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We estimate that approximately eighty percent of people who have sleep amnia are undiagnosed.
That's crazy. Please welcome Maria.
What is good sleep and should we just use the metric of quanta? The range is somewhere between seven to nine hours. Once you start to get less, the shorter your sleep, the shorter your life. When sleep is abundant, all of a sudden, your appetite hormones are rebalanced, so you naturally stop eating as much as you wanted to the weight starts to come off you, and you're simply sleeping the weight off yourself.
It sounds like you're saying that sleep is that number one domino that then naturally helps all of the others.
If you are not sleeping in harmony with your natural biological sort of rhythm, then your sleep quantity and quality is worse. Regularity maybe as if not more important than quantity. And I would say to anyone listening, if you're going to do anything with this podcast, just do this one thing.
The number one health and wellness podcast, jayd. Hey, everyone, welcome back to On Purpose, the place you to become the happier, healthier, and more healed three of the most important priorities in our lives. Today's guest is someone that I've been wanting to speak to for a long long time about a subject that I believe is critical to our health, happiness, and healing. Today I get to speak to Matthew Walker, a sleep expert, scientist, author, podcast host,
and professor of neuroscience at UC Berkeley. Translated in forty different languages, his best selling book Why We Sleep explores the goal to reunite humanity with sleep Matthew's work has shaped public understanding of how a simple thing likes sleep, impacts memory, aging and disease prevention. Please welcome to On Purpose, Matthew Walker. Matt it's great to have you.
Here, Jay, that absolute pleasure to be here. Thank you so much for having me and giving me the opportunity to speak the voice of sleep.
I love it. I love it. Matthew. Let's dive straight in because there's so much to decipher with you, and I want to start by asking you how much sleep do we actually need?
Yeah, it's an interesting question, and there is definitely a range, you know, I think there is, and perhaps even populated by idiots like me that there was this magical eight hour number that was you know, necessary and get anything less and there's doom and gloom. The range is somewhere between seven to nine hours for the average adult. And what we certainly know is that once you start to get less than seven hours of sleep, we can measure impermit in both your brain performance as well as your
body metrics. So there is a range. But in some ways it's also a question of what is good sleep and should we just use the metric of quantity and we absolutely should because using that sweet spot of seven to nine hours, it looks as though the shorter your sleep, the shorter your life. Short sleep predicts all cause mortality,
so duration total man is necessary. But if you actually look at the science, what is good sleep can be really answered by a four part equation that in my mind, there are really sort of four macros of good sleep three macros of food, fat, protein, carbohydrate for sleep four macros and you can remember it by the acronym QQRT, and it stands for quantity, quality, regularity, and timing. So quantity, you're absolutely right, somewhere between seven and nine is that fit.
Quality is about the continuity of your sleep. Is your sleep fragmented and littered with all of these awakenings and you're awake for a lot of the night, that's not good quality of sleep. So you could be in bed for nine and a half hours and still get seven hours of sleep, but you're spending two and a half hours of time awake. That's not good quality of sleep. Then we can speak about regularity going to bed at the same time, waking up at the same time. It
sounds very benign. Well, do I really have to worry about regularity. There's a great study and they looked at regularity and quantity. Both of them predicted all cause mortality. So if you're very regular and you get that seven to nine hours of sleep, you have the lowest mortality risk. But then because they had these two measures in the same individuals, they put them in the same statistical analysis and did the sort of Coke Pepsi challenge between the two.
What they found is that regularity beat out quantity in terms of predicting your mortality, meaning regularity maybe as if not more important than quantity. Now you've got to get both. But so QQR quantity quality regularity timing. Timing sounds like regularity, and you think, well, what's the difference. Timing is about your Krono type? Are you a morning type, evening type, or a neutral. And it turns out, by the way, that if you're a night out, it's not your fault.
It is genetically a large genetically determined There are at least twenty two different genes that dictate whether you want to be a morning person or an evening person. So you don't get the choice. It's gifted to you at birth. And what we find is that if you are not sleeping in harmony with your natural biological sort of rhythm, then your sleep quantity and quality is worse. So let's just say we take someone who goes to bed at
ten pm and wakes up at six am. Well, if you're a slight morning type, that's actually quite ideal for you. But if you're an evening type who likes to go to bed at two am and maybe wake up at ten am, then it's the same eight hour window that they're getting. But if the night our two am to ten am is forced to sleep from ten pm to six am still eight hours, the quality of their sleep that they get will no word be as sufficient as
the morning type. So some people will come to our sleep center and say, I have terrible sleep onset insomnia. I get into bed and I'm awake for the first two hours, and then I fall asleep, and we do a CRONA type assessment, which is morning type evening type. And by the way, people can do this online very quickly. Right now. You can just type into Google m e Q test me EQ. It stands for Morning this Evening this questionnaire and it fits very well with your genetics.
Takes about three minutes when we do this type of assessment with them, what we realize is that they don't have insomnia. They're a night owl, but they're trying to sleep like a morning type. And so when you sleep sort of against your natural biological predilection, your sleep is not going to be as good as it could be if you move yourself closer to your natural, innate biological tendency. Does that make sense? So those to me would be yeah, yeah, can you shift your sleep?
If people want to have Someone said Matt, that made so much sense. I've been a night on my whole life, but I just feel like I should be trying to sleep early and wake up earlier. It would be better for my partner, would be better for my lifestyle, would better for my kids. Whatever it is. Can you shift your type?
It's a really good question. I get asked that a lot because in some ways, what I'm talking about is the ideal world, and drum roll, none of us live in the ideal world. We live in this thing called the real world. So you know, stop your fancy sleep science and tell me just you know, can that change? There was a study done in by a group in Australia and they took I think it was about eleven different things that you had to do as a night owl to see if they could drag you back so
you felt more capable of going to sleep earlier. And it was things like, as soon as you wake up, eat a large breakfast, gon't get daylight first thing, exercise before midday, do not nap, take an earlier lunch, don't
nap again in the afternoon. In the afternoon, start to get as much darkness as you can, meaning put shades on if you're going to go outside in the evening, make sure that you eat at least three hours before you expect to go to bed, and then try to push your sort of alarm clock the next morning by
about one to two hours. And they collected all of these different sort of regiments and sure enough they were able to drag people back by a little bit over one hour, which sounds great, but the problem is these were extreme night owls who would prefer to go to sleep at maybe let's say one thirty am. That means they're still having to go to bed biologically at twelve thirty am. It's not the nine to thirty PM or
the ten PM that you would prefer. And imagine trying to capitulate and adhere to that regiment for the rest of your life. So there is some wiggle room. It seems that you can sort of manipulate. But in truth, I think what we have to try and do as best we can is to say, how can I align myself better with my biology. When you fight biology, you normally lose, and the way you know you've lost is
disease and sickness. And that's what we see with night owls who are sort of trying to sleep against their tendency. That said, though, is there a way that you can I mean, hack isn't the right word, but there are ways that you can try to help yourself. So think about what you do in the morning that takes time. So is it that you sort of, you know, make the coffee, you put the coffee and the coffee pot, You get your clothes ready for work, you pack your
bag for the gym after work. All of these things you can do ahead of time the night before. To take that fifteen minutes of added time the next morning and say, allow yourself to sleep a little bit later, see at least getting closer to your natural tendency. Then go to the front end of sleep and say, what is it that I do in the last fifteen minutes
before I go to bed? Well, I usually sort of maybe I take a shower, maybe I change for bed, Maybe you know, I brush my teeth, maybe some people take their makeup off, whatever it is, Set an alarm two hours before bed, do all of those things, and then right before you go to bed, when that alarm goes off, the to bed alarm, all you do is
get up and you go straight to bed. So you've saved yourself fifteen minutes on the front end, So you can go to bed fifteen minutes sort of later, and you can wake up fifteen minutes later, but you're not necessarily having to go to work any later. So does that make some sense? So you can try to short sort of thin slice some of that a little bit.
Yeah, absolutely. If you're someone who's waking up tired regularly, Like right now, someone's listening and they're just like Jane Matt, I wake up every day and I'm just tired. Yeah, and I'm trying to get the right amount of sleep, but I'm still figuring it out. Where do I start? What would you encourage them to look.
At so I think the first thing, let's go back to the four principles. Are you getting a concert seven to nine hours of time at least in bed? Next, are you trying to assess your sleep and say, am I waking up a lot throughout the night? I would say that's one of the first places I would go to. If yeah, if the If you're not feeling restored and refreshed by your sleep the next day and you're getting four hours of sleep at night, then it's obvious it's
just not the right quantity. But if you're being good and you're spending sufficient time in bed but still feeling unrefreshed and restored, we have to ask are you waking up a lot throughout the night? If you are, let's figure out why is it that you are, for example, snoring a lot throughout the night, and you have undiagnosed sleep app near and you can just download an app on your phone. I have no association with them. It's called snare lab, So snare Lab and you download it.
It records your breathing. You place the phone next to you on your bed. Then in the morning it shows you a Richter shock sort of scale throughout the night. And it quantifies your snoring into quiet, moderate, loud, and epic. And the frightening thing is you can then tap anywhere throughout the night and you can hear yourself snoring in a way that we don't. So the next thing is, let's make sure that you don't have an undiagnosed sleep disorder. Then I would say, is it a case that you're
maybe over consuming on caffeine during the day. Some people will feel completely comfortable having an espresso with dinner and they say, I fall asleep and I stay asleep. So I'm one of those. And it is genetically determined who can metabolize caffeine quickly and it has no effect. We've done studies and unfortunately, even if you do fall asleep and stay asleep, that caffeine can prevent you from going into the deepest stages of what we call deep non
rapidi movement sleep. That's where you get a lot of restoration sensation from. So maybe we need to ask how much caffeine are you taking, the dose and the timing make the poison. Try to cut yourself off after about three cups and try to stay away from caffeine at least ten to twelve hours before you expect to go to bed. The final thing I would probably say is are you also using anything in the evening to help you fall asleep? And the principal thing I'm talking about
here is alcohol. It's probably the most misunderstood sleep aid that there is out there. It's actually not a sleep aid, and it will fragment your sleep and block you from getting rapid eye movement sleep. So what we would do is we would march you through a set of environment or behavioral things. What are you doing in terms of your bed timing, are you spending a lot of time awake?
And also the things that you're taking into your body alcohol, caffeine, etc. The final thing I would say is stress and anxiety if there is one outside of skeletal pain. The principal reason that we as a society seem not to be sleeping is this role that acts of anxiety. Because, and you've spoken so eloquently about this, in this modern era, we are con instantly on reception. Very rarely do we
do reflection. And the only time now in the modern world when we do reflection is when our head hits the pillow, and that's the last time that we need to do reflection, because at that point the rolodex of anxiety starts worrying. At that point you start to ruminate. When we ruminate, we catastrophize, and then everything feels twice as bad in the dark of night than it does in the light of day. And at that point we're
dead in the water for the next two hours. So the final thing I would say is, let's speak about your mental state. So does that give you a sense of sight? The pinwheel diagnostics that we would go.
Through, we love it. I love it. I love the acronym. I love how simple and formulaic it is for us to be able to actually measure what's going wrong, and I can. I'm fortunate and very grateful and knock onward, sleep very very well and generally always have. But whenever I have had disturbances in my sl I can easily pinpoint it to something you've said. And that shows me
how great the model is. Because as someone who is lucky and fortunate enough to have great sleep, when I have been disrupted, it's always been related either to caffeine,
to stress and anxiety. I can easily draw the parallels because it's such a rare occurrence, and so I can see why and when I want to dive into each of those, let's start with sleep apnea, because I think that's something a lot of us don't actually know enough about, and so I love the fact that people can use the apps or lab as you mentioned, how many people actually struggling with sleep apnea don't even know about it? And what is actually happening if you have sleep apnea?
Yeah, two great questions. So right now, we estimate that approximately eighty percent of people who have sleep apnia are undiagnosed.
That's crazy, which, if you look.
At the numbers, is going to be a non trivial proportion of the population. And the reason it's so dangerous is because when you have sleep apna, essentially what's happening is that your airway is either partially becoming obstructed or
like a straw, it's collapsing flat entirely. Now, if it starts to become obstructed, so let's say you're sleeping on your back and the airway flaps in that airway are starting to give weight to gravity, then you'll start to get a partial blocking, a partial what we call occlusion of the airway. And that's what you hear. When you hear the sound, that's the sort of the flapping of
the partial occlusion. And then when you stop breathing entirely, at that point, the airway has completely collapsed, the straw has gone flat, and after about fifteen or twenty seconds, your brain stem registers the alarming buildup of carbon dioxide in your blood because at that point you are slowly asphyxiating, and it sends a wake up trigger up to your cortex, and then all of a sudden you hear and you gasp,
and you're awake. So imagine now we have a way that we measure these sort of occlusions and these partial collapses, and it's called the a HI score. And don't worry about this stands a fort the apnea hypot nea index. Suffice it to say that we look to see how many events like this are you having per hour of sleep, And if you were to have very mild sleep at near you may be having five, ten, fifteen of these events.
That's considered mild. Some people could have eighty of them perhaps, But let's just say you have mild sleep at near ten of these events an hour, and you're in bed for eight hours. So imagine the following scenario with undiagnosed mild sleep apna. What if I were to say tonight, I'm going to come into your bedroom, Jay, and every hour I'm going to throckle you, strangle you to the point where you actually stop breathing. And I'm going to do that ten times every hour for every one of
the eight hours. So I'm going to do that eighty times throughout the night. Do you think you're going to feel restored and refresh by a sleep the next poem? And the answer is no. But that's what Now that's hyperbolic, of course, but in some ways that's what we're facing
even with the mildest version of undiagnosed sleep apnea. That's why sleep apnea untreated is associated with a very significant increase in all cause mortality as well as increases immortality related to diabetes, to cardiovascular disease, as well as certain forms of cancer. So I think for me, it's the case of it's not only going to erode the quantity of your life, meaning your lifespan, it will certainly shorten your health span. That's what most of us are worried about,
not really our lifespan, it's our health span. None of us want to live with disease or sickness. I certainly don't want to. And I remember there was a patient that we work with with sleep apnea, and after they were treated, they were saying, well, before that, I just thought this was me at fifty seven years old. I just thought I would deteriorated with age. And I realized there was some one in there that wasn't the way
I felt. And when you treated me with sleep apnea, it was almost as though someone cognitively had wiped a fogged glass clear and finally I could see again. And so that's why I think so many people can benefit by way of just simply doing taking this app seeing
whether you snore. Also, you can do something called the stop bang questionnaire so stop all in caps, dash B A NG, and you can do it also online, and it's a very quick questionnaire, probably about two minutes, and it will evaluate your risk likelihood of having sleep apnar one of those two. If you fear that you have sleep apnea, or if you know that your partner has sleep apnre please go and get it seen to. It's a laughing about you know. We think, well, they sound
like a chainsaw, they wake the neighbors up. It's almost this thing of sort of humor. Trust me, when it comes to your health and your wellness, it is anything but a funny story when it comes to undiagnosed sleep at MEA.
Yeah, thank you so much for giving sense practical tips as to how we can check as well. And I hope everyone is listening and watching. Please go do that because the fact that eighty percent of people may not have a clue and that could be the secret behind better sleep is crazy to me that we haven't uncovered it for eighty percent of people.
That's huge, and so many downstream consequences happen when they get treated that they are typically overweight, they usually have high levels of blood sugar, of blood glucose, they typically have hypertension, high blood pressure. And what's nice is that when you were to say, okay, we've got to have you reducing your food intake, we need to stop you from eating sugar, we need to get you to the gym,
all of those things of herculean in their challenge. And people often in that state of being overweight, hypertensive, high glycemic, they just find it so hard to change. But if you treat them with sleep apnea. When sleep is abundant in good quantity and quality, which it will be when you treat them, all of a sudden, your appetite hormones are rebalanced, so you naturally stop eating as much as you want it to. The weight starts to come off you,
and you're simply sleeping the weight off yourself. It's a largely painless equation. You don't crave those sugary sort of high sugar sort of immediate hit foods, so your blood sugar comes back into control, and you're more motivated to be physically active, meaning that your cardiovascular health. So I sometimes think of sleep. You know, if you've seen one of those fancy music studios where they've got all of the dials on the mixing deck and you can move
any one of them. But sleep, to me, is that one dial all the way at the far left that if you move it, all of those other dials just kind of move up. It's the tide that floats all of our other health. And so if you get that one straight, so many things, as a manifolds like an archimedes lever, will consequently change downstream for the better. You don't even have to do anything. You just have to start sleeping better.
Let's take a short break to hear from our sponsors, and let's get back to our episode. It sounds like you're saying that sleep is that number one domino that then naturally helps all of the others. Yeah, and I've had everything that you just said. I for the past six weeks have been in LA which is rare in terms of I havn't traveled, I haven't jumped on a plane.
I've been in one place. And because of that, I've been able to really dial in on everything from sleep, working out, eating right because I've had no reason to have an error because I've been at home. And you know, when you travel, you maybe whatever right, you eat something that wasn't a hotel and whatever it maybe. I've been here for six weeks, been on a phenomenal schedule. Last week I was only gone for like four hours away, took a three hour flight to a three hour flight back.
I was gone for like four to six hours in total, and I landed back at four am, which is rare for me. I don't do that. I usually sleep by nine point thirty pm. I'm a morning person for sure, and I got back at four am. I tried to get some sleep. I probably got up at eight am because that's all I could sleep at that time. I got in a workout, but I had to tell my trainer to lower my level of workout because I was more tired than I've felt for a long time, and
I actually felt weaker. So I've been feeling really strong across the last six weeks, but I felt weaker. I was like, I don't think I can lift that much today. I'm not feeling up to it. On top of that, all my sugar cravings went through the roof that day. Interesting, Yeah, And I know, and you notice it so significantly when you're at the other end where you're like, oh wait, I haven't needed refined sugar for like weeks on end now, but this one day, all I'm craving is fats and
sugars and that's that's all I'm after. And I did give in, and I was okay about it. But but it's so interesting to feel it that abruptly and that extremely Yeah, and you're so right. I wanted the sugars, I wanted the facts I wanted. I couldn't I couldn't work out as well. All of it makes a difference.
And in some ways what's great now is the science is compelling in terms of the mechanism, such that, firstly, there are two appetite regulating hormones that called leptin and grellin. Now, Leptin is an appetite hormone that when it's released, it says, Okay, you're satisfied with your food, you don't want to eat more, you're satiated. Grellin is the opposite. It says you're not satisfied,
you're still hungry, you need to eat more. And what we find is that when we start to sort of thin slice people's sleep, and it doesn't take very much, you can sort of get maybe six hours of sleep for five nights, or five hours of sleep for four nights, all of a sudden, the hormone leptin, which says you're satisfied, you're good, you don't need to eat anymore, that starts
to decrease at one point. Well, it usually takes about four nights of somewhere between four to five hours of sleep reduction to already see those changes and see appetite behavior changes as a consequence. So it doesn't take very much and then if that wasn't bad enough, grellin the hormone that says, oh no, no, you're still hungry, please please
eat more, that goes up. So in some ways it's double jeopardy that you're getting punished twice for the same crime of insufficient sleep, once by switching off the signal of I'm full, I don't need to eat, and once again by I'm hungry and I need to eat more. Then what we have also found is that we have inside of us what we call endocannabinoids. So people have heard of sort of cannabis the way that most people have heard about it is an exogenous sort of you know,
intake of cannabis. But we have naturally occurring cannabinoids in our system called endocannabinoids. Now, many people will, let's say, know someone, of course, I'm not gonna judge anyone. We'll know someone who've said, when when I smoke weed, I get the munchies, I get hungry. That seems to be one of the consequences of these cannabinoids. Now, endocannabinoids inside of us also do the same thing. They can make
us more hungry. When you are underslept, you're naturally occurring cannabinoids, these endocannabinoids, they also increase, and that drives you to eat even more in addition to the changes in leptin and grellin. And then finally, we did a study with brain imaging where we scan people's brains with and without good sleep, looking at different food items from highly desirable
to highly healthy. When you are underslept, the rational control regions of your brain in the frontal cortex they get shut down, and these more hardonic, deep emotional brain centers that respond to rewarding pleasurable foods, they started to become much more reactive, and it set you on this path of almost obesogenic eating. You crave those sort of you know, the sugars, the chocolates, the stodgy carbohydrates, and you don't
go towards the leafy greens and the healthy nuts. You go after the pizza and sort of the salty snacks. So all of which is to say, you get this sort of conspiring both within the body and also at the level of the brain that explains exactly what you were just describing as a sort of a phenomenon. And that's why I think this You've always got to be careful with epidemiological studies where you say, okay, shorter sleep equals higher body mass index, higher chances of obesity. There
could be many things. But when you experimentally manipulate sleep and you can unpack the mechanism, then we can entertain causality for sure.
So what's you said earlier we should be in three hours before we go to bed. What's the ideal meal type three hours before we go to bed, A so that we don't get hungry just before we go to bed. Yeah, and B because I also understand that the digestive process can actually make sleeping much harder.
Yeah, and so what should we be.
Trying to digest in those three hours that keeps us full and doesn't disrupt our sleep.
Yeah, it's a really good question. And so they're the sort of the three hours. What we were trying to do is take those night owls and try to drag them back in time. But if you're not a night owl trying to sort of manipulate your sort of sleep timing, we can then just ask for anyone who's just you know, in their standard sleep regiment, when should you cut yourself off?
And it's actually a bit of a myth because there is there's this strong sentiment out there on social media you need to stop eating maybe three or four hours before bed. If you look at the data, and I did this sort of analysis of all literature, if you eat as close as sixty minutes before bed, it doesn't seem to hurt your sleep. Now if you sort of go forty five minutes or thirty minutes, then yes, it
does seem to have an impact blast radius on your sleep. Nevertheless, that's a very different question than saying, what would be beneficial to my sleep? I'm phrasing the question as at what point does it become harmful for your sleep? And the answer is you can eat up to an hour before bed and show no harm on your sleep. But that's very different than saying, but what if you'd stop eating two hours or two and a half hours, would
that have actually improved your sleep. I think what we're seeing in the data is that it's very idiosyncratic that you need to test drive it and you will know which kind of quote unquote type you are. Some people, mostly night owls, have a preference to eat late in the day or early in the evening and very little in the morning, whereas morning types like to eat sort of breakfast like a king, lunch like a prince, and dinner like a pauper. You know, they scale down. I
think it's dependent on your krona type. That said, though, the two ways that food can disrupt us. First, if we're eating high sugar content foods at night, it has a disruptive ima packed and we know this in part because it could be the not just the activating level of sort of alertness in the brain that happens with a sugar hit. It's also that simple sugars are what we call thermogenic, meaning that when we take on board sugar, it can just very gently increase our core body temperature
quite quickly. And it turns out temperature is key for sleep. We need to drop our brain and our body temperature by about one degree celsius or about two to three degrees fahrenheit to fall asleep and stay asleep. And it's the reason you will always find it easier to fall asleep in a room that's too cold than too hot. The room that's too cold. It's taking you in the
right direction for good sleep at night. So when you onboard simple sugars at night, it starts to just moderately just gently increase your core body temperature, which can disrupt your sleep. So I would say content, try to aim for. If you're going to after sort of carbohydrate, make sure that they're complex carbohydrates that release their energy in a
much slower fashion. Also, try to aim for a protein based you know, yogurt is fantastic at that point, make sure it's not, you know, highly sweetened yogurt, because then you're taking on board sugar unfortunately, So yogurt together with some kind of slow release carbohydrate is probably a fantastic approach to food. The second way though, that you can disrupt yourself above and beyond the macros of food, is that when you eat too late, particularly spicy food, it
can cause acid reflux. And that reflux is one of the other reasons that eating too close to bed will disrupt the quality of your sleep. So try to go after more of a slow release sort of protein, maybe a casine based protein, and then aim for if you're going to go after carbohydrate, just make it a smaller portion and make it a complex carbohydrate. That's probably the best recommendation.
Yeah, No, it's so important to eat about all the versions of it because I do think sometimes when you hear, oh, yeah, you can eat up until you know the last hour, you'll be fine, it's so different to well, how do I get into performing at my best and feeling at my best? And when you're already struggling with the quality of sleep, every minute kind of factor is going to
make a difference. And it's just, yeah, I'm really happy that you've gone into the detail there of like, you know, why is it that we're saying three hours or what does that look like? As I was hearing you speak, I was just thinking about just how hard it's become for people to regulate their lives and manage this. I know in some cultures it's just so natural to eat really late before you go to bed. How much does eating a late meal also push back your time of
wanting to go to sleep? Or is there no correlation there?
No, there actually is a correlation. It's a very astute observation, actually, which is you can have one type of biological chronotype predilection, but you can almost violate that biology and override some of it by creating sort of certain conditions under which it will distort your natural rhythm. One way that this rhythm is played out is the release of something called melatonin.
A melatonin is a naturally occurring hormone and it simply tells your brain and your body when it is darkness, when it is night, which is to say, melatonin helps with the timing of our sleep. And there are ways that you can artificially delay your natural melatonin release. A good one would be being exposed to too much light in the evening, too much artificial light, what I would think of as junk light. There was this concept a
while back of junk DNA. Well, I think there is something called junk light, and we get too much of it at night because we are a dark deprived society in this modern era. But there's other ways that you can delay your natural biology. And if let's say that all food was taken away, all electric light was gone, all internet service was down, and you know, the lights were out, you would naturally say to me, well, I'm
someone who would probably not get sleepy until midnight. And then all of a sudden, as I said, no food, electromagnetic pulse takes out all electricity, everything is gone. All of a sudden, you probably say, gosh, it's ten point fifteen pm. How do you feel quite sleepy? And it's because modernity, through all of its changes, light, social media, you know, sort of entertainment that were constantly exposed to.
It's dislocated us from our natural sensation of biology. Telling as it's time to sleep, most of us think that, well, I'm probably, you know, a midnight to eight am type person. When if I took you camping in the sierras for two weeks and we had all of our sort of fancy technology measuring sleep wake rhythms, and we would actually find no, you're much closer to a ten twenty to six thirty am kind of person. But modern sort of industrial life has come in the way of that and
it is modified op perception. So out to come back to your elegant insight. There are ways that we can almost contort our natural biology, one of which is things like social media, electric light. But another one is that you can just manipulate things like food timing, and that food timing will create an activating alertness sensation in the brain and the body and force you perhaps to go to bed or feel tired and two hours later than
you naturally would otherwise. So you have the way that we usually measure someone's natural sort of tendencies is we bring them into the laboratory and we say say goodbye to your friends and your family. For the next week, we take all daylight away, no windows, no nothing, and we just measure your natural biology when we separate you from everything that is in the outside world, and that way we can bring you back to your innate tendencies.
And usually there is quite the mismatch between when we interview you and say what is your natural rhythm versus when we measure you what is your biological rhythm? Those two things are often quite different.
Yeah, thank you so much. As you were talking, you mentioned melatonin, and I was thinking about, obviously the rise in melotonin gummies melatonin supplements I guess you could take before going to bed, and then you also have sleeping pills. Walk us through what's in sleeping pills versus melatonin gummies or the saw and what's your take on both.
Yeah, it's very interesting, and obviously, just being a scientist rather than a medical doctor, what I could offer you is sort of scientifically descriptive advice rather necessarily medically prescriptive advice. But melatonin has had this meteoric rise in the sleep supplement world, and now here in America where it's not regulated by the FDA. You can go into a supermarket or a grocery store and down there sort of the health food section, there is this big, sort of purple sector,
and that is the melatonin sector. Melatonin it can be useful to help regulate your circadian rhythm, and so I will use it strategically if I'm traveling. If let's say I go back home to the United Kingdom and I live just outside of San Francisco, it's eight hours ahead, so I can use it to try to trick my brain into thinking, oh, it's nighttime on the first night I arrive in the UK, when in fact, my melatonin peak is not going to arrive for at least another
eight hours because I'm still back on California's time. So, but for the most part, the way people use melatonin is night after night after night. And if you look at the studies, melatonin will only increase the speed with which you fall asleep by about two point two minutes, and it will only increase the efficiency of your sleep by about three point seven percent, which isn't that much more above and beyond placebo and the reason is because
melatonin doesn't participate in the generation of sleep. Melatonin is a little bit like the starting official at one hundred meter race. It brings all of the great sleep races to the line and begins the Great sleep race, but it doesn't participate in that sleep race. That's a whole different set of brain chemicals which we'll come onto with sleeping pills. So that's the reason that melatonin isn't a
particularly effective sleep aid. It's the reason that you will never see people being prescribed melatonin for insomnia for the most part, unless they have some kind of circadian rhythm disorder. So I would say, if you're using melatonin for the purposes of improving the speed with which you fall asleep or the generation of sleep, it may be a placebo effect. And by the way, the placebo effect is the most reliable effect in all pharmacology. So maybe no, no foul.
The only other caveats I would offer with melotonin first, because it's not regulated here by the FDA, you don't know the purity. And there was a great study that's been replicated and they looked at I think it was about twenty different vendors of melatonin, and they sampled what was inside of the pill based on what they said on the bottle versus what was actually in the pill. It ranged from about eighty percent less than what it said to four hundred and sixty percent more than what
it stated on the label. So it's a bit of a wild west. You don't quite know what you're getting when you take this need. Yeah, so you've got to, I would say, be a little bit careful. For the most part. Melotonin is largely in an at compound anyway, so we don't need to get sort of, you know, too phosphorylated about it.
What's your take on the fact that when we're taking these I guess artificial supplements of melotonin, that it depletes our body's ability to make it and regulate it at the right times that we actually need.
Yeah, And that's another critical question, and that's one of the fears that we have. I think the data we don't have right now to say one way or the other. But if you think about, let's say a male who's undergoing a hormone replacement therapy with exogenous testosterone, what we know is with certain forms of testosterone replacement therapy, after some period of time, the testes will stop producing their
own testosterone. And even if you were to stop your exogenous injection of testosterone, your production of testosterone innately never returns. And the worry is is that the case with melatonin. Now, there have been a number of case studies that have looked at melatonin use, let's say, for up to four or even six weeks of constant use, and when they stop, melatonin production returns. So it looks as though we don't
have to worry. My worry though, with those data, when someone has sort of offered them to me, is to say, but most people in society, they're not using melatonin like that. They've been using it for years, not six weeks. So I think I'm still a little bit sort of concerned. The other thing, or two other things. One is that the dose that people typically take is what we call a super physiological dose, meaning it's far higher than anything
your body would naturally release. So people are taking five milligrams, ten millograms, maybe sometimes even twenty milligrams, whereas what we would recommend in sleep medicine is somewhere around about one maybe maximum of three milligrams. So you know, log orders of magnitude higher. The other thing too to keep in mind is that melatonin now is being more and more used in the pediatric setting, so you'll see these melatonin
gummies for kids. And there was some data of gosh now probably thirty years ago, looking at juvenile mail rats, meaning that they're going through that sort of adolescent phase, and they were getting dosed with high amounts of melatonin, and that high dose of melatonin in the juvenile male rats actually stunted their sexual development. So it's stunted testicular growth, and it caused testicular atrophy, meaning shrinking of the testes.
Imagine if I were to go to let's say a teacher and parent meeting one evening at a school and get up there and say, I would like you this evening to start dosing your children with a bioactive hormone. And it is a hormone that I would like you to dose your children with every night at maybe five to ten times their natural release. And also it's a hormone that may actually disrupt their sexual maturation and development. Who's with me, you know? And at that point, people
would you know, boo you off the safe rightly? So now again, I'm being a hyperbolic and we don't know if there is that concern or not. I'm simply saying that if we don't know, my sort of suspicion, at least personally would be I'd probably err on the side of caution at least stage, particularly because the FDA recently released data demonstrating that admissions to hospitals for melatonin overdose have increased by five hundred and three percent in the
past ten years. So there is something going on with melatonin. I think that we need to be mindful of. Again, though it's largely an inert compound, so I don't need to be scam mongering here. Your second part of the question was sleeping pills. Yeah, and it's a really interesting evolution. I think we're now at the stage of sleeping pills three point zero. We sort of web one point h two point zero three point zero. It's kind of the
same with sleeping pills. We started off with the classic benzodiazepines, things like valium, and they work to go after an inhibitary chemical in the brain, neurotransmitter in the brain called GABBA, which stands for gamma amino butyic acid. Don't worry about the name. It's simply the red light stop sign for brain activity. These things like valuum. They would go after this Gabba system in the brain and they would activate
it and essentially just knock out your cortex. And then the second generation of sleeping pills came along, the ambient Lanesta sonatas of this world. They also go after that Gabba inhibitry and neurotransmitter system in the brain, but they just sort of tickle the receptor in the brain a little bit differently, but for the most part they are doing the same thing. And that's why we call them
the sedative hypnotics, because they are sedating your cortex. Now, if you take an ambient at full dose, I'm not going to argue that you're awake, you're clearly not awake, but to argue that you're in naturalistic sleep. In some ways, it's an equal fallacy, because if I show you the electrical signature of your sleep with and without ambient, they're
not the same. And in some ways, ambient will come in and it will take a bite out of the deepest of the deep slow waves of deep non rem sleep, sort of this big dent that you see that happens, and so again it's not necessarily to say that there isn't a time and a place for the use of those medications. Sleep medicine right now does recognize them as being useful potentially in the short term to start to begin treatment for insomnia, but they are no longer the
first line recommended treatment. And one of the reasons that in a book that I wrote where I was sort of I probably wasn't overly enthusiastic about those WEB two point zero sleeping pills the ambience less and snartists, and it was for several reasons. First, because sedation is not sleep, and when you take those medications you mistake the former for the latter, but it's not natural sleep. We also know that those sleeping pills have been associated with higher
risks of mortality in certain forms of cancer. Now those are associations, we don't know necessarily that that's causal. But then there was another very interesting study where they looked at how sleep helps your learning in your memory. And one of the incredible things about sleep is that it will take recently learned memories and that memory circuit in the brain. Sleep will strengthen the synapses so that you come back the next day, and that memory is almost
like hitting the save button on those memories. Wow, you cement it into the architecture of the brain. And they did a study where they dosed animals after learning amaze or different types of learning, and they could measure the strength of the memory circuit, and then they gave them natural sleep, and sure enough, the next day sleep it almost double the strength of the memory. Then they did a version where they dosed the animals with a body
appropriate amount of ambient and those animals slept longer. And you would think, well, if sleep is helping the memories and strengthening that memory circuit, sleeping longer should lead to an even greater strengthening of the memory. Unfortunately, ambient had unwired them memory and it actually reduced the strength of
the memory by fifty five zero. So to me, that's just a demonstration that perhaps the quality of sleep is not a naturalistic quality of sleep, and it may not therefore be transacting the natural functions that sleep typically provides light learning and memory. There is a newer class of medications, though, are out on the market, and I think the evidence right now is still early, but so far, I actually
think that they look really quite effective. And again I think people had taken my stance to be I'm very anti pharmacology in general. I'm not. I'm very pro pharmacology if the pharmacology is good and not necessarily causing you harm. And these new class of medications they are called the Dora's Drugs and it's do r A small s and it's a class of drugs and there are currently three FDA approved. The first one was called bell Somra and to play on sort of beautiful sleep, and the actual
chemical name is suborexin. These medications do something really much more elegant the ambience and the lenestsis said, that's just a sedative hit to the cortex. These new class of medications the doors they go after awake promoting chemical called erexin. You can think of a rexin like the wakefulness volume
button and when it's turned up, we're wide awake. And these medications they come in and they act like an additional set of chemical fingers and they just go after the volume button of wakefulness of a rexin and they just dial it down and then they step back and they allow the antithesis of wakefulness to come in its place, which is this thing called naturalistic sleep. And so I
think right now I'm probably more bullish on those medications. Again, a lot of water to pass under the bridge before we understand them, but so far I think that there are much more elegant, nuanced way of manipulating sleep. The other thing I would be remiss to mention is there is an alternative to these medications in general, and it's called cognitive behavioral therapy for insomnia or CBTI for short. It is just as effective as sleeping pills in the
short term. But what's nice is that when you stop working with your therapist after maybe six or eight sessions, not only do you with a sleeping pill like ambium. When you stop, you typically go back to the bad sleep that you are having, or you actually have rebound insomnia where your sleep is even worse. But with a therapist, they're giving you the tools and techniques. It's sort of the difference between let's say, you know, giving a woman or a man of fish versus teaching them how to fish.
This way, you actually understand how to manipulate your sleep. They give you the tools and then you can continue to sleep better for years later, even after you've stopped utilizing the therapy unlike medications. So I would just say that that's a little bit about both melotonin, the sort of the emergence of these new flavors of sleep medications, and then an alternative should people wish for that.
Yeah, it's it's so worrying because I think we've got so used to treating our brain and our mind like technology, and this desire to just switch it on and off. Power our power down, power on, power off. It's almost like you don't ever really stop to think what's happening in order for that to happen. And I know I didn't for a long time where I grew up and you just pop a more paracetamoor from where we're from, but I go from you know, in the US, and
you've got a headache, Just take this, it's gone. You know, you can't sleep. Take this. You fall asleep, and you're not really recognizing what's happening at a chemical level and how many consequences there are and what's what's actually happening
beneath the scenes. And I think it's so easy to forget because it's giving you the instant thing that you want in that moment, but the kind of circuitry that it's kicking off or closing down as far more long term consequences that, like you said, we're not even aware of. It's sad and hard and difficult that wanting to get these natural things to happen that we are naturally wired
to do. Right. These chemicals are being naturally produced, and there are natural things we can do to boost those chemicals within ourselves that hopefully get us to go to sleep, as you talked about, like seeing light first thing in the morning, like you know, being outdoor more, reducing blue light in the evening, reducing exposure to junk light as you called it, in the evening. I've definitely seen that one make a big difference. I'm someone who generally loves light.
I really like being in bright places, and my wife's the opposite. She knows she's very much like wants to follow the sun, and so when it's dark, she'll be like, all the lights have to be off in the house.
And recently when we've been watching our shows, we've been watching our shows in total darkness apart from the screen obviously, and it's so natural for both of us to just feel tired earlier, Yeah, and we'll be like, all right, time to go to bed, and we don't have our screen in our bedroom, and so we'll finish watching whatever we're watching, and we've sometimes we're both even like you can tell we're just falling asleep while watching. We figure it out, turn it off and go to our bed
and we're out to sleep. And just simply completely making it dark in the evening has had a huge, huge impact.
On Honestly, I love that you bring this up. And I would say to anyone listening, if you're going to do anything with this podcast in terms of an actionable event, just do this one thing for the next week. If you get the opportunity, just do me this favor. Set it to bed alarm one hour before you would normally go to bed, and when that alarm goes off, shut down fifty percent, if not seventy five percent of all
of the lights in your home. And then see how soperific that will make you feel, how sleepy that you will make you feel. It's really quite striking. Then don't just stop there. Do what I would call the off on off version of the experiment. So baseline, you're coming in, you're normally leaving the lights on blazing. Now we go into the on version of the experiment, the intervention, which is darkness one hour before bed, and then after that one week, go back to doing what you used to do.
Keep all of the lights blazing for right up until you go to bed. And don't just ask the question did my sleep get any better when I did the manipulation of one hour before bed switched the lights off? Ask the question did my sleep go back to being actually worse when I returned to keeping the lights on? And so you show by directionality, And when you show by directionality, it's usually a much more powerful version of
the experiment. But and if honestly you can say to me it made no difference to my sensation of feeling drowsy and sleepy or the quality of my sleep, then no problem at all. Keep doing what you're doing and it just didn't work for you, that's fine too.
But first, here's a quick word from the brands that support the show. All right, thank you to our sponsors. Now let's dive back in. I love what the advice you give for people who are struggling with insomnia, For someone who's waking up they go to sleep for three hours, but then they're up. They finally put themselves back to sleep after an hour and a half and they sleep for maybe another three hours, and then they're back up again.
For that person, what's the most helpful way for them to be able to fall back asleep in that moment. So we've talked about the roots of the issues and the core from the acronym, but what about that person is just like, I just want to know how to get back to sleep for another three four hours if I could, Yeah, what's the quickest way I can do that?
I would say there are three things to keep in mind here. When I often hear that description, people will say I always wake up, but it's about three point fifteen in the morning or it's four ten, and it just happens so reliably. My first question to them is, how do you know it's four o'clock in the morning. That's your problem. You're looking at the clock and knowing that it's three point fifteen or four am in the morning. Does you no favors at all? It's not going to
change the outcome. So the first recommendation is remove all clock faces from the bedroom. It's okay to if you really must do. Keep your phone next to your bed, but keep it out of sight, even though I would strongly recommend that you keep your phone in the kitchen, or even better still, a friend of mine recommended recently just put it in the garage. Put it in your
car in the garage, and that way. The amount of motivation effort to go and get your phone within the first ten minutes of the morning is very very high, meaning you're probably not going to do it. So let's baby steps. Let's just say crawl, walk, run. First thing to do. Just make sure you can't see any clock faces, and if you wake up, resist the urge. Because as soon as you start doing that night after night, you're actually training your brain, reinforcing it to wake up at
three pin fifteen in the morning. So we've started that. The next question is, well, what should you do about it? You know, don't tell me the fancy, remove the clock, help me at that point at night, either if you've woken up or you just can't fall asleep. It works for both of these. The problem here is that you have to get your mind off itself because at that moment when you're awake, you start thinking, okay, I'm awake. This is now going to just obliterate my day. Tomorrow
I've got that important meeting. I'm now going to be underslept. At that point, the anxiety starts to begin. Then you start thinking, oh gosh, I remember now I didn't do that one thing that I should have done for tomorrow morning, and then I've got to do that thing for next week, and I also didn't do that thing last week for and again at that point, that's going to keep you awake for the next one or two hours. So your job to try to get back asleep is to disengage
the mind. How do you do that? I would say there probably four or five different tools that you can use. Is meditation. It may be or may not be for you, but if you look at the data, meditation for sleep immensely powerful. If meditation is not your thing, just do something simple like breath work and you can just google box breathing and anything like that is great. You could
also just do a simple body scan. Start at the top of the head, move down just and again google body scan and you can start to train yourself to do that. The next thing you could do is listen to a sleep story or just listen to a podcast, make sure it's on a timed sort of shut off. But again, all of these things common across all of them is you're getting your mind off itself. If I'm meditating, I'm not thinking about my worries. If I'm breathing, I'm
focusing on the breath. If I'm doing some kind of a relaxation, a body scan, again, I'm just moving through my body. It's very hard for me to think about my anxieties. If I'm listening to a sleep story, I'm engaging in sort of the externality of the story, not my own in internal worries. And then the final thing that was done is great study done at you see Berkeley, not by my group. They found that taking yourself on
a mental walk in hyper detail was wonderful. So let's say it's a walk that I take with my dog, and you've got to remember it in high detail. So I think, okay, I open the drawer, which colored leish am I going to take? I'll take the blue one, clip it in with my right hand. With my left hand, I open the door, take a left down the stairs, go up. It's at that level of detail, and all of these things are taking your mind off itself because at that time of night, sleep is a little bit
like trying to remember someone's name. Sleep is not something that you make happen. Sleep is something that happens to you, And like trying to remember someone's name, the harder you try, the further you push it away, and it's only when you stop trying does it return to you absolutely, and that's the same way with sleeping. Normally, if you engage in some of these methods and tools, the next thing that you remember is your alarm going off in the morning. Why,
because you took your mind off itself. If that doesn't work and you are consistently waking up and spending long amounts of time in bed awake, then we may have to implement one of the methods in cognitive behavioral therapy for insomnia, which is something called bed time restructuring. It used to be called sleep restriction therapy, and for reasons, obviously you can think it's not the best name. Where you come to me and say, look, I'm having real
problems getting enough sleep. My say, great, we're going to do sleep restriction therapy and you say no, no, wait, wait a second, you didn't hear me, I can't get enough sleep, and you're saying you're going to restrict my sleep. It's actually not sleep restriction, it's time in bed restriction. So you tell me, Okay, i am in bed for eight hours and I'm awake for two hours across the night, so I'm only getting six hours of sleep, but I'm
in bed for eight hours. To me, as a sleep scientist, I then know we've got to constrain the time with which you are giving your brain the opportunity to sleep, because your brain has become inefficient. It's like saying, I go to the gym and I take an hour to work out, but if you are to actually observe me, I'm actually only working out for about twenty five minutes because you know, at the end, I finish my you know,
my last strip. Then I do the eleventh rep, which is I pick up my phone and I start checking social media, and then I'm talking to people. Utterly inefficient. But then at some point someone says to me, look, today, you've only got a maximum of thirty minutes in the gym, and as soon as your thirteen minutes is up, we kick you out. The first couple of days I'm still doing what I normally do, and I get through maybe fifteen percent of my workout because I'm not doing it efficiently.
After a week of doing that, I now realize as soon as I go into the gym, I put my phone down and I just go at it real hard, and I still get my twenty five minutes of workout in the thirty minutes. It's the same with sleep restriction. You tell me, Okay, I'm in bed for eight hours and I only get about sort of six hours of sleep. Well, now I'm going to say I'm going to limit you, and I'm going to take one hour of sleep away
from you. You wake up at the same time, but I want you to go to bed consistently one hour later, maybe even one and a half hours later. You tell me I go to bed normally at ten pm. I say you are now not allowed to get into bed until eleven thirty pm. Push through. I don't care. And then you've got to wake up at the same time. And after about three or four days of this, your brain starts to build up. Now, the first couple of nights, you're still going to be sleeping bad. But then after
a couple of nights. Your brain starts to build up this starvation, this hunger for sleep. It creates a sleep dead and then after a while, it's like resetting the Wi Fi button on your router. The brain thinks, gosh, I don't have the luxury of eight and a half hours of time in bed. I'm only allowed six and a half now or seven. And now, all of a sudden, it becomes incredibly efficient. You stop waking up in the
middle of the night. If you do wake up, you fall back asleep very quickly, and you end up getting maybe six and three quarter hours of sleep within seven whereas you used to get six and a half hours of sleep with eight and a half hours of time in bed. So it's a quite convoluted method, but I would say I would use that as the last approach. Firstly, try to get your mind off itself. If it's still not working, think about sleep restriction therapy. You can just google it. It's pretty simple.
Great advice. Thank you so much. I love how tactical and practical you are. Oh, it's so helpful. Like if there's anyone who's listening to this episode right now, and you have a friend or a family member who's struggling with sleep. Please pass this episode on because I've never
heard someone make it that granular as you are. Honestly, it's so brilliant and it's so helpful because it's so easy to get philosophical about these ideas, and we all understand how important sleep is and how much we need it. And you know, I can hear everyone going, yeah, but what do I do? Really, You've created a map for people, So thank you so.
Much for you. Well, I think I really it was very guilty of doing this. You know, when I first came out a couple of years ago speaking about sleep, I was speaking all about the science of sleep and the bad things that happened about sleep. And I think someone even said my ted talk, which I think was called they name it sleeps your Superpowers, I mean, should have really been called sleep or else dot dot dot, you know, and it did people with insomnia no favors.
I understand that now. But I think what I've tried to do is people have said, Okay, I get it, sleep is important, but how how do I get it? And I completely suffered what we call in neurology is HEMI neglect one half of what I needed to do as a sort of a public intellectual regarding sleep was missing, which is I was telling everyone how critical it was and the bad things that happen when you don't get it.
But I wasn't being very helpful because I wasn't telling anyone how it works and how you know, where is the user manual for sleep? And that's what I'm now trying to do. So thank you for saying trying to do a little bit better. You really had to do less bad.
Let's just say, yeah, now it's coming across great. I want to move on to talk about caffeine and coffee. You spoke earlier. You said we should be having our last cup of coffee or caffeine at ten to twelve hours before we go to bed. Yeah, And when I was listening to that, I was like, I think a lot of people are not doing that, Like from what at least from the conversations I'm having, I think people are having it much closer to bed, or they're having
so much that it's affecting their bed. If you had to tell people just a couple of things about caffeine or coffee and sleep, what would you want them to know?
I think I would say that. Firstly, caffeine has a half life for the average adult of five to six hours, which means that after about five to six hours, fifty percent of the caffeine is still circulating in your brain. That means that caffeine has a quarter life of ten to twelve hours. So if you have a cup of coffee at noon, twenty five percent of that a quarter of that cup of coffee is still in your brain
at midnight. So I don't think many of us would get into bed and sort of pour a quarter of a cup of coffee and then twig it and then you know, put your head on the pillow. We understand that that probably doesn't need to good sleep, but in some ways that's not dissimilar to what you're doing if you have a cup of coffee at noon. Keep in mind, however, there is variability that some people have a faster capability to metabolize or at least clear caffeine from the system.
And you can do these genetic tests, and there's an enzyme called the CYP one a two gene, and that will dictate the speed of it as sort of a liver enzyme, a cytochrome enzyme that will speed or slow down, and you will know if you're caffeine sensitive or not. So firstly, the timing of caffeine can be important. Also the dose, and that's why we've looked at people. Even if you just have one weekly sort of drip brewed cup of coffee in the evening, I'd say it's just
one hundred milligrams of caffeine. It will not necessarily prevent you from falling asleep as efficiently, but it will increase the chances with which you wake up, and if you wake up, it will increase the duration with which it takes you to fall back asleep. And if it doesn't do that, it can also reduce down the depth of
your deep sleep. And we know, for example, that it's during that deep sleep when your brain has a cleansing system that washes away things like the Alzheimer's proteins, amyloid and tau protein. So you really would prefer not to try to degrade the quality of your deep sleep, considering all that it does for your brain and your body. But in some ways that's what many of us are inadvertently doing if we have caffeine too late in the day. I would say, though that I've probably changed my tune
a little bit on coffee. I would say, drink coffee, but the dose and the timing make the poison. Try to, as I said, cut yourself off after about three cups of coffee, and try to cut yourself off at least ten hours, you know, as a rule of thumb before bed. The reason I reverted back in some ways to say coffee is not necessarily a bad thing to drink. If you look at the relationship between drinking coffee and the health benefits, they are non negotiably astronomically impressive. Drinking coffee
seems to be a very good thing. Now again, it's dose dependent. Once you get past about four cups of coffee, then it goes in the opposite direction. It's not a good thing. And if you look at that list, and it is quite a list of health benefits and disease de risking that drinking coffee provides, and you compare that to all of the health benefits that sleep provides, it's a remarkable overlap. So people were saying to me, how
do you square that circle, because that doesn't make any sense. Well, if you look at the data, the reason that drinking coffee is beneficial is because the coffee bean itself contains a whopping dose of antioxidants, and because in the Western world we're so deficient in our dietary intake of antioxidants, this one thing, the coffee bean, has been asked to carry the herculean weight of all of our antioxidant needs. And therefore that's why drinking coffee has such a health
predictive signal in the literature. Case in point, if you look at decaffeinated coffee has almost the same health benefits. So it's not the caffeine, it's the antioxidants in the coffee bean itself. So again, with all of these things with alcohol and caffeine, I am just a scientist. I have no right to tell anyone how to live their life, and I don't want to be the healthiest person in the graveyard either. Life is to be lived for good you know, jouir de vive for goodness sake, live a
little bit. All I simply want to do is in empower you with the scientific evidence and then you can make an informed choice as to how you want to live your life. But does that help a little bit in terms of navigating caffeine?
And yeah, absolutely huge and The other thing you mentioned at this point of the the acronym is alcohol, and you were talking about how just the negative effects of alcohol in terms of that disruption of our sleep. If there were a couple of things you wanted people to know about alcohol and sleep, what would they be.
Yeah, there, I think I probably haven't changed my tune and I don't see any upside in terms of alcohol for health or certainly for sleep. Alcohol is probably the most misunderstood sleep aid that there is out there. Unfortunately, it's not an aid at all. Alcohol will hurt your sleep in at least one of three different ways. The first thing is that alcohol is also in the class of drugs that we call the sedatives. And again, when you have a couple of sort of nightcaps in the evening,
you say it helps me fall asleep. Alcohol is simply helping you lose consciousness more quickly. It's not really putting you into natural sleep. The second thing is that alcohol will fragment your sleep in the first half of the night. And the reason that it does that is that alcohol
will activate the fight or flight branch of the nervous system. Now, in the first half of the night, that's when we get most of our deep sleep, and when we go into deep sleep, we shift from the fight or flight branch of the nervous system over to what we call
the parasympathetic nervous system, which is this quiescent nervous branch. Now, alcohol will crank you back over to the fight or flight sympathetic nervous system, which then makes your sleep, the depth of your sleep far more shallow, so you don't
get as much deep sleep. You wake up more frequently, But those awakenings are so brief that you never commit them to memory, so you never think alcohol is harming my sleep by fragmenting it, sort of littering it with all of these awakenings, so your deep sleep suffers, your sleep is fragmented. Then, finally, alcohol is very potent at blocking your dream sleep or your rapid eye movement. Sleep and dream sleep is critical for things like emotional and
mental health. It's essential for creativity. It's also important for hormonal health. It's during rem sleep when we release our peak levels of testosterone in both men and women, and alcohol will sort of short change you of that rem sleep. So on all of those counts, you know, I just can't say in good conscience. Even a glass of wine with dinner, you know, is that okay, we can see
the blest radius. It is in some ways both a dose and also time dependent process, such that if you have, let's say, a glass of wine with lunch versus a glass of wine with dinner, the glass of wine with lunch will have less of a damaging impact on your sleep at night. So the completely politically incorrect thing that I would never say on a podcast would be go to the pub in the morning and the alcohol is out your system in the evening and no harm, no foult.
But no, of course I would never suggest something like that. But yeah, what are you doing tomorrow morning?
Now, before we dive into the next moment, let's hear from our sponsors and back to our episode. Like you said, I think it's so easy for human just ideas that become prevalent in human society that we just take as being normal, or habits and practices that become normalized over a certain period of time, and we just start operating like it's normal, it's okay, it's accepted, and not really
realizing what's going on. And I'm also of the spirit of we should enjoy life and appreciate life and everything else.
But I think to really appreciate life, it means to know what works for you and what doesn't, and what helps you and what doesn't, Yeah, and to really recognize the value of the impact of that, because I think it's really easy to be like, oh, yeah, well, you know, let's just see how things go, and then all of a sudden you hear about a family member or a friend who gets a diagnosis, and then that's when it
kind of really hits you. And I've had that far too often, where I've had friends and family members at young ages diagnosed with things and it's consistent with a habit. And by the way, sometimes someone gets something and it's got nothing to do with their habits and it's bad luck and it's you know, everything else. And both of those are positions to be compassionate and empathetic. But I think when it comes to ourselves, I look at it and go, I would like it to not be my
own fault. If it happens from something beyond me, great, Yeah, But if I can avoid it by taking responsibility and accountability for my health, then that's probably a good play and a good way to live. Yeah.
I like the way that you're thinking. They're in the sense that so many of us see sleep as a cost to our lives. Yes, and instead, I think what we have to realize is think of sleep like an investment in tomorrow, not a cost of what I get for today. And you're right when you look at some of the mentality of you know, I'll sleep when I'm dead. I mean, firstly, what we know from the data is that if we adopt that mentality, you will be both dead sooner and the quality of your life will be
significantly worse as a consequence. But also if you look at the data between short sleep and cardiovascular disease, if you look at short sleep and certain forms of cancer, not all forms of cancer, short sleep and dementia risk.
Imagine if you were to say, in twenty years time, when you're at the hospital and you've just lost a third of your heart function because you've had a massive cronary blockage, if I were to at that point say I could wave a magic wand right now in the hospital at your bedside, and if only you could go back twenty years and start investing in your instead of maybe adopting what some not all people, but some have this sort of almost this it's almost like a sleep
machismo attitude. I think in certain sectors of the workplace we've got this competitive undersleeping, you know, mentality, the sleep braggadoccio notion. But I know no one who twenty years later in a hospital wouldn't say, if I could go back and remove all of this cardiovascular consequence that you've just had by way of this heart attack, if only you'd gone back and started just to try to invest even just five or six days a week in consistent
good sleep, would you do it? Most people at that point would say absolutely, I wish I could take it back. But it's so hard for us to prospect into the future and do back casting. Many of us just can't do forecasting at all very well in terms of our health. So what do we do? We burn the candle at
both ends. Also, I think it's not anyone's fault regarding this global sleep loss epidemic, and this it is a consistent sort of sleep neglect, because firstly, I think society is conspiring against us to get sufficient sleep, because sleep has this image problem. We think of people who get sufficient sleep as slothful, as lazy, that sleep. Whoever the pr agent for sleep has been, we probably should have fired them long ago, because I'm going to try and
bush back at least. But also from a perspective of someone who doesn't know anything about sleep, I would just think, well, my body's at rest, my mind is dormant. How much danger is there really in losing one hour of sleep or even two hours of sleep? Surely there's not much danger. It can even actually change your very nucleic alphabet. So I'll tell you about a fascinating study that impressed upon
me the importance. They took perfectly healthy individuals and they limited them to six hours of sleeper night for one week. By the way, six hours of sleep a night for one week is actually what many people are getting in society. At least a third of the population seemed to be getting six hours or less during the week. So it
was a very sort of ecologically relevant experiment. And then they measured the change in their gene activity profile relative to when those same individuals were getting a full eight hour night of sleep, and there were two key findings. First, a sizeable and significant seven hundred and eleven genes were distorted in their activity, caused by that six hours a night of sleep. If that wasn't impressible enough, the second was that about half of those genes were increased in
their activity, the other half were decreased. Now, the genes that were increased in their activity were genes that were associated with biological stress and cardiovascular disease, genes that were associated with the promotion of tumors, and genes that were associated with long term chronic inflammation within the body, whereas though genes that were actually switched off or turned down
were genes associated with your immune system. And so to me, what that demonstrated was that there's no aspect of our wellness that can retreat at the sign of sleep deprivation and get away unscathed. That it's almost like a broken water pipe in your home. That sleep loss will leak down into every knock and cranny of your physiology and even tamper with the very DNA alphabet that spells out
your daily health narrative. And so why if you didn't know that evidence, why would you think that sleep is so necessarily important. If I, just as a late public person, would be thinking, well, my mind's dorm up, my body gets a bit of a rest. Well. I can rest when I'm watching Netflix. My body gets plenty enough for rest there, so I don't need my sleep. But if you think about it, sleep is the most idiotic of
all evolutionary creations. You know, finding a mate, You're not reproducing, you're not caring for you're young, you're not foraging for food, and worse, you're vulnerable to predation. Sleep should have been strongly selected against during the course of evolution if it wasn't important. It is absolutely important. It serves a constellation of different vital functions for brain and body. But if I didn't know about them, of course I'd neglect my sleep.
So I'm simply saying that to both impress the importance of sleep, but also try to be compassionately sensitive to why. I understand people neglected not because they're trying to show how brave and teflong coated they are. It's just because no one understands sleep. So that's why I've tried to sort of make it in part A mission for life
is sleep has been than the neglected stepsister. In the health conversation of today, we speak a lot about diet and exercise, and that's great, and because of people like you. I think we're speaking so much more about emotional and mental health, which to me is the fourth pillar of life and health. Sleep is one of those pillars too, though, and so hope this helps a little bit.
No, it's brilliant, Matt. I think you are the best pr agent be Sep could ever ask for. I think your method of communication, the empathy and compassion that comes with it, the lack of judgment, and at the same time waking us up to the reality, which I think is an important part of the narrative, comes across extremely clearly. And I'm so grateful, and I hope you'll come back on many many times. I had to depose this question to extend it. There's so much we didn't even get
to today. But we end every on Purpose episode with a final five and these have to be answered in one word or one sentence maximum. But I know I'm going to break that rule with you already. So the first question is what is the best sleep advice you've ever heard, received or given regularity?
Digital detox, going to bed at the same time, waking up at the same time. Do that so many other things like quantitine quality will fall into place, and then the second is as much as you can in the last hour before bed, try to stay off your phone and in the morning give yourself ten minutes. Why because what we do is we train ourselves. What's the first thing that most people do when they wake up, They open their phone, and there's this way the tsunami of
anxiety comes flooding in every day. You are training yourself when you go to bed at night to expect that huge wave of anxiety when you wake up. It's what we call anticipatory anxiety. And most people will have had this. You have an early morning flight and you know you've got to wake up for it. It's essential. And you also know that your sleep that night will be so shallow and so sort of diminutive.
Early.
Well, this is a diet version of that. But every single day, by way of swiping open on your phone next to you, just give yourself ten minutes in the morning. I promise your sleep will be better. So regularity digital detos.
I love it. What's the worst sleep advice you've ever heard received or given?
That you can make up sleep at the weekend. You can't accumulate a debt and then hope to fully pay it. Off at the weekend, and there's some great evidence looking at all sorts of brain and body metrics that for the most part, some of them you can kind of
sleep back at the weekend. But for the most part, when you look at your cardiovascular system, your metabolic system, your immune system, your hormonal system, if you look at your brain processes, your cognition, your emotional stability or instability, all of these things do not fully recover by weight of weekend sleep. So you can't do this binge purge process. So I would say that the myth of makeup sleep is unfortunately just that that it's not like the bank.
Yeah, so you just have to get into a good rhythm and a good pattern and invest in it.
It's just I mean, if it was like that, trust me, you know, mother nature would have figured out a way to have us short sleeping all the time, because it's sleep is so deleterious to any organism, and if there was a way to short change, we would have been short changing long ago, and it would be baked into
our sort of sleep DNA biology. The fact that it's not that human beings are the only species that will deliberately deprive themselves of sleep for no apparent good reason is testament to the fact that you just can't make it up like that, the system doesn't work like that.
Question number three, how does what does bad sleep do to your mental health?
Firstly, you become much more emotionally erratic. You become pendulum like, why is that? Yeah, part of the reason is because there is a part of your prefrontal cortex right down in the middle. So my prefrontal cortex sits right above my eyes. It's the most evolved part of our sort of hominid brain. It's what makes us human beings. That middle part of the brain acts like almost a brake pedal on our emotional accelerator regions deep in the brain.
And when we are underslept, that part of the brain gets shut down. So now we become all emotional gas pedal and too little regulatory control break as it were, and that's why we become so reactive. We become you know, it's that I just snapped dot dot dot fill in the blank when I am underslept. So firstly, our regulation of our emotions becomes impaired as a consequence. Secondly, the anxiety centers of the brain can become thirty to forty
percent more reactive when we're not getting sufficient sleep. You can flip that narrative then and say, well, if that's the bad that happens when I take sleep away, what is it about sleep when I do get it that is beneficial? And what we've discovered is that it's rem sleep or dream sleep that provides a form of almost
overnight therapy. Dream sleep is emotional first aid, and it's during dream sleep that your brain takes those painful, difficult experiences and acts almost like a nocturnal soothing bomb, and it just takes the sharp edges off those painful, difficult experiences so that we come back the next day and we feel better about them. It's that idea of it's not time that heals all wounds, it's time during sleep, and specifically dream sleep, that provides emotional convalescence. And there's
a wonderful gosh. I wish i'd come up with this quote by an American entrepreneur, E. Joseph Cosman, and he once said that the best bridge between despur and hope is a good night of sleep. That's exactly what dream sleep provides.
If you love your family, the best thing you can do is get a good night's sleep.
When you have had a good night of sleep, I think we all sense this. You wake up and you are dressed in a different set of psychological clothes. It's almost as though sleep provides this sort of emotional winds, green wipeer benefit and we can see clearly and to me, that's I think one of the most powerful aspects. Sleep gives me back the rose in the tint of my worldview glasses every single morning.
I mean, I experienced that all the time. I know what I can be like if I haven't had a good night.
Yeah. Yeah, I'll sometimes say that to my much better half, you know, when I come up, I'll say to her, look, you know, darling, I am I'm so sorry I didn't sleep well last night. I am not the best version of myself. For whatever I do today, whatever idiocy that I you know, enunciate or behaving, ye, please forgive me and I will make sure that I will do all the dishes for the next two months.
Yeah. Sleep effects our emotional relationships, intimacy, everything, question number four, I have something in my mind. I was gonna ask you, what have you seen as being a surprising connection that's connected to sleep, something that sleep impacts that surprise you do something a bit that we might not have heard of.
We've done some cities looking at what I would think of as more complex pro social behavior, and what we found is that a lack of sleep will immediately make someone become more asocial, meaning that they withdraw socially. They do not wish to have the contact with other people
that they typically do. They become therefore more isolated. They feel more lonely as a consequence, and we know that there is this epidemic of loneliness happening, we didn't realize how much a lack of sleep was contributing to that.
Worse still, when you interact with someone who is sleep deprived and you are well rested having had that interaction with the sleep deprived person, when we ask that person, do you feel any more or less lonely in this moment, they rate themselves as now feeling more lonely themselves having interacted with a sleep deprived individual. In other words, the loneliness that a lack of sleep creates is contagious and
it is transmitted from one person to the next. The second thing that we looked at was perhaps one of the most fundamental components of US Homo sapiens, which is that we help each other. It's what we call pro social behavior. And I cannot imagine any modern civilization that has emerged without pro social helping between individuals. It's a fundamental ingredient. We help each other. And what we found is that when you are underslept, you withdraw your natural
tendency to help other human beings. We observed it at the level of me helping other people, we observed it at the level of entire groups helping each other. And we also found it across entire nations. And you think how you figure that one out. There is a global experiment that's performed on one point six billion people across seventy countries twice a year, and it's called daylight Saving Time.
And what we did we looked at the National donation database across the United States, which is in some ways a measure of selfless giving. I give to charity, I give to other people. And what we found is that in the days after the spring daylight savings time, when we lose one hour of sleep, there was this huge dent in proactive giving by way of donations to charities,
we become more stingy, we've become more self centered. So I would say that it's this new wave of sleep science that goes beyond the DNA nucleus that we spoke about. It goes beyond cells, it goes beyond physiological systems, It goes beyond entire brain networks, It goes beyond the organism themselves. It now translates to a lack of sleep impacting our inter relationships and impacting the very fabric of society itself. That to me has been stunning and quite surprised.
Yeah, that is a surprise. I was not expecting that. Yeah. Fifth and final question we asked this to every guest who's ever been on the show. Matt if you could create one law that everyone in the world had to follow, what would.
It be self forgiveness?
Why?
Because I think that there is so much ill grace that is enacted by ourselves on others, because we are not good with ourselves, that it makes me sad at
some times. And I think so much of what we react to others is really about a mirror being held up to ourselves and the pain of that that if we just let go and gave ourselves, self compassion and self forgiveness, society would be I think demonstratably, which is to say, demonstrably better as a result in truth, though that's probably me just holding a mirror up to myself to your.
Question, peerful Matt, thank you so much for your incredible work, incredible sharing of insights today, and I really hope you will come back for another episode because I have another million questions to answer. Thank you so much. I'm so
grateful for your time and energy. I hope everyone has been listening and watching back at home, at work, whether you're on a hike, whether you're with your dog, whether you're on driving right now, wherever you are, I hope that you will find it possible to try some just one, even if you just try one of Matt's suggestions today. I really truly believe your life will change, and as Matt said, it will impact all other areas of our lives.
Please prioritize your sleep and watch how your life changes.
Thank you so much, Matt, Thank you, and can I just say thank you to you for what you do for society. You have dedicated you yourself to the wellness and the health of the rest of humanity. But what I see as a big differentiator is that you have a very genuine passion for doing this. You mean it when you say it, thank you, And I think that's why, in part you've had just this incredible impact on society.
Authenticity is a very rare thing, and as human beings, were actually very good at identifying it and also identifying its absence. And one of the reasons that I just have such admiration for what you do is not just that what you're doing is an incredible service, but the authentic way that you're doing it, because you genuinely mean it, is something that I think is a remarkable beauty to behold. So for all that you do for society, thank you so much.
Well, thank you, Matt. That's extremely gracious and kind, genuinely that touch my heart. Thank you so much.
Thank you.
If you love this episode, you'll enjoy my interview with doctor Daniel Ahman on how to change your life by changing your brain.
If we want a healthy mind, it actually starts with a healthy brain.
You know.
I've had the blessing or the curse to scan over a thousand convicted felons and over one hundred murderers and their brains are very damaged.