Moment 188: The Real Reason You're Always Tired: Professor Guy Leschziner

Summary

The Diary Of A CEO with Steven Bartlett: Moment 188 Episode Title: The Real Reason You're Always Tired: Professor Guy Leschziner
Guest: Professor Guy Leschziner
Release Date: November 22, 2024

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Introduction

In Episode 188 of "The Diary Of A CEO," host Steven Bartlett engages in an insightful conversation with Professor Guy Leschziner, a renowned expert in sleep science. Over the course of nearly two decades, Professor Leschziner has dedicated his career to unraveling the complexities of sleep, its biological significance, and its profound impact on overall health and well-being.

The Fundamental Importance of Sleep

Professor Leschziner begins by emphasizing the evolutionary significance of sleep. Highlighting that humans spend approximately one-third of their lives sleeping, he underscores the paradox of our limited understanding despite its critical role.

Notable Quote:

“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.”
— Professor Guy Leschziner [00:24]

He elaborates on sleep’s intricate connection with the brain, noting that sleep is not just a passive state but a dynamic process crucial for various physiological functions. The evolution of sleep across diverse species, such as dolphins and certain birds, who have adapted to sleep with half their brains active, illustrates its critical role in survival.

Sleep and Health: A Multi-System Impact

Professor Leschziner delves into the multifaceted impact of sleep on health, explaining its influence on the immune system, cardiovascular health, blood pressure regulation, diabetes risk, mental health, and pain perception. This comprehensive overview illustrates that sleep is foundational to nearly every aspect of our daily functioning.

Notable Quote:

“The circadian rhythm... is so intrinsically linked to life itself that actually every single life form exhibits features of this 24-hour circadian rhythm.”
— Professor Guy Leschziner [02:10]

Public Perception and Awareness of Sleep

The conversation shifts to societal attitudes towards sleep. Professor Leschziner observes a positive shift over the past 15-20 years, where the importance of sleep is gaining recognition. However, he cautions that while awareness has increased, many still underestimate sleep's critical role.

Notable Quote:

“There is still in the general population an underestimation of how important sleep is.”
— Professor Guy Leschziner [04:09]

He also warns against overemphasis on achieving a perfect eight hours of sleep every night, as this obsession can lead to sleep-related anxiety and exacerbate insomnia.

Sleep Hygiene: Practices for Better Sleep

A significant portion of the discussion focuses on sleep hygiene—the behaviors and environmental factors that promote good sleep. Professor Leschziner outlines common poor sleep hygiene practices that can severely disrupt sleep quality:

• Bedroom Environment: Setting up workspaces in the bedroom or keeping the TV on disrupts the association between the bedroom and sleep.
• Electronic Devices: Exposure to screens emits blue light, which can interfere with the body’s natural sleep-wake cycles.
• Substance Use: Consuming caffeine or alcohol, especially in the evening, negatively impacts sleep quality.
• Pre-Sleep Activities: Engaging in stimulating activities, such as trading stocks late at night, hinders the ability to wind down.

Notable Quote:

“If you set up your home office in your bedroom...drink a lot of coffee late in the evening...those kinds of things. So that's, you know, the quintessential very, very bad sleep hygiene.”
— Professor Guy Leschziner [06:24]

Conversely, he suggests strategies for optimal sleep hygiene:

• Environment: Maintaining a dark, quiet, and appropriately temperature-controlled bedroom.
• Routine: Establishing a consistent wind-down period before bedtime.
• Nutrition: Avoiding large, carbohydrate-rich meals before sleep to prevent blood sugar fluctuations and reflux.

Circadian Rhythms and Light Exposure

The role of light in regulating circadian rhythms is another critical topic. Professor Leschziner explains that exposure to natural light during the day and minimizing light at night are essential for maintaining a healthy sleep cycle. He highlights the risks associated with light exposure at night, including an increased risk of diabetes.

Notable Quote:

“There was a very recent study that implied that light exposure at night increases your risk of diabetes.”
— Professor Guy Leschziner [08:31]

He acknowledges the challenge of waking up with natural light due to varying sunrise times and recommends using sleep masks as an effective solution to block unwanted light, thereby enhancing sleep quality.

Individual Differences in Sleep

Professor Leschziner touches upon individual variations in sleep needs and sensitivities. He introduces the concept of "sleep reactivity," which refers to how susceptible a person's sleep is to environmental disruptions. Those with high sleep reactivity may find disruptions like a partner’s snoring or frequent bathroom visits significantly impact their sleep quality, whereas others may not be as affected.

Notable Quote:

“If you've got very bad chronic insomnia, then suddenly putting good sleep hygiene in place, it's unlikely to fix it. But it may be that that poor sleep hygiene in the first instance gave rise or at least predisposed you to developing insomnia.”
— Professor Guy Leschziner [05:29]

Conclusion

Throughout the episode, Professor Guy Leschziner provides a comprehensive exploration of sleep, emphasizing its indispensable role in human health and the pervasive yet often misunderstood nature of sleep hygiene. His insights shed light on the delicate balance between biological necessity and environmental influences, offering listeners actionable advice to enhance their sleep quality and, by extension, their overall well-being.

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Connect with Professor Guy Leschziner:

• LinkedIn
• Research Publications

Follow Steven Bartlett:

• Instagram
• LinkedIn

Transcript

[A]

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.

[B]

Yeah, something like that, yeah.

[A]

Why?

[B]

Well, I think the first thing 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 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 in epilepsy and I do specialist clinics in general neurology. So. And sleep and the brain intersect at every single level. Of course, 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.

[A]

Is it important?

[B]

Is it important? Yeah, 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 and dolphins, that very much suggests, well, you know, that must be of great importance if it's, if sleep is 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 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 fact that the circadian rhythm, so that 24 hour cycle that a whole host of biological rhythms have, is so intrinsically linked to life itself that actually every single life form exhibits features of this 24 hour circadian rhythm tells us that this was something that was prioritized 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 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 cardiovascular system, our blood pressure, risk of diabetes, mental health, so depression and anxiety, even how we perceive pain. So it really is fundamental to every system that we rely on during our waking lives.

[A]

Having seen, you know, thousands and thousands and thousands of people that struggle with sleep that have been sent to your center, do you think the average person on the street over or underestimates the importance of sleep in their day to day life?

[B]

Well, I think it's changing. I think it was not that long ago where, you know, comments like sleep is for wimps 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 15 or 20 years whereby people have become much more aware of how important sleep is and have started prioritizing it a little bit.

[A]

So you think, where do you think we stand then? Overestimate, underestimate.

[B]

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.

[A]

Overestimate it?

[B]

Yes, I think so. I think that there is a danger at the current time that we tend to obsessionalize about sleep 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, you overemphasize the importance of getting eight or eight and a half hours sleep every night, then you actually risk problems later down the line exacerbating things like insomnia.

[A]

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. Yeah, 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 there's some sort of genetic reason why this many people are struggling with sleep. So I imagine it's just some kind of behavioral reason.

[B]

So I think that the genes that predispose to insomnia are pretty widespread. But obviously 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 behavior 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, it's unlikely to fix it. But it may be that that poor sleep hygiene in the first instance gave rise or at least predisposed you to developing insomnia.

[A]

And what is poor sleep hygiene? If I wanted to be the worst possible sleeper in the world, what would I have to do?

[B]

So I think you would probably have to set up your home office in your bedroom.

[A]

Okay.

[B]

You'd have to have, you know, your TV on in your bedroom all the time, have be surrounded by electronic devices, drink a lot of coffee late in the evening. Alcohol, drink a little bit of alcohol. So alcohol in the short term, of course is quite sedating. It's a central nervous system 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, the fact that you're probably snoring a little bit more. So alcohol is not a good thing. You know, not having a wind down period, so, you know, gambling on the stock market until 1am, switching your laptop and then trying to go to bed, those kinds of things. So that's, you know, the quintessential very, very bad sleep hygiene. What about when I. E. So 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.

[A]

Okay, what about sleeping in bed with somebody else?

[B]

Well, I think that for some people, they. And again, this goes back to no. 1 rule for everybody. You know, if you've got a sleep trait term 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 urinate 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.

[A]

I was thinking the other day, because where I've currently moved into there's no blinds or curtains in my bedroom. 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.

[B]

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 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. 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.

[A]

What if you wear a sleep mask? Does that solve it?

[B]

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.

[A]

Does that mean that the only light receptors we have are behind our eyes?

[B]

Well, I think that there was a. There were some rumors 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.

[C]

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