so which is 250 000 miles um if it if you don't change the tire if you don't change the oil at the regular time so i think timeless eating should help to reduce the bottom of chronic disease that affect almost all of us [Music] that's the first goal and then the second is which we still don't understand means we talk about longevity a lot but in reality many of the even the lavatory experiments are not done on older mice or older animals um [Music] let's accept it for the first time in human history we are living more number of years if we use females as a as a yardstick as a benchmark women are living more number of years in the post-menopausal state than in the reproductive states reproductive years and we don't have even enough research to say what will keep a mouse healthy in that old days so i guess people who say that we can do this to keep humans live for more than 100 years with one healthy lifestyle there may be a little premature i guess at the end of the day it will be combination of many things it will be of course sleep circadian sleep some physical activity um respecting your circadian rhythm by time distributing world form foundation but on top of that we also need to understand what are the hormones what are the micronutrients or the micro nutrients that we need to change at older age and combine them with this foundation of health to to live longer but in the short term i guess time restorating will help us to reduce the burden of disease and it's a huge lofty goal because in the us when somebody goes from healthy to diabetic type 2 diabetic then the annual cost of total healthcare cost goes up by 9 000 a year and if there are 94 million people who are pre-diabetic and over the next five to six years nearly 50 percent or so will slowly transition toward towards type 2 diabetes if we delay diabetes in just a million people then that's for one year that's nine billion dollar in savings and if you can delay that in 10 million or 20 million or 30 million people for x number of years then we are talking about redirecting that healthcare spending towards other things so on a microeconomic level these kind of lifestyle changes which can be scaled up at population level can move the needle to keep the nation to keep the society more healthy and then we'll think about the longevity question well said well uh sachin thank you so much this has been really really informative and i think very very empowering uh for myself and and for the listeners so i really appreciate your time and um thank you so much for coming on here and sharing and for all of the work that you've done before i get you to uh give us a bit of a rundown as to where people can find you and and information about your various books etc is there anything that you feel like we missed or that you wanted to kind of say today that we we didn't get to well i think we covered almost everything in mind that most people will find useful and thank you so much for doing this because you know we scientists are not very good in communicating our science to people who will benefit from it and thank you for being that important link between science and people who need this well thank you those are very kind words i've i've seen your ted talks so uh i beg to to differ i think you're doing a great job with the science communication as well um for folks who want to who want to read more learn more um stay in touch with with future research that you bring out where's the best place to kind of direct them well i'll be soon back to my twitter feed so i'll be active in twitter and we also have a app called my circadian clock which is available in both ios and android and that's not commercial that's entirely used for research purpose so there is no advertising there is no email storm and we are learning a lot about people's lifestyle and also what are the barriers to adopting good lifestyle which is even much more important because if we don't understand the barriers and we cannot address uh how to change the needle how to move the needle i also have a couple of books the circadian code which gives a broad understanding of circadian rhythms and the circadian diabetes code which came out last year which is more focused on glucose control and its complications um at our website mycadiumclog.org also has a lot of blogs and based on stories and of course we our team is involved in many parallel research going on and almost in every couple of months we have something new coming out and those are all on our website okay well let's uh let's stay in touch and i'm sure i speak on behalf of all of the listeners we'd love to have you back on and learn more from you as future studies are published thank you so much sachin thank you have a perfect circadian day thank you for joining me for this episode and your interest in science-based conversation i hope you enjoyed it and found the information covered interesting and instructive if you did and you'd like to show your support for the show please subscribe to our youtube channel where you can stay up to date with new episodes and watch them in video format yes the full length videos please also consider subscribing to the show on the spotify and or apple podcast app wherever you enjoy listening to podcasts you can also leave a review on apple or spotify again a great way to support the show and make our content more discoverable for others to enjoy and learn from if you have any comments about the episodes suggestions for future episodes including guests you'd like to see on the show or questions that you'd like to have answered please leave those in the comments section on youtube i myself and my team will take note of these comments when planning future episodes finally the best way to support the show and receive discounts on products we love is by checking out our sponsors at theproof.com forward slash friends enjoy your week stay well and i look forward to catching you in the next episode

Channel: The Proof with Simon Hill

Views: 147,361

Keywords: simon hill, science, nutrition, evidence, facts, diet, how to, vegan, plant based, healthy living, wellness, podcast, conversation, the proof, the proof podcast, plant proof, health, the proof with simon hill, fitness

Id: uGBgcYBwjvA

Length: 107min 8sec (6428 seconds)

Published: Mon Aug 15 2022