Why We Sleep: Unlocking the Power of Sleep and Dreams

Matthew Walker really, really thinks we all need some serious shut-eye, and he's not messing around when it comes to getting you on board – he hits you with both barrels on page one, and never lets up:

Routinely sleeping less than six or seven hours a night demolishes your immune system, more than doubling your risk of cancer. Insufficient sleep is a key lifestyle factor determining whether or not you will develop Alzheimer's disease. Inadequate sleep—even moderate reductions for just one week—disrupts blood sugar levels so profoundly that you would be classified as pre-diabetic. Short sleeping increases the likelihood of your coronary arteries becoming blocked and brittle, setting you on a path to cardiovascular disease, stroke, show more and congestive heart failure […] sleep disruption further contributes to all major psychiatric conditions, including depression, anxiety, and suicidality.

And this is supposed to help me sleep better!? At least before, I just used to lie there going over the same three lines from ‘I Just Can't Wait to be King’; now, if I so much as drift into momentary consciousness at two a.m., I end up paralysed with alertness, calculating the gradually rising odds that my obese, cancer-ridden body will only cease to be a concern thanks to the merciful onset of my crippling dementia.

Eventually Walker just comes right out and admits that as far as the science is concerned, ‘wakefulness is low-level brain damage’, at which point you start to wonder how far he's really going to take this whole unconsciousness thing. But by then the damage is done. Your life is different. Come evening, when Hannah is pouring herself a glass of Sancerre and playing Gaga, I now appear in the doorway in my slippers, with a hot-water bottle clutched under one arm and a toothbrush jutting from my jaws. It may feel antisocial, but anything seems preferable to inviting the heart disease, obesity, cystitis, tennis elbow and plagues of locusts that Walker is otherwise promising.

A while back I got a Fitbit, which allows me to see in appalling detail just how much sleep I sometimes fail to get – the hypnograms, with their discrete stages of slumber, never quite stretching as far as you'd like them to. Thanks to this book, it's now possible to quantify exactly what I'm missing out on during such nights, as scientists have mapped more of the neurochemical processes involved than I ever realised: the deep, NREM sleep where memories are carefully transferred from short-term to long-term memory; then the ‘informational alchemy’ of REM-sleep dreaming, which sharpens creativity and conjures up solutions to our daytime problems.

The importance of sleep can be further appraised by its evolutionary heritage – it goes back about as far as life on earth. Walker finds that even ‘the very simplest form of unicellular organisms that survive for periods exceeding twenty-four hours, such as bacteria, have active and passive phases that correspond to the light-dark cycle of our planet’. Sleep is about the first thing natural selection locked in for us, and as far as we can tell every animal does it.

One always understood that sleep was a healthy thing, but somehow a full night of it is still often viewed as a luxury. On the evidence of this book, it's more like a medical necessity. Given working practices in many parts of the world, this is a big problem, and indeed part of Walker's mission is to explain that much of the developed world is suffering from a serious, chronic sleep deficit which is ultimately ‘a slow form of self-euthanasia’ – he is talking not just to individual sleepers, but to businesses and governments who have some responsibility to take what he says into account.

The difference between a four-star book and a five-star one is that while I might love both of them, I can keep a four-star book to myself, whereas a five-star book is one I can't shut up about to everyone around me. On that basis, despite its occasional infelicities, Why We Sleep makes the grade. It's passionate and clearly written, summarises a huge amount of research about which I knew little, and addresses a subject that obviously deserves the attention. It would take someone a lot more cynical than me to read this and not silently decide to make a few lifestyle changes – on which note, if you'll excuse me, I have some intensive, hi-octane pillow time to get to. show less

Научпоп, компилирующий для обывателя последние достижения ученых, добрался и до жизненно важной и любимой нами сферы — сна. Профессор неврологии и психиатрии из Калифорнийского университета в Беркли смог донести новости науки в удобоваримой форме без формул и непонятных акронимов. Неудивительно, что книга стала бестселлером, тем более что вопрос крайне насущный.

Две трети взрослого населения всех show more развитых стран недосыпают, а последствия такого тотального недосыпа шокировали сначала ученых, а теперь, по прочтении, потревожат и вас. Всемирная организация здравоохранения вообще официально классифицировала работу в ночную смену как «вероятно канцерогенную». Без нормального сна все попытки сбросить вес тщетны — ни тренировки, ни диета не будут работать, более того, при коротком сне люди употребляют на 300 калорий больше, что в год легко дает 70 000 (с учетом выходных), а это в среднем +5 кг отнюдь не мышц. Тем, кто хвастает на работе, что им достаточно 4–5 часов сна, вы можете только посочувствовать. Это, вероятно, лишь совпадение, но и Рейгана, и Тэтчер, публично заявлявших такое, настиг Альцгеймер. Спать менее шести часов и быть годами работоспособными могут лишь люди с мутацией гена BHLHE41, а таких единицы. С другой стороны, теперь стало понятнее, как именно сон помогает мозгу учиться и закреплять навыки. Быстрый сон (со сновидениями) способствует креативности, демонстрируя смотрящему такие комбинации, которые бодрствующий мозг пресекает в зародыше. А зря, именно так появилась Yesterday «Битлз», а Отто Лёви придумал удостоенный Нобелевской премии эксперимент. Кстати, теперь с помощью сканера ученые могут понимать, что именно вы видите во сне, по крайней мере класс предметов.

Неожиданно, но сновидения, связанные с реально происходящими психологическими травмами — разводом, разрывом отношений, помогают перевернуть тяжелую страницу и войти в жизнь новых эмоций. Те же пациенты, в чьих снах не отражались мучительные переживания, не смогли отрешиться от печального события и оставались в депрессивном состоянии и год спустя. Бывает, что мы спим тревожно не из-за жизненных драм. Часто это происходит в первую ночь на новом месте. Как выяснилось, это разновидность однополушарного сна, существующего в полной мере у некоторых животных. Так, у нас одно полушарие мозга будет спать более чутко, выполняя сторожевую функцию, как, например, у птиц, сидящих в стае с краю. Качеству сна в книге вообще отведена отдельная часть. show less

What an engaging exploration into the purpose of sleep! Nature wouldn’t waste an enormous proportion of humans’ (indeed, all creatures’) daily consciousness to sleep -- and in the process put them at enormous vulnerability to predation -- unless there was enormous benefit. This book goes broad and deep into those physical and psychological benefits and the corresponding risks (physical- and mental-health problems (including dementia) and early death) associated with not getting enough sleep. (And the author shows that we’re terrible judges of whether we’re getting enough.)

It’s written by a professor of neuroscience and psychology, so while some of the substantiation is biological, more of it is via behavioral and imaging show more studies. He notes the differing needs, timing and composition of sleep in infants, children, teens, adults and seniors. He describes the hormones/chemicals that promote wakefulness or sleep, including how we hinder their effects, and stresses that alcohol and sleep meds sedate the brain, which is not sleep. Among other physical aspects, sleep regulates immunity (including the destruction of early cancers and mounting an adequate response to immunization) and metabolism (including appetite and cardiovascular health).

But it is the psychological effects that fascinated me. Early in the sleep period (I’ll call it “night”), the sleep cycles are composed predominately of non-REM (NREM) sleep, while later in the night they reverse to predominately REM sleep. NREM sleep serves to move what’s learned/experienced during the day into long-term storage; REM sleep integrates that new material with everything that’s already there; and dreaming (during REM sleep) serves to de-escalate emotions and enable creativity (thus truth in the adages to “sleep on it” and that “things will look better in the morning”). A key factor is that the brain does this work each night for the prior waking period, and when it’s impaired by poor sleep or a short sleep, there’s really no make-up opportunity.

Life-changing for me and recommended for everyone. show less

If you're someone who doesn't sleep well, or who regularly sleeps less than 7 or 8 hours per night, I'm torn between screaming at you to read this book and telling you never to go near it, as it will absolutely scare the bejesus out of you (even if you imagine that you're a pretty good sleeper).

Matthew Walker (neuroscientist and sleep specialist) doesn't beat around the bush - sleep is VITALLY important to our health, and in an age when less and less sleep seems to be impressed upon us as the norm we're collectively screwed if we don't wake up and smell the coffee (or perhaps that should be stop waking up early and smelling the coffee to try and compensate for all the work we didn't allow our brain to do overnight).

There's loads of show more fascinating stuff in here about the important, differing roles deep sleep and REM sleep play in keeping us healthy. I think of it a bit like software patch upgrades; they're needed to keep everything refreshed and working in tiptop condition, and we can ignore doing the install for a while by depriving our bodies of the sleep they need, but eventually the programme's going to stop working properly.

A few things particularly stood out for me. The link between Alzheimer's and long-term sleep problems (older people in particular suffer from much shorter amounts of deep sleep), the huge impact that even losing an hour of sleep has on your cancer fighting cells and the clinical proof of the impact shortened sleep has on our cognitive abilities. Also, the fact that humans are designed to have 2 sleep cycles per day, something which has been eradicated from most of western society, with the exception of some parts of Greece and Spain, for example, where the practice siesta is still observed (and in those parts of Greece where an afternoon nap is the norm, the average lifespan is much longer than in the USA, for example).

Walker spells it out in no uncertain terms - if you know someone who prides themselves on 'only needing 4 or 5 hours sleep' they're completely deluding themselves; we ALL need 7-8 hours sleep nightly for critical reset programmes in our brain to run properly.

My main criticism of this book is that in places Walker gets a bit long-winded and doesn't necessarily need to get lost in so much detail for a popular science book, but overall it's a really important book and one we should all read if we value our health and longevity.

4 stars - fascinating and alarming essential reading. show less

I should warn you: if you already tend towards anxiety about your health and resentment that wage labour forces you to defy your circadian rhythms, this book will worsen both. It’s a fascinating read, though, and I learned a lot about the mechanisms of sleep. Walker’s perspective is that of a research scientist, explaining with engaging enthusiasm and clarity how different aspects of sleep work, or don’t work. At the end, he presents a sort of manifesto for wider recognition of sleep’s importance. What he doesn’t do is commit to blaming neoliberal capitalism for stealing our sleep, as in [b:24/7: Late Capitalism and the Ends of Sleep|16284965|24/7 Late Capitalism and the Ends of Sleep|Jonathan show more Crary|https://images.gr-assets.com/books/1373997570s/16284965.jpg|22399975], a book I highly recommend. Walker’s final chapter argues that sleep-deprived workers are less productive, so there are financial benefits to encouraging better sleep. Unfortunately that isn't the logic of neoliberal capitalism. If profit can be extracted from sleep deprivation, and it definitely can, then it’s likely to continue. While researchers often emphasise the financial benefits of some health improvement (more sleep, exercise, vegetables, etc, etc), I can’t help feeling that these arguments are never going to have much impact. Who would these financial benefits accrue to? Mostly individual workers, who’ll have better quality of life. Who would lose out? Purveyors of junk food, sleeping pills, cars, alcohol, caffeinated drinks, diet books, and so on. Aggregate figures for ‘health savings’ are meaningless unless you consider the vested interests involved. In the case of lost sleep, there are many direct and indirect opportunities for profit. To his credit, Walker does acknowledge that individual lifestyle changes alone are hardly sufficient to deal with a global pandemic of lost sleep; the problem is systemic.

Personally, I am a total owl and this book firmly reminded me that there’s nothing to be done about that genetic legacy. Throughout my working life, I’ve depended on caffeine to function in a 9 to 5 routine. By contrast, during my PhD nobody except me cared when (or indeed if) I worked. I wrote my thesis on a midday to 8pm working routine, without caffeine or an alarm clock. As an undergraduate, I used to write essays between 8pm and 4am. Even now, I’m often wide awake at 1am, writing book reviews. Yet getting up at any time before 10am requires an alarm and coffee (the only acceptable caffeinated beverage). That said, I’ve always had a deep respect for sleep and its importance. I simply can’t get away with only six hours a night, and barely with seven. When I drag myself into work on less than six, I look and feel so awful that people comment on it. How anyone copes with that on a regular basis, I simply cannot understand. Given the chance, I sleep for nine hours or more, partially because I get so much enjoyment from dreaming. I have vivid, sometimes lucid, dreams that I usually remember. Sleep and dreaming are great pleasures of life, so its fitting that they have such importance to health and wellbeing, as Walker describes.

I must admit, ‘Why We Sleep’ did shame me into resolving to go to bed earlier (...at midnight). While I didn’t find it life-changing, there is at least one friend with a cavalier attitude to sleep that I wish to press it upon. Apparently people consistently underestimate the impact that sleep deprivation has on them. The sections on sleep’s links with brain development in babies and Alzhemer’s disease in the elderly were particularly interesting, as was the discussion of insomnia. The latter certainly made me grateful not to have genuine insomnia, which sounds hellish. It’s very rare that my brain actually forgets how to sleep. Also notable is the comment that the most ‘natural’ sleep rhythm currently known consists of one long sleep at night and a short afternoon nap. Sounds good to me, although my naps tend to take place in the early evening. Maybe one day I’ll get a job that I can do between midday and 8pm. Until then, my top tip for getting more sleep is to compress your morning routine into fifteen minutes so you can set your alarm for as late as possible. If you shower in the evenings and eat breakfast once you get to work, all you need to do before leaving the house is get dressed, comb your hair, and brush your teeth. show less

You know, I'm not usually one to tout NY Times bestsellers, but in this particular case, I want to mention that...

This kinda should be required reading for everyone.

Why? Because despite the rather innocuous title and no-nonsense factual information being presented, with no less than 750 scientific studies supporting the findings within, the author OUGHT to have been screaming that we're all freaking fools and morons.

Sure, I've heard of some of the studies, such as the ones related to the huge probability of obesity and depression and cancer rates for people who don't get 8 hours of sleep, but when we see all the other facts involved with it are all laid out, I frankly despair. Our societies are made up of complete idiots.

Most of the show more most powerful and necessary REM sleep happens in the last block of sleep, between 6-8 hours. Most of us are reducing our sleep to 6 or less. Learning and retention and memory decrease as if you're constantly drunk, and the long-term effects short circuit all rational behaviors. We eat more because we act high. We get into more car accidents. Test performance is abysmal, as is our moods, our ability to digest foods properly, and our ability to resist the flu drops from an 18% chance at 8 hours of sleep to a whopping 50% chance when you get less than 6 hours. These are studies, based on people who, in a controlled environment, are swabbed with the sick. Think about that. Add VERY significant numbers to cancer, suicide, and total life dissatisfaction, and the picture becomes very dire.

Oh, and sleeping pills short-circuit the REM cycle. As do drugs for ADHD.

This is the funniest and most horrible thing I picked up here: Teens all have a natural change in their circadian rhythm. They all become night owls. So WTF are we forcing them to get up earlier and earlier to go to school? They AREN'T getting enough sleep. So what happens? They go in, do abysmally in school, show all the same symptoms as ADHD, get diagnosed with ADHD, and then get drugs to help them concentrate while only making the fundamental problem of not getting enough REM sleep WORSE.

*slow clap*

Idiots.

And I'm talking about ALL of us. Long term sleep deprivation is the thing we do to TORTURE PEOPLE WE DON'T LIKE. And yet, there's this thing about rewarding long work cycles, turning people in unthinking zombies with decreasing work productivity JUST BECAUSE we're trying to squeeze out that last hour of work? It's KILLING US. Literally. Our minds aren't working well enough to even realize there's a problem.

Put a STOP to this! Seriously, folks! This is right up there with dancing around in a cloud of radium. Oh, look, it's so pretty!

This is science, folks. Not a fad. Don't be an idiot. show less

'Why We Sleep' is an interesting update on the current state of sleep research with a slightly tiresome polemic about the need to take sleep seriously and change our public policies to accommodate recent research findings. Let us deal with these separately.

Walker is wholly persuasive that sleep should be considered alongside nutrition and exercise as a central factor in physical and mental health and longevity. The science, mostly recent, is conclusive but has not yet percolated through wider society. This book corrects that admirably.

It changed my attitude to sleep. I strongly suggest that you, dear reader, should take time out to read the book with the probability that it will change yours too. It is, for example, decisive on the show more social mistreatment to the point of abuse of adolescents in particular.

We can take individual responsibility (frankly, if you want to live a shorter life and to have more fun that really is your business) but the social imposition of poor sleep patterns on the young and essential workers and their effect on road mortality requires wider cultural and social change.

So far I am very much on-side with Walker's science and analysis. The tiresome aspect is the way he bludgeons us when he gets to his public policy prescriptions, making us fear that we have another nannying progressive on our hands. This could deter the action that is needed!

The social problem is that progressives are engaged in a whole range of prescriptive demands at the moment. I would be sad if Walker's wise advice went the same way as adjurations to go vegan, abandon fossil fuels and other nostrums whose propagandising results in a culture of resistance.

One victim of Walker would be the night time economy on which so many local planners have been relying to reinvigorate local communities. It is an economy that provides the jobs and small businesses that keep many young workers and lower middle class families from poverty.

Similarly Walker's attitude to sleep and economic productivity still seems to consider human beings as units of production whose efficiency needs to be maximised rather than complex subjects for whom society should restructured to permit their essential humanity to thrive.

The instinctive irritation one has when engineers and scientists tell us how we should be forced to live our lives (rather than allow us to decide on the facts how we wish to do so) is minor compared to the value of the book in terms of its simple factual understanding of the importance of sleep.

Nevertheless many of the public policy prescriptions (geared to an American audience) are very sound. It would be irresponsible of public servants, healthcare professionals and politicians not to take them seriously and change current incentives and policies where they can.

The top innovations in this respect would be to change the school day to allow for normal adolescent sleep times, to reduce the long hours of essential workers, to be even tougher on drivers who fail to get adequate sleep and, in healthcare, to equalise sleep with nutrition and exercise.

If you want to be healthier, have happier and brighter children, be cognitively in better shape and live longer (and not kill yourself and others on the roads or in the air) then you will get this book, read it and change your lifestyle because it is in your interest to do so. It really is that simple. show less