SLEEP EXPERT Reveals How To Optimize Your Sleep To LIVE LONGER! ¦ Matt Walker

Right now, the recommendation is for most adults, get seven to nine hours of sleep. And to get, by the way, to get seven hours of sleep, you probably need at least a seven and a half hour sleep opportunity. I think that's what many people miss in recommendations from sort of experts. They say, get your seven hours of sleep. So people think that means, you know, well, if I go to bed at 11 p.m. and I wake up at 6 a.m., then I've got my seven hours of sleep. That's not true. You probably will have only logged about sort of six hours and 40 minutes and that's not enough. So you need to think about the sleep opportunity time as being probably around about eight hours optimally. What we also know is that once you get below seven, we can start to measure objective impairments in your body and in your brain as well. The problem is that most people don't realize that they're sleep deprived when they're sleep deprived. This is a big problem with sleep loss. And, you know, the analogy, I guess, would be a drunk driver at a bar. You know, they've had a couple of pints, maybe a few shots, and they pick up their car keys and they say to you, you know, look, I'm fine to drive home. And you say, no, I know that you think you're fine to drive home, but trust me, you're not. You are objectively, you're impaired. It's the same way with a lack of sleep that our subjective sense is a miserable predictor of objectively how well we're doing with a lack of sleep. And I think that's one of the issues that I try to sort of help dismiss in terms of a notion. I think the other thing that's problematic, too, about getting too little sleep is that your baseline level of how you think your health and your wellness is just becomes chronically low. And you accept that as if that's just where I am in life. This is just me. This is as good as it can be. And people don't realize that if you're to change something like sleep or stress or diet or physical activity, there's actually a better form of you waiting on the other side of those things. It just requires perhaps, you know, some knowledge and an invitation to go there. Matthew, I call this podcast Feel Better Live More for a reason. And it really just echoes what you just said then, you know, when we feel better by, you know, prioritizing sleep, by looking at these other pillars I talk about, we get more out of life. We're a better version of ourselves. We have better relationships. We have, you know, much deeper, more meaningful interactions with the world around us when we're feeling better. And I guess you would argue that when we sleep better, we live more. We do. I mean, firstly, that data is very clear that if you look across epidemiological studies, millions of individuals in these studies, a very simple truth comes out, which is that the shorter your sleep, the shorter your life. That short sleep predicts all cause mortality. Wow. And so, you know, I think we just need to stop and just let that sink in for a minute. Depriving ourselves from sleep will shorten our life. Yeah. Yeah. I mean, that's the powerful data that, you know, the global sleep loss epidemic that is underway right now, which I believe is probably one of the greatest public health challenges that we now face in the 21st century. It is a slow form of self-euthanasia. It's a very powerful statement, one that I absolutely would agree with. Have we, as a society, I don't know if over-prioritise is the right word. Let's go with over-prioritise. Have we put too much focus on the right food and the right physical activity at the expense of sleep? Yeah, it's a great question. I've thought about this a lot. I don't think we've done it at the expense of sleep, perhaps, but I do resonate with your comment that I think sleep has perhaps been the neglected stepsister in the health conversation of today. And I think it's been left out in the cold. There's probably a number of reasons for that. The first is just because scientists like me are to blame. What I mean is that we have not adequately communicated to the public, or to medicine, or to healthcare professionals in general, how critical the importance and necessity of sleep is. I liken where we are with sleep with where we were for smoking 50 years ago. All of the science was there, but it hadn't trickled down into the public knowledge base, or even into medicine. That's what you do so great with your book, is you're bringing that awareness to the general public all over the world, which is fantastic. And that was part of the motivation for the book. I could see the disease, and sickness, and ill health that was caused by insufficient sleep. And there wasn't a blueprint guide. There wasn't some kind of a manifesto for sleep. And so that was part of the reason to write the book. But I think to come back to why sleep is being left out in the cold, I think part of it is people like, well, at least my fault. I think the other thing, too, is that unlike diet and exercise, sleep has an image problem. You know, I think nobody feels ashamed about saying, I went out for a run at lunchtime, or, you know, I went, I had a great run this morning. Nobody necessarily feels ashamed about, you know, putting salad on their plate, you know, and making a really healthy meal. But I do think people feel sometimes ashamed by saying, I need at least eight and a half hours of sleep a night. You know, and sometimes I've heard the reaction of people saying, really? And that really has a hint in it to suggest that if you're getting sufficient sleep, and I choose that word carefully, sufficient, then you must be lazy that you're slothful. Because we've tagged and we've associated this thing called necessary sleep with that luggage of, you know, something to be ashamed about. And in fact, if anything, what happens is that people have this braggadocio attitude, this almost sort of sleep machismo attitude that you're very proud to tell people how little sleep that you're getting as though it's, you know, a badge of honor. I see that in some people, not all people, but some people. So I think to change that part of the sleep discussion and bring it into the health equation, we need to de-stigmatize sleep, in a way, too. I think those are at least two of the reasons why it's being left out in the cold. Yeah, yeah, absolutely. I mean, I, you know, I've shared this before on the podcast that a few years ago, for me, I was probably when I had kids, actually, because my kids were early risers. And, you know, that's, that's the understatement of the early risers. But I realized that if I didn't alter my going to bed time, I was going to be exhausted every single day, which is what was happening. And I sort of altered my whole sleep schedule a few years back. And it's something now that I really do prioritize, you know, I will have a shut off time in the evening, after which I'm not on my computer, I'm not working, I will wait because I know that if I don't do that, the next day, I won't be performing anywhere near the level I want to. And it actually reminds me that Facebook conversation we had the Facebook live chat we did. So guys, we were trying to schedule this chat for a little while. And I love this. Yeah, we bought a date in and then Matthew had to move, move the time. And I got an email, I think, from your publicist saying, you know, can we move this time? And I thought, well, that's 9pm UK time. That's really late. Because, you know, I've just I've just written a book saying how important sleep is as well. I'm, I'm, you know, trying to educate and inspire my audience that actually these things are really important. So I actually declined your very kind invitation to do it. And I just asked to see if we could change the time. Yeah, I certainly wouldn't have suggested. Yeah, I said, guys, look, if we chat between nine and 10. And we talk about how detrimental sleep is, and, you know, you know, and all the problems associated with it, yet we're doing it late in the evening for my UK audience. And we're, I'm going to expose everyone to blue light in the beds. I thought, actually, you know what, let's just decline that and do it another time. So yeah, that was great, wasn't it? Yeah, it was just, you know, for someone to embrace, you know, sort of practice what they preach. And, you know, and I think for the two of us, you know, a lot of people, of course, will ask me also, how much sleep do you get, and I will tell them that I do honestly get a non negotiable eight hour sleep opportunity every night. And it's I'm not trying to be, you know, a poster child for sleep. I'm not trying to just sort of promote the book. If you knew the data, as I do, and as I hope people will, after reading the book, honestly, you just would not choose to do anything else. And, you know, I don't want to live a shorter life. And I don't want to live a shorter life that is filled with with disease or sickness. And from everything I can tell sleep is perhaps one of the most democratic, freely available, efficacious forms of health insurance that you could ever wish for. And as a consequence, the reason I get that much is because for selfish reasons, you know, I just want to be alive and well for as long as possible. And I think, you know, it's interesting hearing you say why you prioritize it. You know, again, it's selfish is the wrong word, but it's for self preservation reasons. And one of the things I actually, if you don't mind, I know this is your podcast and you're interviewing me, but I would love to just ask you the question, because, you know, when I saw the title of the book, you know, and I saw that, you know, there on the front cover was this word called sleep. And it was on the front cover of your book. There was this thing called sleep, relax, eat, move and sleep. And I well imagine that the first three would be there, of course, from, you know, an eminent clinician. But I was surprised by the four. I was lovely, excited. It was wonderful. But tell me, you know, where did that decision come from to include sleep? You know, where did you get the awareness from? Where did you get the sensitivity to sleep? You know, was it boots on the ground with patients? Was it in a medical curriculum? Was it personal? Tell me. I'd love to know. Yeah, I think, Matthew, that's a great question, really. I mean, my I guess my journey into this, I've really been keen to promote lifestyle comes from a real feeling that in medicine, we've lost our way a little bit. Now, we're not putting blame on anyone. But I sort of feel that the medical system is set up around acute diseases, acute problems that respond very well to our magic bullet pharmaceutical interventions. But in the health landscape, even in my career, and I've nearly been seeing patients now for about 20 years, even in my career, I've seen the health landscape of the patients that I see change dramatically. Whereas now the bulk of what I see in my daily practice, you know, I say 80% of it is in some way driven by our collective modern lifestyles. And so I've been delving deep for a few years now in terms of, you know, what are those lifestyle factors that I can leverage with my patients to get a better outcome. And of course, when I first started going on this journey, it was all about food, right? Okay, you know, it's all about diet, you know, if we were having this chat five or six years ago, I would be saying, you know, most of our health determinant is basically foods. But I disagree now, you know, because I think when you know the science, when you have seen the science, as you detail so beautifully in your book, the case is compelling, you can't really ignore sleep. So I'm a doctor who wants to get my patients better, like every other doctor, I want to do this in as harmless a way as possible. And also get very tired of suppressing downstream symptoms. So I want to go upstream, as far as possible, see what lever can I turn, that's going to have all these downstream consequences. And food is one of those things that you know, food isn't just calories, you know, it's not just fat and carbs, it's information, it changes our genetic expression. So it's information for the body. In a similar way, physical activity can change hormones can change genetic expression, all these kinds of things. And, you know, so obviously, that's food, that's movement. Relaxation is a whole piece about stress, you know, which, you know, some research is showing that up to 90% of what we see in primary care may have stress as a factor, which is incredible. But I always thought I was missing one piece of the puzzle. And, you know, I would see like, if we take autoimmune disease for as an example, when I see my patients, I often do what's called a timeline. And I look, you know, I say, okay, you've got symptoms here today, but let's look at your whole life. Let's see what's been happening sequentially, because I don't think a lot of these chronic conditions just happen overnight, there's been a build up for a period of time for a period of years. And I would often see with autoimmune conditions that, you know, just a few months, sometimes just one month before the onset of symptoms, I would see either, either, well, not either, I would often see a really stressful episode happen that would reduce the quality of people's sleep, and then I see symptoms come on. Yeah, it was a doctor, I always want to learn from my patients. So you know, your question is, where does this come from? Well, primarily, it's come from listening to my patients and listening to the stories that they tell me. Because, you know, you're, you know, one of the world's eminent researchers of sleep. I love research, but I also love real life, what happens at the coalface when I'm seeing patients, what do they tell me is working, what do they tell me they're struggling with, that also influences a lot of my recommendations, as well as the science, you know, if you can marry those two together, I think that's when we can make a real difference with people. And I also went to a conference in San Diego, about two years ago, and the whole conference was on sleep, and relaxation, and rest, and I think it was Phyllis Zay, she gave a couple of keynotes there. I thought, this really is wetting my appetite, it's really reinforcing what I'm seeing in my practice. As I say, when you look at the research, I thought, well, how can I write a lifestyle book that is to empower people to take control of their health, and not cover sleep? You know, I can't do it, I just can't do it. What's so interesting about that is, you know, you had all of this time at medical school in practice, and it took a conference, that you, through your own sheer interest, and desire to try and help. My own sort of annual leave to go and do this, because I'm interested. That's where you got your sleep education, and you know, that strikes me as so, you know, unfortunate. You know, I want to think, I want to work with medical systems to try and increase, you know, a sleep education component, because wouldn't it be wonderful if all of our primary care physicians here in the United Kingdom were, you know, as sleep aware, and sleep motivated as you are? And I'm sure they would be delighted to receive that information. You know, I know, have lots of friends here who are doctors, and you know, I know that they would embrace that, and love to try and increase wellness in their patients. But there's just no pathway that we've engineered in the medical system to gift them with that knowledge, and dispense wellness to their patients. Because sleep really is the tide that raises all of the other health boats. It's just as you said, it's the superordinate node, that if you manipulate it, you know, it's like the Archimedes lever, you pull that, everything else, you know, can start to come into play. You get the sleep better, it affects your brain, it affects your hormones, it affects your genetic expression, it affects all these sort of things that we might be looking for drugs to, to affect those individual pathways. But you can improve a lot of them by improving your sleep. Yeah, you know, and it's no, we think, well, that sounds almost too good. But don't forget, you know, it took Mother Nature 3.6 million years to evolve this necessity of eight hours of sleep in place. Which I should note, by the way, that if you look at the data, back in the 1940s, the average adult was sleeping about 7.9 hours of sleep. Now that number here in the United Kingdom is closer to six hours and 30 minutes. In other words, within the space of 100 years, which is a blink of an evolutionary eye, we've lopped off almost 20% of our sleep need. How could that not come with demonstrable health and disease consequence? So I think, you know, there's that component there. But I love what you're saying that, you know, in medicine, we're often or even in research and pharmaceuticals, we're often trying to sort of manipulate one pathway in one area of the metabolic system on one aspect of the immune system or one feature of the cardiovascular system. And, you know, sleep affects all of those. And we can, you know, I'll give you an example. Firstly, we know that after if you get a patient and you have them sleeping just six hours for one week, this is someone, let's say, who is healthy. At the end of that one week of short sleep, their blood sugar levels are disrupted so significantly that they would be pre-diabetic, that you would diagnose them as being in a state of pre-diabetic, just from sleep deprivation, control all of the factors. You can also speak about sleep loss and the cardiovascular system. And all it takes is one hour of lost sleep, because there is a global experiment that's performed on 1.6 billion people across 70 countries twice a year, and it's called Daylight Savings Time. And it turns out that when you look at that data in the spring, when we lose an hour of sleep, we see a subsequent 24% increase in heart attacks as a result. It's just incredible. But in the autumn, you know, when we gain an hour of sleep, we see a 21% reduction in heart attacks. So the data is there on a global level. And you can even think, you speak a lot about the immune system. It's so key for our health. So tell us, what does sleep do for the immune system? So firstly, we can look on both sides of the coin. What happens when we don't get enough sleep? Firstly, we know that people who are sleeping five hours a night are four times more likely to catch a cold than those people who are sleeping eight hours or more. Striking study, very well-controlled study. We also know that it doesn't take one week of, you know, short sleep deprivation. One night is enough. What we've found is that if you take healthy individuals and then we limit them to just four hours of sleep for one single night, what we see is a 70% drop in critical anti-cancer-fighting immune cells called natural killer cells, which are these wonderful sort of immune assassins that, you know, help decrease our, you know, sort of, you know, cancer risk. Yeah. And help us fight infection. And fight infection. Of our innate immune system. Exactly. Part of that critical innate immune response. Flip the sort of the side of the coin. And now what we find is that when you get sleep, there is a change in what we call the autonomic nervous system, which is sort of this automatic part of our nervous system. And that automatic nervous system is split into two branches. One that is sort of like the accelerator pedal that gets us revved up, triggers the fight or flight response. The other is the break that sort of calms us down. And when we go into deep sleep, we apply that break to the nervous system. Everything quiets down, heart rate decreases. Deep sleep is the most wonderful form of natural blood pressure medication that you could ever wish for. But one of the other things is that we see as that nervous system quiets down levels of things like cortisol drop down, that stress-related chemical. And it's during that time that the body goes into an immune stimulation mode. And it's where essentially you're going to restock the armament of your immune army. So that when you wake up the next day, you can battle and fight infection. What's also fascinating, and I love this data, and this tells you just how critical sleep is to fighting for our health. If you look at people who become infected or you actually infect them in the experimental laboratory, let's say with sort of a cold vaccine, you immediately trigger increased sleepiness and increased amounts of deep sleep. And it turns out that the infection indicates to the immune system that you're under attack and the immune system will actually signal to the sleep system within the brain, we need more sleep. Sleep is the best battle force that we have right now to combat this assault. And so that's why when you're sick, all you tend to want to do is just curl up in bed and go to sleep. The reason is because your body is trying to sleep you well. That's an appropriate response to what's going on. Exactly. The bodies are pretty clever, right? They are remarkably clever. Again, Mother Nature has figured this out. And so she brings up this thing called sleep, which I would argue is probably like the Swiss army knife of health. Whatever ailment you are facing, it is more than likely that sleep has a tool in the box to try and help fight it. That's so key. Whatever ailment you're facing, guys, if you listen to this, whatever you're suffering from, whether it's a lack of energy on a day-to-day basis, whether it's that you're worried about your risk of developing a chronic disease such as type 2 diabetes or heart problems as you get older, what Matthew is saying, what Professor Walker is saying is that sleep, improving your quality of sleep, is going to help you with all these different facets. It's going to help reduce your risk. It's going to help increase your energy. It's also going to reduce your risk of actually getting disease in the future, which is just absolutely incredible. We are going to move on to tips, because I know many of you will be thinking, okay, this is all great. I'm hearing about all these things that sleep does, but how do I get more? We're going to come to that shortly. So much I want to talk to you about, Matthew. I mean, I think we could easily make this like a full day podcast. I'm that fascinated in this. I'd love to return at some point, should you wish me to. Yeah, well, 100%. But I think what you said about medical school training, I think it's very important, because pretty much everything that I put in here, and then the last quarter of the book is on sleep, convinced that any of that came from my medical school training. So that was all self-taught, from spending hours on PubMed, reading research, going to conferences, trying to learn more, because I wanted to help my patients more. I thought, I need to know more about this, so I can actually do my patients, give them a better service. So you're saying that maybe medical students may get maybe two hours or so, and you'd love to sort of try and help that, and get maybe a sleep curriculum into medical schools. I think one of the reasons we get on so well is there's so much synergy in our viewpoint, in terms of how we think this needs to change. So what I've done over the past six months is develop a brand new course with a colleague of mine, Dr. Panja, called Prescribing Lifestyle Medicine, and it's a one-day masterclass to teach healthcare professionals, but primarily doctors, on the basics of lifestyle medicine, if you will, as a term. So we go into sleep and we teach this framework, while they can simply apply these four pillars with their patients to start to actually implement lifestyle medicine. I'd love to maybe collaborate with you and show you the slides. I'd love to, and I've got, I teach a whole course at the University of California, Berkeley, The Science of Sleep, so I've got lots of slides I'd love to just share and do whatever I could to try and help sort of perpetuate that movement that you've got going. It's wonderful, that's exactly what we need. Yeah, and then maybe we can talk about how we get that into medical schools, and you know. Yeah, I was going to actually ask you, you know, how could we, you know, even collectively, you know, think about trying to, you know, approach sort of medicine here in the United Kingdom, and see if we could. Yeah, but we'll talk about that from the podcast, because I think that could be a great collaboration. Okay, Matthew, I know you're short on time, and again, we could just go on for so long. I was going to ask you about sleep and stress, but I think, you know, guys, for those of you listening to this, I cover that in quite a bit detail, I think, with you on my chat that's on my Facebook page, which is facebook.com forward slash DrChatterjee. So guys, you can actually check it out there, but everything that Matthew and I talk about, including that Lancet paper that he mentioned, is going to be in the show notes, which is going to be at drchatterjee.com forward slash whywesleep. There's going to be links there to everything Matthew talks about, some of Matthew's articles, his book, all kinds of things. So guys, do check that out after the podcast, and you can do a bit of further reading on those topics that interest you. So yeah, where to go to next? I mean, one thing that we do talk on that course, and I think we've not spoken about this yet, is about sleep and its role in mental health. And, you know, what's interesting, you mentioned bi-directional relationships before, and how a lack of sleep can increase our risk of problems, but also sleep can be a treatment as well for various things. And I wonder if you could talk about that in relation to mental health problems, such as anxiety and depression, and maybe from there, just move briefly on to Alzheimer's if possible? Yeah, so we've done a lot of work in this area of sort of sleep and mental health. I think the first point to note is that we have not been able to discover a single psychiatric condition in which sleep is normal. Wow. And I think sleep has a profound story to tell in our understanding, in our treatment, maybe even ultimately at some point, our prevention of grave mental illness. And I don't say that flippantly. Firstly, we've done some work where you can take healthy individuals, and you can deprive them of sleep for a single night. And then you place them inside an MRI scanner, and you look at how their brain has changed. And what we find is that these deep emotional brain centers erupt when you're sleep deprived, you become a lot more emotionally reactive, impulsive. There's a deep brain center called the amygdala, which is one of the centerpiece regions, the generation of strong emotions. That part of the brain is up to 60% more reactive when you're sleep deprived relative to when you've had a good solid night of sleep. And we've also found out- That's a huge amount, right? It's a 60%. It's very difficult to usually see that type of a change in the brain without some kind of pathology or drug. I think on an intuitive level, most people recognize it when they haven't slept well. They're just a little bit more reactive to things. That email from a boss, from their boss, for example, can be easily misinterpreted. Are they annoyed at me? You suddenly start to see things that aren't there. And I've just, I mentioned this before, I've just completed my second book called The Stress Solution, which is going to come out in January. And I cover a little bit of this that you're talking about in that to really try and show people that lack of sleep is a stress on our and 60%. That's incredible. Change in the brain. Yeah. And I think it really comes, you're absolutely right. Many of us have a sense that I just snapped dot, dot, dot. Those are the words that usually follow a bad night of sleep or when you've not got enough sleep. And we know it all the way down to the age chain. You think about a parent holding a child, the child is crying and they look at you and they say, well, they just didn't sleep well last night. As if there's some universal knowledge that bad sleep the night before equals bad mood and emotional reactivity the next day. And it doesn't stop in infancy or childhood or adolescence. It's true when we are adults as well. And we've seen this data. What I think is concerning is that that neurological signature that we discovered in that study is not dissimilar to numerous psychiatric conditions. And in fact, we're now finding significant links between sleep disruption and depression, anxiety, including PTSD, schizophrenia, and most recently and tragically suicide as well. In fact, a short sleep duration is usually predictive of either suicidal ideation, suicidal thoughts, suicide attempts, and tragically suicide completion. So I think the scope through which sleep is impacting mental health disease, I think is considerable. We used to think in psychiatry that the psychiatric disease was perhaps causing the sleep disruption. I think now we've been forced to change our minds. It's not as though it's completely in the opposite direction. It's not that every psychiatric condition is a sleep disorder. That's not true either. But is it a two-way street? I think that that's probably more tenable. In fact, is the dominant flow of traffic perhaps more in one direction than the other? I think that's also reasonable to assume on the basis of the data right now as well. So I think there's clearly an intimate relationship between our mental health and our sleep health. Matthew, the implications of what you just said, I think, are so profound. We've got to accept in the 21st century, not only do we not prioritise sleep enough, we're a chronically sleep-deprived society. We're now going through a mental health epidemic. Mind the charity here in the UK say that about one in four people in the UK now in any given year are going to be diagnosed with a mental health problem. That's incredible. And when you hear about that research, we think chronically sleep-deprived society, mental health problems otherwise, yes, there are other factors. Okay? I don't think you- Both of us agree on that. Yeah. We're not trying to say it's all to do with sleep, but what we are trying to say is that sleep is a critical part of the equation and one that we can no longer afford to ignore. So I find that research fascinating. If you enjoyed that conversation, I think you are really going to enjoy one that I had with Esther Perel, all about relationships. It's right there. So give it a click and let me know what you think. This notion sometimes that people have that you have to know yourself first, you have to love yourself first, then you can go and be in a relationship. Never made sense to me because-