Friday, March 14, 2014

Why getting enough sleep matters

In East Asia, hard work is worn as a badge of honour and students have bragged about their all-night cram sessions, but developing brains need sleep. 

MARCH 14, 2014

Last year, an opinion-editorial that I wrote on the perils of short sleep received an unexpected flood of attention. Some wrote tongue-in-cheek commentaries on local sleep patterns. A few concerned parents made appeals on forum pages to have morning-session secondary schools start later. Others thanked me for helping them counsel their children. Is this acknowledgement that the effects of sleep on health are being taken more seriously? Perhaps not.

Independent surveys have shown that, on average, East Asian young adults sleep one to two hours less a night than their European and Australian counterparts.

In the past 12 months, more evidence regarding the growing menace of short sleep has emerged. Market research has identified midnight to 1am as ‘prime time’ for mobile usage in Malaysia. Yet, unpublished data from student surveys indicate that our elite students sleep less than five to six hours a night. Students in one school averaged less than five hours.

Developing brains need sleep. Memory consolidation — the process where what we learn is made more resistant to forgetting and interference — benefits from sleep as memories formed during the day get reactivated in deep sleep.

Data gathered from more than 120,000 people worldwide showed that adults who had the best performance in an Internet-based, standardised test set were those who reported sleeping seven hours at night.

A new finding last year found that when we sleep, channels for waste and neurotoxic substances open up by as much as 60 per cent more. Indeed, in other research, removal of beta-amyloid, a substance implicated in Alzheimer’s disease, was found to be substantially higher during sleep.


Why do many seemingly successful, motivated persons continue to give sleep the short shrift?

In East Asia, hard work is worn as a badge of honour. We know top students who have bragged about their all-night cram sessions, akin to smokers who boast it is their non-smoking friends who die from lung cancer. However, epidemiological data do not lie. Like betting against the house in a casino, most people and societies eventually lose if sleep is habitually sacrificed.

Like most good things, more hard work is not necessarily better. Beyond a point, returns for effort turn negative. Work from my lab has shown that a single night without sleep reduces the maximum rate at which one can process visual information by about a third. Our capacity to block out irrelevant, interfering information is likewise reduced and not dissimilar from that observed with cognitive ageing.

This is not to say I am decrying quality effort. On the contrary, there are productivity gains to be realised from getting adequate sleep.

Even before Twitter and Facebook, social networks exerted powerful influence on collective behaviour. About 17 years ago, it was found that the friends of overweight people had an alarming tendency to themselves be overweight. By and by, consumption norms for entire societies started shifting; ‘heavier’ has become the new normal.

The same appears to be happening for attitudes to sleep. Indeed, the nihilism I encounter when speaking to many students is troubling. Many know they are not getting enough sleep, but few seem willing to do anything about it. “I’m just going to have a short life” was the response of one student. While people have the right to lifestyle choices, if such a choice affects others and society negatively by raising healthcare costs, should governments not weigh in?

In the case of smoking, legislation has been passed to significantly reduce the risk of exposure to passive cigarette smoke. Smokers can be readily observed and cigarettes purchases can be taxed. But how are we going to reduce the costly burden of lack of sleep if corporate and government leaders themselves sleep little (perhaps as a result of favourable genetic endowment) and expect others to do likewise?


While insufficient sleep elevates the risk of death and several chronic illnesses, its effects are cumulative over long periods and are masked by other more visible risk factors. This results in sleep being downplayed when positive health tips are being dispensed.

With the advent of wearable, personalised health monitors (for example, Jawbone’s ‘UP’, an app that helps one understand how he sleeps, moves and eats so he can make smarter choices), I foresee the day when people compete to get ‘good quality’ and ‘personalised for me’ sleep.

Using sophisticated time-locked auditory stimulation applied during deep sleep, researchers have been able to boost memory performance in young adults. This may be extended to improve cognition in older people, who tend to have poorer sleep.

As biological signals to sleep and wake up later kick in when children turn 13-14 years old, secondary schools that start one hour later might find their average students improving test scores.

If health warnings fail, we can exploit vanity concerns. Research sponsored by Estee Lauder suggests that the skin of sleep-deprived young women shows less resilience to stresses such as ultraviolet light and ages prematurely. Beauty sleep has value! And when there are fortunes to be made, sleep can be commercialised just like the exercise industry.

If you are sleeping one to two hours longer on rest-days than on workdays, you are probably not getting enough sleep. If you fall asleep at work or in class regularly, your brain is telling you something.

Even for the die-hard, utility maximising economist, where sleep is concerned, the only bargains on offer are Faustian ones. Similar to exercise and good diet, improving sleep duration and quality can improve productivity, short-term well-being, long-term health and ultimately the economy. Nothing to sniff at, and lots to sleep over!


Michael Chee is Professor at the Neuroscience and Behavioral Program at Duke-NUS Graduate Medical School and a National Medical Research Council STaR Investigator. This commentary was written to commemorate World Sleep Day on March 14 on behalf of the Singapore Sleep Society.

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