“It’s not rocket science,” says Russell Foster, explaining how most of us are deprived of sleep and in need of an early night. No, but it is neuroscience — and as Professor of Circadian Neuroscience at Oxford University, he should know.
Foster is one of the U.K.’s leading experts on sleep, and an evangelical advocate of us all getting eight undisturbed hours each night, not just to improve our physical well being but our mental health, too.
Skipping nap time can be detrimental to early childhood memory development according to a new study.
Rebecca Gómez of the University of Arizona presented her new work on how sleep enable babies and young children to learn language over time at the Cognitive Neuroscience Society annual meeting in Boston today.
“Sleep plays a crucial role in learning from early development,” Gómez says. Her research, part of a symposium on sleep and memory, examines how infants can recognize similar instances and apply previous knowledge to a new situation. Language examples include learning the same letter in different fonts, or understanding the same word said by different people. Read more…
Along with a group of other experts at Cambridge, Harvard and Surrey universities, he has put together a report on sleep and our body clocks, and one of his main conclusions is striking.
“We are the supremely arrogant species; we feel we can abandon four billion years of evolution and ignore the fact that we have evolved under a light-dark cycle,” he told the BBC.
His appeal is timely because, in recent decades, there has been a noticeable shift in attitudes. Sleep, in the eyes of many high achievers, is an impediment to success. It is, in the words of Margaret Thatcher, “for wimps.” She, famously, taught herself to live on four hours a night and this has become the template for many business figures, especially women it seems.
Helena Morrissey, not content with producing nine children and running Newton Investment, gets up at 5 a.m., “sometimes earlier,” after about five and a half hours in bed. Angela Ahrendts, the former chief executive of Burberry and once the highest-paid businesswoman in Britain (now at Apple), gets up at 4:35 a.m. She insists that she gets a headache if she sleeps for more than six hours. Dawn is, she says, “my inspirational time, my time to find peace, to watch the sun rise,” which makes her into “a better executive every morning, calmer and nicer.”
But both are trumped by Harriet Green, who this week won the Veuve Clicquot Businesswoman of the Year award. She has said: “I don’t sleep much, I never have. It’s overrated.” She claims to get up at 3:30 a.m. to answer all her emails, after no more than “three to four” hours asleep.
Dr. Simon Archer, another contributor to the report, says these non-sleepers should not become role models: “I do agree that there has been this prevailing ’you snooze, you lose’ attitude, but some short sleepers such as Thatcher may be better able to cope better on less sleep.”
Other sleep experts are skeptical of these boasts. Jim Horne, Professor of psychophysiology at Loughborough University, says: “I am sorry, I just don’t believe anyone can get by on three to four-hour sleeps without any daytime naps.”
There has been a very definite elongating of the day in most areas of modern life, not just in the business world. In the Eighties, pubs in the U.K. threw you out at 11 p.m. and shops only had one late-night opening, and that meant 9 p.m. Until First Direct came along in 1989 and launched the first “24-hour bank,” it was unheard of to call any service after 5 p.m. As recently as 1962, there were villages in Devon that did not have electricity — reading in the evening was done by gaslight or candles.
‘Six hours undisturbed is probably better than 10 hours of interrupted sleep’
Foster estimates that we are sleeping about one and a half hours less a night than we did 60 years ago, and only achieving about eight hours. This is based on U.S. data from the University of Chicago, to which Horne says: “There is no evidence at all, I’m sorry, that we are getting any less sleep in Britain than we were about 50 years ago. We’ve always had about seven hours.”
However, he does agree — along with most experts — that the quality of our sleep has declined. “The whole ’you need eight hours every night’ makes as much sense as saying everyone should wear size eight shoes. It is the quality of sleep that matters. Six hours undisturbed is probably better than 10 hours of interrupted sleep.”
One of the main causes of disturbed sleep is the increasing amount of light we are exposed to late at night — either through the electric light bulb or, possibly more damagingly, through phones, TVs or computer screens. Research has demonstrated that night-time light exposure — not least through short-wave or “blue” light emitted by screens — suppresses the production of melatonin, the major hormone secreted by the pineal gland that controls sleep and wake cycles.
Melatonin suppression has far worse consequences than a bad night’s sleep: it has also been shown to increase the risk of cancer, impair immune system function, and possibly lead to type 2 diabetes, obesity and heart disease.
As Horne points out, it is not just the physiological aspect of the light from the screen. “Sitting up waiting to see if someone answers your text, or retweets you until the small hours, can wind you up. It is so important to wind down from the busy day — switch off the TV. Remember the good old days of a mug of Horlicks?” he says.
If you have five hours’ sleep or less a night, you have a 50% likelihood of being obese
Indeed, lack of sleep — in particular because of disrupted sleep or night-working — is now associated with a hospital-worth of poor health. If you have five hours’ sleep or less a night, you have a 50% likelihood of being obese, because fewer than about six hours’ sleep increases the production of ghrelin, the so-called hunger hormone. The British Medical Journal calculated that shift work was linked to a 23% increased risk of heart attack, 24% increased risk of coronary event and 5% increased risk of stroke.
Tiredness is often overlooked as a serious problem. But in the United States it was found that 31% of drivers had fallen asleep at the wheel at some stage and that 100,000 road accidents a year were linked to sleep deprivation. Both the Chernobyl and the Challenger Space Shuttle disasters were found to be partially caused by poor judgment brought on by lack of sleep.
One of the main purposes of sleep is to allow our brains to process information we have learned during the day. “After trying to learn a task,” explains Foster, “it is smashed in sleep-deprived individuals.”
Many people are exacerbating the problem, not just through their inability to switch off at night but by turning to over-the-counter drugs to stay awake. The Tab newspaper in Cambridge, which surveyed students across 42 universities, found that one in five had taken modafinil, a drug that is used to prevent sleepiness and increase concentration, in order to help them with their academic work.
Lack of sleep is a serious public health crisis, according to Foster and many others, and one that is leading to mental health problems for many individuals. Bipolar disorder, for instance, is now proven to be preceded by sleep disruption.
‘The body clock is designed to have two sleeps a day. A long one at night and a shorter one in the afternoon’
Some are less convinced and suggest that anxiety about lack of sleep is just as serious an issue. Horne says: “The acid test is: if you are sleepy throughout the day — apart from a dip in the afternoon, which is normal — then you are sleep-deprived. If you are alert and awake, then you don’t need to worry about it.”
And, he adds, there is a solution to sleep deprivation: an old-fashioned afternoon nap. He says that we should see this not as an indulgent siesta but as a high-achieving “power nap.”
“The body clock is designed to have two sleeps a day. A long one at night and a shorter one in the afternoon,” he says, pointing out that we have evolved from an equatorial climate, where predators slow down in the afternoon. “The restorative power of a 20-minute nap in the afternoon is amazing, it can repair much of the damage caused by lack of sleep.”
There is a precedent in Britain. In the medieval era, the upper classes in particular had what was called a “fyrste sleep” at about 6 p.m., for about an hour, so they’d feel refreshed for the evening.
We may have become an arrogant species, but perhaps we should put our self-regard to good use and insist to our sleep-deprived bosses that we all need a lie-down after lunch. As Foster says: “Sleep is not an indulgence.”