The neuroscientist and science writer Matthew Walker describes lack of sleep as a “slow form of self-euthanasia”. His best-selling book Why We Sleepis a wake-up call for all of us, writes Jim Manson
Everyone in the book world seems to agree that Matthew Walker’s number one best-seller Why We Sleepwas the surprise publishing phenomenon of 2017.
But perhaps the real surprise was that anyone was surprised in the first place. You can barely open a newspaper or switch on the TV before being warned again about how chronically sleep-deprived we are, or how our ‘always on’ lifestyles are robbing us of our few remaining moments of restfulness and reflection, or how blue light pollution is messing with our circadian rhythms.
We are jittery, distracted, officially knackered. We already knew that. But what many of us didn’t know was just how serious the repercussions were. And that’s why Matthew Walker’s book is a such wake-up call.
Walker, professor of neuroscience and psychology at the University of California and founder of the Centre for Human Sleep Science, has immersed himself for over two decades in the new science of sleep. What he and his team have found is that sleep is “more complex, profoundly more interesting and alarmingly more health relevant” than we could have ever imagined.
In Why We Sleep, Walker doesn’t make you wait long to find out just how “alarmingly health relevant” sleep is. The full, terrifying charge sheet comes on page one. Inadequate sleep (routinely getting less than six or seven hours a night) “demolishes your immune system, more than doubling your risk of cancer”… “is a lifestyle factor determining whether you will develop Alzheimer’s disease” … “disrupts blood sugar levels so profoundly that you would be classified as pre-diabetic”… “increases the likelihood of your coronary arteries becoming blocked, setting you on a path to cardiovascular disease, stroke and congestive heart disease”.
And if that doesn’t make you want to go off and lie down, Walker adds that so-called ’short sleeping’ also contributes to “all major psychiatric conditions including depression, anxiety and suicide”. Little wonder then, that he describes lack of sleep as a “slow form of self-euthanasia”.
Sleep, a health gateway
But walker wants us to turn this thinking on its head and look upon good sleep (and getting the right quantities of it) as a gateway to optimum health and wellbeing. To do that, he says, we need to think of sleep as the “third pillar of the health trinity”, alongside diet and exercise.
Before exploring why, and how, good sleep is crucial to our health and wellbeing, Walker winds the clock back a full 500 million years. He wants to know whosleeps, and what came first – the state of wakefulness, or sleep.
The answer to ‘who sleeps?’ is simple. All of us. Without exception, all species of animal studied to date sleep – or experience something very like it. The latest science suggests that it was sleep that enabled the first complex lifeforms to emerge on Earth 500 million years ago. That’s right, sleep enabledwakefulness.
“The latest science suggests that it was sleep that enabled the first complex lifeforms to emerge on Earth 500 million years ago. That’s right, sleep enabled wakefulness”
Many of us tend to think of sleep as something we need to do to fix and repair the stresses and strains of the long hours each day that we spend awake. Walker wants us to think about sleep as an enabler, rather than a fixer.
Your rhythm’s not my rhythm
In the centre of our brain is something called the suprachiasmatic nucleus, the internal 24 hour clock that controls our circadian rhythms. Although our circadian rhythms are ‘built-in’ they are affected by lots of local environmentalcues– light, temperature, and chemical changes in the body. Additionally, each of us has a particular chronotype, our own circadian ‘personality’. These fall into three groups: the morning lark (40%), the night owl (30%) and a third group that falls between the two, but with a slight leaning towards night owl personality (making up another 30%).
The problem for night owls is that the pretty much everything about the way the modern world is structured and organized is stacked against them. Take the distinctly un-level playing field of society’s work scheduling. For Walker, this is a largely unrecognized for of punishment of the night owls, with far-reaching consequences. Not only are the owls among us forced to work our when they are functioning at sub-optimal levels, but by often having to to burn the candle at both ends they are being set up for higher levels of depression, anxiety, diabetes, cancer, heart attack and stroke.
The evolutionary explanation for our differing chronotypes is that our distant ancestors would have benefited from one group always being awake when a predator turned up at the cave door.
Brain and body reset
For Walker, sleep is the single most effective thing we can do to “reset our brain and body health each day”. As well as mitigating the chances of developing any one of an entire parade of chronic illnesses, getting a good night’s sleep is a proven memory aid – both before and after learning. It also helps enhance our ability to forget ‘parasitic memories’ (good for our mental health), while REM dream-sleep acts as an overnight balm for tired minds. Sleep also functions as an effective creative incubator.
Unfortunately an awful lot of us aren’t getting many of these benefits. In fact, an estimated two thirds of adults throughout all developed nations fail to obtain the recommended eight hours of nightly sleep.
So, what’s stopping us from sleeping? In a word, modernity. The very way that modern societies and economies are organised, together with some of the scientific advances that we most associate with human progress, have sabotaged our instinctual sleep patterns.
Let there be dark
A lot of our problems with sleeplessness stem from a single scientific breakthrough: the invention of the electric light bulb in 1879 by Thomas Edison. This one invention put an end to the natural order of so many things that governed our sleep patterns for millennia; most importantly, rising with the sun and going to sleep as darkness set in. Now we had command over dark and light. The effects were immediate. Longer working hours immediately became possible. Lighting in the home extended ‘daytime’ by hours at the both ends of the day.
The arrival of darkness signals to the suprachiasmatic nucleus that nighttime is in session, resulting in the release of vast quantities of melatonin and launching the evening ‘runway’ to sleep. When homes were flooded with artificial light this biological process was halted. Our internal clocks were effectively wound back two to three hours each evening.
“The arrival of darkness signals … that nighttime is in session, resulting in the release of vast quantities of melatonin and launching the evening ‘runway’ to sleep. When homes were flooded with artificial light this biological process was halted. Our internal clocks were effectively wound back two to three hours each evening”
Fast forward to 1997 and something happens that makes the situation a whole lot worse, the invention of blue light emitting diodes – LEDs. The light receptors in the eye that communicates ‘daytime’ to the brain are most sensitive to the short wavelength within the blue spectrum, exactly where LEDs are most powerful. It means that LEDs, and all the devices that are lit by them, have twice the harmful melatonin suppression effect as old incandescent bulbs. So, using an iPad in the hours before bedtime delays the natural rise of melatonin by a whopping three hours. But it doesn’t just delay sleep, it affects the quality of sleep, with particularly harmful effects on young, developing brains.
Another way that we have unwittingly sabotaged our natural sleep patterns is by inventing central heating. The constant, regulated temperatures that it gives us, have played havoc with our ‘thermic harmony’. “We have effectively severed our relationship with the natural rise and fall of ambient temperatures,” says Walker.
Standing in the way of progress is our collective attitude to sleep. The expectation that we can battle through on a few hours sleep a night is so throughly engrained in our modern, connected, always-on lives.
Matthew Walker is so convinced about the connection between good quality sleep and good health that he talks about prescribing sleep. But unless we can end society’s apathy to sleep, he says, we will never properly understand its rich diversity of functions. The first priority, then? “We have reclaim our right to a full night’s sleep, without the stigma of laziness”.