Picture by Guilherme Tavares via Flickr, Creative Commons
"We are, as a population, sleeping less now than we ever have," wrote Maria Konnikova recently in the New Yorker. And it's not just the amount of sleep we're getting that's suffering, but its quality: in a recent survey of 38,700 British employees, only 15 percent felt refreshed by their sleep.
As Arianna Huffington and others have pointed out, this sleep crisis is a very bad thing. But it was only when researching The Great Acceleration, my new book about how technology is speeding up our lives, that I came to realise just how bad it is -- and that it's children and teenagers who are most at risk.
The main problem that most of us face is what experts call "social jet lag." Our biological clock is set not by one master circuit in the brain, but by billions of tiny clocks in every cell of our body. The reason why we get jet lag is that these separate clocks -- our alertness or digestion or light-dark perception -- drift out of synch.
Traditionally, we've seen this as a problem mostly for regular travelers, or those who work on the night shift -- something so damaging to health that it has been classified as a probable carcinogen. Experiments with junior doctors have shown that as they become sleepier, "micro-sleep" events happen all over their brains, as particular bunches of neurons shut down, to the point where they can be mostly asleep even while talking to patients, or during an operation.
But now experts believe that these problems are affecting the rest of us, too -- that the hectic pace of modern life has nudged our bodies out of synch with the day/night cycle, setting our time zone according to the office rather the sun. Till Roenneberg, a leading sleep researcher, claims that "the majority of the population in the industrialised world" is suffering from this kind of "forced synchrony."
The result is often a vicious circle. If we're sleep-deprived, we can override our bodies' need for rest by feeding more glucose into the system -- chiefly by snacking. Yet the increased sugar level in our bloodstream sends our body clocks further awry. And this affects not just our sleep, but our health, since these clocks control digestion, detoxification, DNA damage repair, circulation, cholesterol and many other processes.
In one experiment, Eve Van Cauter of the University of Chicago took two groups of young men: one was only allowed four hours of sleep a night, and the other up to ten. After a week, levels of the hunger hormone ghrelin had soared in the sleep-deprived group; carbohydrate and sugar consumption had shot up and the ability to clear glucose from the bloodstream was borderline diabetic. Without pressing the point, Van Cauter notes in the study that the rise in obesity in recent decades across society as a whole precisely mirrors the fall in sleep duration and quality.
The ultimate result of this is often what scientists call a "stimulant-sedative loop." To keep yourself awake, you rely on coffee, or Coke, or snacks. That leaves you too wired to sleep, so you resort to sedatives such as sleeping tablets or alcohol. But these don't actually increase the amount of proper sleep you enjoy -- so when you get up the next day, you need more stimulants to get you going.
This phenomenon, says Russell Foster of Oxford University, has long been seen in shift workers, but now it's found across all occupations -- and ages.
I spoke to a 13-year-old kid at a school in Liverpool and asked: "What's your sleep like?" And she said: "It's fantastic." And I said: "Wonderful, so what's your tip?" And she said: "Oh, well, I take my mother's sleeping tablets."
This is a 13-year-old child using sedatives. So I asked her: "How do you feel the next morning?" And she said: "Well, pretty groggy. But I'm OK because I've had about three Red Bulls by lunchtime." This is a massive stimulant-sedative insult to a developing, plastic brain.
The effects of such loops are, as Foster says, most alarming when it comes to children and teenagers -- both because their brains are growing and developing much more quickly than adults', and because they have different sleep needs to begin with.
Adolescents, in particular, are biologically programmed to need more shut-eye than adults. Yet the average US teenager, a study in 2010 found, sends 34 texts a night after their bedtime. The problem, says Russell Foster, "is that bedrooms now for teenagers are places of entertainment, not sleep. So a predisposition to go to bed late and get up late is enormously exaggerated by social media and other electronic devices." Many diagnoses of ADHD among children are actually the result of sleep-deprivation-induced hyperactivity.
Much of this can be blamed on parents' reluctance to provide strict rules. According to Foster:
We feel uncomfortable about providing guidelines about sleep to our young people, and they're almost crying out for it. Mood fluctuations, depression, anxiety, frustration, anger, impulsivity are all hugely augmented by lack of sleep -- you speak to these incredibly dedicated teachers and they talk about kids falling asleep for the first few hours when they come into school. This marginalisation of sleep I think is having a major impact on our health and our quality of life.
The good news, however, is that there are so many ways to fix this. We could add classes to the curriculum explaining the importance of proper sleep -- giving children gold stars for their sleep rhythms as well as their homework.
We also need to teach parents about the benefits of sleep. Something as simple as setting family rules for the consumption of media cuts the time children spend online or watching television by three hours a day. And if you don't want to give up your phone overnight, at least use filters or sunglasses to cut out the wavelengths of blue light that keep you awake and stimulated.
If all else fails, we adults should adjust our schedules to fit our children. Foster worked with the headmaster of one school in the UK to change the start of lessons from 8:50 a.m. to 10 a.m. As a result, the number of pupils meeting the government's required exam minimum thresholds went from below the national average to above it. For children from disadvantaged backgrounds, the improvement was even more dramatic: from approximately 20 percent getting decent grades to just under 40 percent.
Not getting enough sleep, we now know, is like smoking cigarettes or drinking too much -- something which is bad for us, plain and simple. But if we can learn to prioritize it, there is a huge dividend to be reaped in terms of our health and happiness.
This article is adapted from Robert Colvile's new book The Great Acceleration - How the World is Getting Faster, Faster (Bloomsbury)