Pod Insights The Diary Of A CEO with Steven Bartlett Top Moment: The Real Reason You're Always Tired: Professor Guy Leschziner About this episode In this moment, the world-renowned expert in Neurology and Sleep Medicine, Professor Guy Leschziner outline why sleep is crucial to every aspect of your life, and the biggest mistake people make when it comes to get a good night’s sleep.
Humans spend a third of their lives sleeping, however science still understands very little about it. Guy says that sleep is of fundamental importance to humans otherwise evolution would have removed it.
Despite its importance, Guy thinks that people underestimate the power of sleep. He’s says that too often people make lifestyle choices that ensure they will have the worst possible sleep, which can then impact everything from their immune system, cardiovascular system, and mental health.
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Guy Leschziner: https://www.guyleschziner.com/
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Transcript Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.
0:03 Steven Bartlett? Why sleep? Of all the things that you could commit so much of your time to, because it appears you've been really thinking and working on the subject matter of sleep for about 20 odd years, two decades roughly?
0:12 Speaker 01 Yeah, something like that, yeah.
0:14 Steven Bartlett? Why?
0:15 Speaker 01 Well, I think the first thing is, is that we spend a third of our lives doing it, and yet, whatever people like me will tell you, we still understand relatively little about it. We understand relatively little about, you know, what it's for, what it does to our biology. Obviously, that's changing very, very quickly now. It has a great deal of overlap with the world of clinical neurology. So I also do, I do specialist clinics, specialist clinics in epilepsy, and I do specialist clinics in, in general neurology. So, and, and sleep and the brain intersect at every single level.
0:57 Speaker 01 Of course, you know, it's not me saying this, but a famous statement is, sleep is of the brain, by the brain, and for the brain. It's intimately linked to every aspect of how our brain works. So, one of the really exciting things is that because it's a relatively new area, our understanding of it is exploding in ways that are not paralleled across other areas of clinical medicine.
1:22 Steven Bartlett? Is it important?
1:24 Speaker 01 Is it important?
1:25 Steven Bartlett? Yeah.
1:26 Speaker 01 I, I think it is of fundamental importance. You know, the fact is that if sleep wasn't important, it would be a very stupid thing for evolution to create in us. The fact that we are essentially switched off from our external environment for a third of our lives. And actually, there's a whole host of evidence when you look at how certain animals have developed the ability to be able to sleep with only half their brain at a time, you know, animals like aquatic mammals or certain birds.
1:55 Steven Bartlett? Dolphin.
1:56 Speaker 01 And dolphins, that very much suggests, well, you know, that must be of great importance if it's, if sleep is... Um. A risk for our survival, because if you're an aquatic mammal like a dolphin and you're sleeping and you're unable to surface or unable to see what predators are around you, that the, that the, the evolution has designed a system whereby it enables you to sleep with half of your brain at a time. So that in and of itself tells us it's important. The, the, the, the fact that the circadian rhythm, so that twenty four hour cycle that a whole host of biological rhythms have is so intrinsically linked to life itself
2:38 Speaker 01 that actually every single um life form exhibits features of this twenty four hour circadian rhythm. Tells us that this was something that was prioritised at a very, very early stage in life's evolution on earth. So, yes, it's important. And over the last few years, we've understa- understood precisely why it's important. I say precisely, but we know that it's important for pretty much every aspect of our waking lives, be it our immune system, be it our um cardiovascular system, our blood pressure, risk of diabetes, um, uh, mental health, so depression and anxiety, even how we perceive pain.
3:19 Speaker 01 So it really is fundamental to every system that we uh rely on during our waking lives.
3:26 Steven Bartlett? Having seen, you know, thousands and thousands and thousands of people that struggle with sleep that have been sent to your centre, do you think the, the average person on the street over or underestimates the importance of sleep in their day to day life?
3:40 Speaker 01 Well, I think it's changing. I think it was not that long ago where, you know, comments like sleep is for wimps uh was heard fairly frequently and that there were some bragging rights associated with how little you sleep. I think that there has been a transformation over the last sort of fifteen or twenty years whereby people have become much more aware of how important asleep, asleep is and have started prioritising it a little bit.
4:06 Steven Bartlett? So you think, where do you think we stand then? Overestimate, underestimate?
4:09 Speaker 01 I think that there is still in the general population an underestimation of how important sleep is. But I think there are certain segments of the population that are much more aware of it. And perhaps even, dare I say, overestimate it.
4:24 Steven Bartlett? Overestimate?
4:25 Speaker 01 Yes, I think so. I think that there is a danger at the current time that we tend to obsessionalise about sleep and and think that it is the be all and end all. It's of course part of normal life for our sleep to fluctuate, depending on what's going on in our external and our internal lives. And I think the danger is that if you over emphasise the importance of getting eight or eight and a half hours of sleep every night, then you actually risk problems later down the line, exacerbating things like insomnia.
5:01 Steven Bartlett? The average person that you've treated, worked with in your clinical practice that's struggling with sleep is at the heart of the issue, just poor sort of sleep hygiene, like you've said there?
5:12 Speaker 01 Yeah.
5:13 Steven Bartlett? Because I've got so many friends that say to me that they struggle with their sleep. Many of them have struggled with it for years. And I doubt that there's some sort of genetic reason why this many people are struggling with sleep. So I imagine it's just some kind of behavioural reason.
5:29 Speaker 01 So I think that the genes that predispose to insomnia are pretty widespread. But obviously, you know, in pretty much all areas of medicine, there is an interaction between genetics and environment. And certainly, poor sleep hygiene, and that's a horrible term, I hate that term, but it's the term that is most widely used and understood, can certainly put in place certain aspects of behaviour that then can give rise to chronic insomnia in the long term. So if you've got very bad chronic insomnia, then suddenly putting good sleep hygiene in place is unlikely to fix it. But it may be that that poor sleep hygiene in the first instance
6:11 Speaker 01 gave rise, or at least predisposed you to developing insomnia.
6:15 Steven Bartlett? And what is poor sleep hygiene? If I wanted to be the worst possible sleeper?
6:21 Speaker 01 Okay.
6:22 Steven Bartlett? In the world, what would I have to do?
6:24 Speaker 01 So I think you would probably have to uh um set up your home office in your bedroom.
6:30 Steven Bartlett? Okay.
6:31 Speaker 01 You'd have to have um you know, your TV on in your bedroom all the time.
6:35 Steven Bartlett? Okay.
6:35 Speaker 01 Uh uh be surrounded by electronic devices, drink a lot of coffee late in the evening.
6:40 Steven Bartlett? Alcohol?
6:41 Speaker 01 Uh drinks a little bit of alcohol. So alcohol in the short term, of course, is is quite sedating. It's a central nervous system depress uh depressant. But it does dramatically worsen the quality of your sleep and for various reasons, the direct chemical effect, the fact that you've got a full bladder, um the fact that you're probably snoring a little bit more. So alcohol's not a good thing. Um you know, not having a wind down period. So you know, gambling on the stock market until one AM, switching your laptop and then trying to go to bed, uh those kinds of things. So that's, you know, the quintessential very, very bad sleep hygiene.
7:18 Steven Bartlett? What about when I eat?
7:19 Speaker 01 So uh you know, eating is perhaps less important, but avoiding a very large carbohydrate meal, carbohydrate-rich meal before you go to bed for two reasons. One is that we know that it can cause some fluctuations in terms of your blood sugar. And also, if you've got a bit of reflux, it can make that much worse.
7:37 Steven Bartlett? Okay. What about sleeping in bed with somebody else?
7:41 Speaker 01 Well, I think that for some people, they've, and again, this goes back to no one rule for everybody. You know, if you've got a a a sleep trait termed sleep reactivity, which is where your sleep is very liable to your environment, then obviously, sleeping next to somebody who's snoring loudly or who gets up in the middle of the night two or three times to to to urinate can be can be very disruptive to your sleep. If you've got very little sleep reactivity, you may actually find it comfortable, more comfortable to sleep with somebody in the same bed as you.
8:12 Steven Bartlett? I was um I was thinking the other day, cause where I've currently moved into, there's no blinds or curtains in my bedroom.
8:19 Speaker 01 Hmm.
8:19 Steven Bartlett? And I was wondering if that might be a good thing. Because it at least means that in terms of my circadian rhythm, I'm waking up at the same time every day. Because I'm waking up when the sun comes up.
8:31 Speaker 01 Yeah, but the sun comes up at different times, on different days firstly. So if you were doing that routinely, you might find yourself really rather sleep deprived in the summer months. And also, there is some emerging evidence that exposure to light at night in your sleep is not very good for you. So there was a very recent study that implied that light exposure at night increases your risk of diabetes. So it certainly is not good for the quality of your sleep. And the likelihood is that you won't wake up as soon as it's light, you'll wake up at an hour or so after it's got light. But during that hour or so, it may have had a negative impact on the quality of your sleep.
9:16 Speaker 01 So having a dark bedroom is really part of good sleep hygiene, as is having a quiet bedroom that is not too hot or too cold.
9:26 Steven Bartlett? What if you wear a sleep mask? Does that solve it?
9:29 Speaker 01 Yes, it does. I mean, I wear a sleep mask. I think it's, you know, particularly if you don't have good blackout curtains or blinds in your bedroom, using a sleep mask, particularly in the, in the summer months, is probably very helpful indeed.
9:42 Steven Bartlett? Does that mean that the only light receptors we have are behind our eyes?
9:46 Speaker 01 Well, I think that there was a, there were some rumours on the internet that there were light receptors elsewhere, but certainly the only ones that we know to be of significance in terms of defining our circadian rhythm are the ones in our retinas.
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