I read 4 Longevity Books so you don't have to! - Introduction and Ep 1: Sleep Science

Added: 2026-05-12

[00:00:00]I read these four longevity books and hundreds of the underlying scientific publications so you don't have to. I'm Dr. Venai Prasad and you're listening to Medicine Unpacked.

[00:00:10]In the next few episodes, I'm going to walk through four books on longevity science. I'm going to go through the claims they make and what's the evidence underlying those claims. I'm very interested in what they have in common and when they differ. And we're going to praise the evidence for all of those in this series. The four books I read span the gamut. We have a professor and provost at an Ivy League university all the way to concierge medicine and functional medicine doctors. So we get the range and breadth of opinion. By no means is my list exhaustive, but I hope to capture the range of voices in this space. And then whenever the authors cite a reference that I think is of sufficient interest, I dove deep, read that paper and usually a half dozen of the related papers on the topic. And that's the framework with which I approach this topic. We have four big books. I mean these were often international bestsellers. They include Eat Your Ice Cream by Dr. Zeke Emanuel, Super Agers by Dr. Eric Toppel, Outlive by Dr. Peter Aia, and Young Forever by Dr. Mark Heyman. And we're going to go through these books and the underlying claims in this series. Just a few of the topics we're going to cover is sleep.

[00:01:19]That's what I'm going to include in this video. Then we're going to go on and get into nutrition science and exercise science. We're going to talk about cancer screening. We're going to talk about what blood work do you need. We're going to talk about cholesterol management, cholesterol medications. I'm going to do a video on some very odd things that were mentioned in these books, as well as a different video, I think, on things they didn't mention, curious things that they omitted. And finally, I'm going to do a video on blue zones, regions of the world where people live on average longer than the average person, and centinarians, those individuals who happen to make it to 100 years of age. What can we learn by restricting our search and analysis to these cohorts of people? I'll talk about the evidentiary challenges with such analyses.

[00:02:03]Why longevity? Why is my first video back on longevity science? Well, the simple answer is that we all want to live as long and as well as possible. At the same time, we crave new ideas, new suggestions for how we can do that, but we also want to make sure that what we're doing is evidence-based. And in this video series, I'm going to try to do all that for you, try to put together these recommendations, show where the commonalities are, and show what the underlying evidence is or isn't. A couple disclaimers. What will I focus on in this series? I'm very interested in advice and recommendation for healthy people. As a physician, as a oncologist, as a doctor, I'm also interested in how you treat people who are sick, who feel unwell. But that's not the topic of this video series. We're interested in longevity and longevity advice given to healthy people out there who may be reading these books. So, as much of an enthusiast I am for CARTT therapy, CARTT therapy primarily used for hematological malignancies and also now some non-malignant indications, you can see our annals paper on that. I'm not going to include that in this video series because we're really talking about healthy people and living longer and living better and not how you treat disease, which is a separate category of medicine. I'm also interested very much in modifiable behaviors, exposures, and things that you can change. So, I want to know if you're sleeping 6 hours, should you sleep 8 hours? If you're doing two sets of curls, should you do the third set? Things that you can modify. As a doctor, I'm interested in genetics and genomics. But for this video series, I'm interested in it in so far as it can be altered or changed. So, what's modifiable is within scope.

[00:03:40]What's not modifiable is out of scope.

[00:03:42]And there are lots of things that are out of scope that we can't change that we're born with and those won't be included in this video in so far as there's no way to alter those circumstances. If you ask a group of general internists what you should do to live longer and live better, they'd give you a list that sounds like this. Sleep well, eat healthy foods, and keep your weight down. Don't drink too much. Don't smoke. Stay active. Have a good sex life. Enjoy the company of other people.

[00:04:09]and then don't do silly things like drugs or ride a motorcycle or become a recluse. Now, if you give me a list like that, I want to say that's stuff that we broadly agree on, but you're not going to make a book out of that. And what interests me in these four books is how you make a book out of it. This is broad advice that we all think is generally acceptable. But in many cases, it begs the question. And I'm very much interested in specifics and not benalities. So, if you say something like eat healthy, well, begs all the questions, doesn't it? What is healthy?

[00:04:38]What foods are healthy? How much is healthy? You should do more exercise.

[00:04:41]Well, well, what kind of exercise? When should I do it? How much should I do of it? So, I'm not interested in those kinds of benalities. Don't drink too much. How much is too much? I'm interested in specific recommendations.

[00:04:52]And these books abound with that. So, what are specific recommendations? Let me give you a few examples. Introduce yourself to a new person each day.

[00:05:01]Perhaps in the library or the coffee shop. Take a multivitamin. I like that recommendation. Well, I'm not sure I like it. in terms of the evidentiary base, but I like it because it's something we can appraise. Lift weights three times a day, three times a week.

[00:05:15]Do three sets of 10 reps. Okay, I like that. That's starting to get quite granular. We can appraise that. Get a mammogram when you're 45. That's something you can appraise. And we'll talk about that in cancer screening. If the author says they do something, the author says, "I like to fast for 24 hours or I like to wear a loaded rucks sack and walk around my neighborhood," I'm going to assume for the sake of this video series that that's a tacit recommendation. They're not just saying that they like to do that. They're saying that that's a good thing that one should do. And so I'm going to treat those recommendations as if they're generalized to other people. That's just one of the conventions of this series.

[00:05:50]Adherence is a part of the recommendation. Now, this is a very big idea that really needs to be thought of, which is that how often and how well people stick with your advice is a part of your advice. It's baked into your advice. Take the absurd case that you're somebody who's overweight, you want to lose weight, you come to me, say, "What kind of diet should I follow?" And I say, "You should follow the just don't eat anything diet. Just literally don't eat anything at all. Just drink water and I will monitor your blood levels.

[00:06:18]And if you get your electrolytes out of whack, I'll give you some IV fluids, but don't eat anything at all. We will put you on a 100% fasting diet. Well, guess what? You're going to lose weight. But here's the problem. That would have no real world adherence. Nobody can be able to sustain that in the real world. It's a ludicrous diet. When we go to the doctor and we ask, "What's a good diet?"

[00:06:37]What we're really asking is, "What's something that I can do and sustain?

[00:06:42]What's a diet I can live with? What's a diet that I can tolerate and thrive under? And that's what goes into these recommendations. So, I'll give you a few examples. Getting a new dog or cat. So, pet ownership in a number of studies is associated with longer survival. Now, do I believe that's causal? Do I think that owning the pet makes you live longer or that the types of people who own pets are also otherwise meant to live longer?

[00:07:07]You know, I tend to fall in the latter category, but I love dogs and so I want to believe I want to believe that owning a dog makes me live longer. But my first question when I approach that does owning a dog make you live longer, should I go get a dog? My first question is, well, of a hundred people who go out and get a new dog, how many of them still have the dog a week later, a month later, or a year later? And it turns out on this question, there's some data on adherence. The ASPCA keeps statistics and they say according to one survey and you know all the usual caveats applied to the method of their survey but they say 90% of people retain a dog one year later 85% of people retain a cat. So I'm happy to concede that I believe that getting a new pet which interestingly none of the books actually advocates for. I believe getting a new pet is something with extremely high adherence.

[00:07:55]What about that recommendation?

[00:07:56]Introduce yourself to one new person each day. Boy, doesn't that sound nice?

[00:08:01]we're out there in the real world and you introduce yourself to one new person each day. I'm sure they're going to love it. Well, I have doubts about that adherence. So, I looked in the literature. There's no published study of how often people continue to do that a week, a month, a year later. But my common sense and intuition is probably the same as yours, which is that's going to die off very quick. You're not going to be able to sustain introducing yourself to a new person each day, especially with all the awkward interactions that come afterwards. And so, you're not going to be able to do that. So what's my rule of thumb here?

[00:08:33]My rule of thumb here isn't if it has high adherence, it's got to work and if it has low adherence, it has to fail.

[00:08:40]It's that if it has low adherence, primmaaccia, it's hard to believe it can improve your outcomes, your survival. If it has high adherence, well, it may or may not work, but at least that's a prerequisite to consider it seriously.

[00:08:53]So there are recommendations in these books which I think have extremely high adherence and there's some with adherence that's going to be so low it's not even worth talking about because if you recommend to a person in front of you or hundreds of people in front of you a recommendation with very low adherence. Nobody's doing it a year later. You need to go back to the drawing board. You need to think about a different way to get people to do that.

[00:09:14]Perhaps incentives perhaps structure in their life. You can't just say use your breath in those cases. So in my mind, adherence is a fundamental part. And throughout this video series, I'm going to be talking about the adherence or possible adherence of an intervention.

[00:09:28]Right recommendation, but bad reason, you know. So what if they recommend the right thing, but the reason is dubious.

[00:09:34]So if they say something like you should do squats and leg exercises so that you're less likely to fall and have a hip fracture. Well, right off the bat, I think that's entirely plausible. We can consider that leg exercise strengthen the legs and you're less likely to fall, have a hip fracture. If they say, "Do bicep curls." I say, "Well, that's not a bad idea. It's doing some bicep curls sounds good to me, but do it in order to prevent Alzheimer's disease." Well, then I'm going to say, "Oh, boy. Is that the right reason to do bicep curls for the Alzheimer's disease benefit? What's the evidence for that?" So, that's going to be something we talk about. Right recommendation, wrong reason. What about right recommendation, right reason, and wrong evidence? So what if they were to say something like eating a handful of nuts is good for you. It's good for your longevity. I'm actually probably willing to concede that handful of nuts is good for you and it might be good for your longevity. But then what if they say we find in this observational study it lowers the risk of cardiovascular disease by 20%. Well, the moment you make that very specific claim, a 20% one in five reduction in cardiovascular disease in a relative risk sense, I'm starting to wonder if that's a robust study. are the types of people in your study who happen to eat and sustain the habit of a handful of nuts week over week over week without falter or fail the same types of people who never eat nuts or rarely eat nuts. I'm not sure about that. Okay, so I don't know if that's going to be a robust piece of evidence to support what I think is a generally harmless comment that you should eat some handful of nuts. Okay, here's a big one. Here's a thorny issue that extends across all of the books. We need to draw a distinction between avoiding untimely death, in other words, living to 70 or 80 or 90 instead of dying in 40 or 50 or 60 from complications of diabetes or cardiovascular disease versus life extension, which means instead of living to 88, you live to 108 or 128 or 148.

[00:11:32]There are even people in the longevity space who say I want to live so long there continues to be a new medical advance that keeps coming along to keep me going such that I don't die at all.

[00:11:42]So there are people who hold this idea that they'll never die at all. Well, I'm very interested in knowing whether or not these recommendations are about avoiding untimely death or truly longevity. And I think you are too because I think many of us know and I think that internist has said the sorts of general things that we think go into avoiding untimely death. But what actually gets us to have longer lifespans? In one video in this series, I'm going to talk about the science of lifespan extension and what we know and don't know about that field. So, with that prelude, I'm going to talk about sleep science. I'm going to give you just a little bit of a flavor of what this video series is going to be about, and I'm going to pick the least controversial topic, which is sleep. And spoiler alert, these books all tend to broadly agree on sleep, which I agree with too, which is most Americans, you don't sleep enough. You don't sleep enough. So, all of these books are interested in sleep. They all talk about it, but the things we're going to talk about are how much should you sleep?

[00:12:38]Should you sleep at the same time every day? Should you use sleep aids? And these, I think, are sort of the key question. And what should you do about the room you sleep in? These are the key questions.

[00:12:48]There's widespread agreement across these four books that most Americans don't sleep enough. They all have slightly different recommendations for how much to sleep, which we'll get into.

[00:12:56]But interesting to me that three of the books actually begin with an anecdote.

[00:13:00]This is eat your ice cream, outlive, and young forever about how the author didn't get enough sleep when they were young and they thought nothing of it.

[00:13:06]These authors were arrogant and they thought you'll sleep when you die. As they get older, they wise up and realize sleep is important. Just fascinating to me how many of these books have the same sort of anecdote. Now, the fact that less than 7 hours is bad for you is shown across many, many studies. I'm going to talk about that a little bit here, but exactly how much sleep you should get is something where they defer a little bit. So, I delved into one of the papers cited in the books and some of the underlying papers. This comes from the UK biioank which is a longitudinal cohort study of tens of thousands hundreds of thousands of participants where genomic information is measured alongside a host of other health variable information. There are subcohorts where people get brain scans or complete certain types of questionnaires including on sleep. And this is one of their seinal papers that comes out in a nature family journal.

[00:13:56]And what it shows very clearly is that there is a relationship in this observational data set between how much sleep people report and their health outcomes and performance outcomes. Shown on the screen is cognition and mental health, depression and mania and the different age groups for one of the figures. And it basically shows what we call a J-shaped curve. A J-shaped curve in epidemiology means that there is bad outcomes before a certain point and bad outcomes past that point. There's a sweet spot of where you should be. And the sweet spot for all of these things, cognition, mental health, depression, mania, looks to be between seven and eight hours. If you sleep between seven and eight hours, you got the best cognition, the best mental health, the least depression, the least mania. But is that right? Is 7 to 8 hours the sweet spot? If you go up to 9 and 10 hours, things start to get worse. Is that correct? Well, in order to appraise these data, you should know exactly how the question is asked. And I did that. I dove into this paper and I found and thanks to the nature family of journals, it wasn't easy to find. They bury the methods in the back. I found the precise question asked. So, let's take a look.

[00:15:03]Sleep duration was recorded through touchscreen questionnaires, including questions such as about how many hours of sleep do you get every 24 hours?

[00:15:10]Please include naps. I think it's completely vital the way they ask the question. It's a very important distinction is how you ask the question.

[00:15:18]And here they're including naps in the variable on the x-axis. So what am I to conclude among the people who sleep 9 10 11 hours in this data set once you get over 8 hours? Are you getting all that sleep at the same time overnight? I'm happen to think there might be a difference between getting 9 hours of sleep consecutively at night and getting 6 hours and then taking a 3-hour nap.

[00:15:43]All things being equal, the type of person who will sleep six hours and get a three-hour nap might be somebody who's more likely to have a chronic medical illness. They might be more likely to be on disability, less likely to be in the workforce. How can they have the ability to take a three-hour nap? But both of those people are being coded exactly the same in this data set. And thus, I have a lot of problems with this data set with concluding that sleeping more than eight hours is bad for you. I'm happy to concede that this data set and every data set I've ever seen shows that sleeping less is terrible for you. And I think not only do these data show that, but a host of short-term physiologic endpoint data and performance data show that. But whether or not 8 7 hours is the sweet spot, I think should be called into question. And I'm not the only one who thinks that. One of these books actually was a bit more open-minded than the others and conceded that higher amounts of sleep might be better for some individuals. In the Outlive book by Dr. Tia, he cites a study of Stanford basketball players who at baseline were sleeping 7.8 hours a night, which I think is more than the average American and they were encouraged to increase that sleep to 10.4 hours and they did that and by doing that they actually had much better performance on the court. He also cites the example of LeBron James who famously says he likes to sleep between 9 and 10 hours a day, maybe even toss a nap on. He says you want to sleep so much that when you wake up, you're ready to go and get on with your day.

[00:17:10]And so I'm entirely open-minded to the idea that the right amount of sleep might be more for some individuals, particularly those who are highle performers or want to be high level performers. I'm skeptical of data like that UK bioank data that shows bad outcomes because I think that includes people who are chronically taking naps and may have other health problems. And one hint in that graph is that we see slightly different outcomes among individuals who are still of workforce ages and those who are past workforce ages. So eat your ice cream. It says seven to eight hours is ideal. Super aers 7 to eight hours and is actually very critical of sleeping more than that. But outlive I think is a bit open-minded and I think that's the position I fall in. Now, how would you study sleep science if you really wanted to study it better? And believe me, it needs a lot better study. I think the current evidentiary base is very poor, pretty inadequate. Well, I think the first thing you would do is try to get a sense of how much do Americans actually sleep. And I found this nice article in The Economist that captures that. It shows the duration of sleep by year, by calendar year among men and women. Looks like women are sleeping more than men.

[00:18:16]and among age which shows that people in the workforce ages are the ones who are getting the least amount of sleep probably because they got to wake up and go to work and the average I think is quite low.

[00:18:27]I'm only sleeping as shown here in this histogram plot of how many hours people are sleeping and you can see it's all over the place. So how would you study this if you were a researcher funded by the NIH or other non-conlicted groups?

[00:18:38]How would you study this? And here's how I propose you would study the sleep question. I think you got to draw a distinction between people who are already sleeping 7 to 8 hours and people who sleep less than 7 hours. I might start with the following. There's a separate study for people who sleep between 5 and 7 hours a night. We're going to take those people and we're going to randomize them and put them in three groups. One group just stay the course. You do what you're doing. The next group of that of that group of people, we randomize them to the second cohort where we say, "Hey, increase your sleep by 1 hour." And the third group increase it by two hours. And the first thing we do is we follow them a month later, uh two months later, uh 6 months later, a year later, and just see what's the adherence. And if it turns out that by recommending more sleep, you've actually not achieved any additional sleep. You need to stop right there. Go back to the drawing board. You have a by telling people to sleep more, you've done nothing for them. So you need to rethink how you can get them to sleep more. Your intervention has failed. Your recommendation doesn't work in the real world practically. But let's say it does work. And I suspect there'll be some modest increase in sleep in these two groups. I'm not sure there'll be much of a difference between the add one and add two-hour group. Then I think you want to measure short-term end points, blood glucose, A1C, cortisol levels, things that um give you a clue of how their body is adapting to that short-term change. Then I think you want to measure cognition, performance on tests, how well they do at their job. And then I think you want to look at sort of the longer term outcomes, cardiovascular outcomes, stroke outcomes, and finally perhaps even mortality. But you want to start with those first few outcomes.

[00:20:10]Now, I think you can do a different study for people who sleep between 7 and 8 hours. You could say something like, "Boy, we're going to take you and have you do add one, add two, maybe even sleep less, take 1 hour away." You could take people between 8 and 9 hours and do the same thing. I think in these high levels of sleep, if they are in fact delotterious by asking them to sleep one hour less, maybe you'll see an improvement in their performance and cognition and and cardiovascular outcomes. I think it's really important that the studies draw a distinction between taking a nap and not taking a nap. Now, some people in the comment section will say, "Oh, we've done studies like this." Well, the studies that have been done on this topic uh appear to be quite low sample size, quite low follow-up, uh quite poor for following adherence and don't really answer the question in a way we need.

[00:21:00]This is such an important question.

[00:21:01]People are so interested in it. We're talking about a sample size. I think of many thousands, perhaps tens of thousands of people in order to answer this question. And I think it's worth it from a societal level. I completely believe that better understanding how much people sleep and the incentives that go around that space is worth it.

[00:21:15]And all of these authors agree and if we do care about living longer and living better, I think we should prioritize such research.

[00:21:22]So what are my takeaways of looking at these books? I think they are broadly in agreement and people who try to say they disagree are missing the point. Missing the forest for the trees. They all agree and I'm happy to agree that short less than 6 hours of disrupted and poor sleep may increase untimely death and is a sign of a chronic health issue. Perhaps sleep should be optimized to subjectively feeling good and performance in the absence of credible data. There's a posity of good randomized studies and good sleep advice. So, we desperately need funding for that. And I think if you did sleep 8 9 or 10 hours, you go from 6 hours to 8 9 10 hours. I'm happy to believe that you're less likely to avoid untimely death. But I'm incredibly skeptical about whether or not you're going to live to 120 or 140. And so, in other words, I put this whole category of interventions in the avoid untimely death bucket and not the life extension bucket. And so, I'm broadly in agreement with these books. I think this is sensible advice. I think it's the same advice my mother would give me. Um, a few more pearls. Using alcohol to fall asleep is suboptimal. Sleep medications generally don't work. Their effect sizes are almost marginal or minuscule. They may help you fall asleep a few minutes sooner and but that sleep may be more uh disrupted. Now, some of the recommendations in these books piqu my interest because they actually do have quite high adherence. Here's one of them. Take a little bit of black tape, black electrical tape, and cover up all those little tiny light emmitting diodes and all of your electronic equipment in your bedroom. Now, that's an intervention that well, I'm not sure you're going to live longer as a result.

[00:22:59]I'm not even sure you're going to have a deeper night's sleep, but I'm certainly sure that if you do that, you're gonna have high adherence three months or six months later. The only way to break that is if the tape peels off or if you buy new electronic devices. So, I think that's a high adherence recommendation.

[00:23:13]Another recommendation a couple of the books say is don't look at your phone before you fall asleep. Well, that's sensible advice, but that's what I call a poor adherence a poor adherence uh bit of advice. I don't think there's anyone out there who is thinking to themselves, "Boy, if only somebody told me not to look at my phone before I go to sleep, I'll live to 120." Because the truth is, we've all heard that advice and we've all disregarded it because we've got stuff to look at on the phone and I think that's going to have poor adherence. So, I wouldn't have included that in any of the books. Without adherence, it's a non-starter. You're not going to live longer, live better.

[00:23:47]What about sleeping at the same time each day? Again, the UK Bioank has a study. This was published in uh e life.

[00:23:54]I believe I published one paper in there many years ago. It's called sleep regularity and mortality a prospective analysis of UK bioank. And they look at something called the sleep regularity index. And they again find this sort of curve. Um here it's a curve that only goes in one direction. The more regular the better. What is sleep regularity index? It's an index that goes from 0 to 100. 100 means you sleep at exactly the same minutes of the day. Day to day.

[00:24:20]7:00 p.m. to 6:00 a.m. exactly the same minutes, for instance, or 10 new midnight to 4:00 a.m. exactly the same minutes. Doesn't matter how long, it has to be the same minutes. Whereas zero means you sleep at 100% different minutes. You're sleeping 8:00 p.m. to midnight one night, then midnight to 4:00 a.m. That's a zero. And as you can see, most people are something in between that. They're in the 30s, 40s, 50s, 60s,7s. And what this shows is whether you look at all cause mortality, cardiovascular disease mortality, cancer mortality, you broadly see a comparable finding which is that people who sleep in the same hours of the day, they tend to do better than those who have sleep that's erratic. Well, what do I do with this paper? As a researcher, I'm not sure what to think about these PE paper.

[00:25:03]Um, the types of people in who can sleep at the exact same hours of the night and those who sleep in different periods of time are very different people. We're comparing shift workers to people with a regular schedule, people whose kids have a lot of events versus people who may not have kids. I think it's completely disperate groups of people. The kinds of resources, um, self-discipline, uh, health recognition it takes to sleep at exactly the same hours every day um, is fundamentally different than somebody who can't manage that. And I think this graphic is not exactly telling us about sleep per se, but the sorts of person who is so regimented in their sleep that they can sleep at the same time. So I put almost no stock in such analyses.

[00:25:45]Sleep trackers. Sleep trackers was an interesting topic that these books kind of disagree on. Uh couple of the books said it can cause anxiety and be inaccurate. Um I think there's no one who disagrees it can be inaccurate who's ever used it. Uh Outlive says some find it anxietyprovoking, but I find it helpful. which is a I find it helpful recommendation.

[00:26:05]To me, the claim that you shouldn't do it because it can cause anxiety is a bit flawed. Uh by that logic, don't get on the bathroom scale or look in the mirror. Uh you might not like what you see. So, I I don't I don't necessarily understand. Don't look at it because it can cause anxiety. A couple of the books point to a study that's in the journal of sleep research in 2018. Very small study of 60 participants. They all wore sleep trackers. Then irrespective of how much they slept, they were randomized to being told you slept great versus you slept poorly. And it turns out being told you sleep poorly, even if you sleep the exact same versus told you sleep great, you actually feel less rested if you are told you slept poorly. So their argument is, boy, the sleep tracker, you wake up, you slept great, and tells you you slept poorly, suddenly you start feeling tired. It's not good. It's a harmful intervention. But I have a different conclusion from this research.

[00:26:56]In my mind, what's so powerful about this research is it shows the powerful power of suggestion right when you wake up. The moment you wake up, the first thing you look at can affect how you feel like you slept, like reading the tracker. But what if you wake up on a Sunday morning and the light is streaming in and hitting the carpet? Um the the dog that you purchased to increase your longevity is sitting right there looking up at you. Uh the birds are chirping. Uh the sky is full of radiant sunlight. Boy, don't you feel like you slept great? or you wake up, it's a cloudy day, you hear something crash in the other room, you hear shouting down the hall, "Boy, didn't you sleep poorly?" So, in my mind, I guess to me, this kind of study calls into question whether or not our subjective perception of how well we slept is a faithful c a faithful arbiter of how well we actually slept. So, I think these studies should not just include subjective perceptions of how you slept, but perhaps even more objective metrics like cognition and performance. That's what I would be interested in seeing.

[00:27:53]So, in my mind, this doesn't invalidate or discredit a sleep tracker. I tend to be closer to the if you find it useful, you should use it point of view, but this does suggest the challenges with measuring sleep quality in this space. I also think that sleep trackers could be a motivating tool and we could imagine separate randomized studies where people are given a tracker or not given a tracker or given multiple trackers and asked to see the concordance between the trackers, whether or not having a tracker makes them more likely to sleep.

[00:28:20]You could build that into the first study I described.

[00:28:24]All right, so that's an introduction to this topic. We're going to be talking about longevity science. Sleep, I think, is a great one to start with. There's not a lot of debate. 7 8 hours broadly agreed on. What about 9 10? I think there's some disagreement. I tend to be more open-minded that that might actually be beneficial as long as it's not a nap because you are sleeping poorly at night or chronically ill. I think a lot of the sleep research is of poor quality. We do need some prospective randomization in the space to improve the research quality.

[00:28:53]Adherence, I think, is a key a key part of this. You want to know whether or not your recommendations stick. Putting uh tape on your LED diodes, I'm not sure you're going to live longer, but I am sure that tape going to stick. Uh looking at your phone at night, I wouldn't tell somebody that because it ain't going to make them change their behavior. That's just my two cents. So, in this video series, we're going to talk about all these topics, so much more. Or if you have suggestions, drop them in the comment section.