Today we feature step 7 of our 10 steps to upgrade your brain.
7. Get enough sleep
On the face of it, evolution should have made sleep obsolete millennia ago: it renders us useless, passive and vulnerable for one-third of our lives, not engaged in any of the other vital functions that make us human – eating, reproducing, socialising, running billion dollar companies. It’s all too easy to conclude that sleep is for wimps.
And yet, there is a mounting body of evidence to suggest that shutting down for stretches of time outside the hours of nine and five, would make us all more, not less, competitive, smarter, healthier, happier, and more likely to stick around for the long haul.
The nature of modern life means sleep is being attacked on several fronts: our exposure to electric light and LED light, which puts a brake on our production of melatonin; caffeine; alcohol, which suppresses vital REM sleep, and prevents us laying down memories; the pull of work, and the emergence of always-on technology; lifestyle factors like longer commute times; and the phenomenon of “sleep procrastination” – or staying up much later than you should to binge on Netflix.
As a result, two-thirds of us now don’t get enough sleep – defined by the World Health Organization as eight hours. Matthew Walker, the author of the global bestselling Why We Sleep: The New Science of Sleep and Dreams, and a professor of neuroscience and psychology at UC Berkeley, suggests we all need to give ourselves sufficient “sleep opportunity time” – which he defines as eight or nine hours in bed.
Sleeping less than six or seven hours a night demolishes your immune system, more than doubling your risk of cancer.
If you get up at 7am and feel you could fall back asleep at 10am, need caffeine to get through the morning, and don’t wake up before your alarm clock, you’re probably sleep deprived, he suggests.
In his book, Walker writes that even a two-second “microsleep” behind the wheel – defined as a lapse in concentration, during which the eyelids fully or partially close, and your brain becomes blind to the outside world – is enough to cause death. Microsleeps are usually suffered by individuals who are chronically sleep restricted – getting less than seven hours a night – and sufferers are mostly unaware of them. The risk of a fatal lapse in concentration behind the wheel is just one more immediate effect of sleep deprivation.
Less well-known are the hidden costs to our memories, judgment, decision-making, creativity and long-term health. The truth is that, far from a passive state, sleep is essential for many functions: consolidating memories; learning; making logical choices and solving problems; recalibrating our emotional circuitry; fostering creativity; repairing physical damage; clearing out toxins; preventing infection; regulating our appetite; helping our microbiome to flourish; lowering our blood pressure.
“Sleep is infinitely more complex, profoundly more interesting
and alarmingly more health-relevant” than we previously understood, says Walker. “There does not seem to be one major organ within the body, or process within the brain, that isn’t optimally enhanced by sleep and detrimentally impaired when we don’t get enough.”
So what does happen when we don’t get enough sleep?
After just one night of poor sleep, your immune system is already under siege, with a 70 per cent reduction in your stores of your natural killer cells, or lymphocyte white blood cells. Your concentration suffers – in one landmark University of Pennsylvania study, a night of no sleep resulted in a 400 per cent increase in microsleeps. More alarmingly, participants who were logging a nightly six hours’ sleep were just as performance-impaired 10 days into the study, as those who had been awake for 24 hours, just as much as people who had been drinking alcohol. Both groups had a 400 per cent increase in microsleeps.
The shorter you sleeps, the shorter your lifespan
Over the longer term, chronic sleep deprivation is linked to abnormally high blood sugar levels, diabetes, cardiovascular strokes, cancer, depression, anxiety and obesity. It is one of the key lifestyle factors that determines if you’ll get Alzheimer’s. Margaret Thatcher’s habit of getting only five hours a night set the tone for a generation of politicians: less often written about are her later years, dogged by dementia and mini-strokes. “The shorter you sleep,” Walker warns, “the shorter your lifespan.”
The biological functions of sleep are complex and myriad. When we reach the fourth, deepest stage of sleep, for example, our bodies release a growth hormone in which bruises and cuts are healed, infections are fought, and cellular damage is repaired. In children and teenagers, new cells are released which enable the body to grow. During the fifth period of sleep, REM sleep, a fatty substance called myelin, which is essential for proper neural functioning, is generated in the brain. As Alex Soojung-Kim Pang puts it in his book, Rest: Why You Get More Done When You Work Less, myelin “in the brains of children and infants helps explain how they do smart things; the incomplete myelination of the prefrontal cortex in the brains of teens helps explain why they do stupid things.”
Sleep doesn’t just help our brains function: it is important for physical performance too. In one study, members of Stanford’s men’s basketball team increased their nightly sleep by an average of 110 minutes. The extra rest correlated with a 9 per cent boost in both their free-throw and three-point accuracy and a 0.7-second improvement in sprint times.
Frighteningly, most of us have no idea how sleep deprived we are. We have become acclimatised to constant, low-level exhaustion.
“Millions of individuals unwittingly spend years of their levels in a sub-optimal state of psychological and physiological functioning, never maximising their potential of mind or body.”
This post is for informational purposes only. It should not be considered therapy.This blog is only for informational and educational purposes and should not be considered therapy or any form of treatment. We are not able to respond to specific questions or comments about personal situations, appropriate diagnosis or treatment, or otherwise provide any clinical opinions. If you think you need immediate assistance, call your local doctor/psychologist or psychiatrist or the SADAG Mental Health Line on 011 234 4837. If necessary, please phone the Suicide Crisis Line on 0800 567 567 or sms 31393.
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