Leading neuroscientist Matthew Walker’s goal is to understand everything about sleep’s impact on us, from birth to death, in sickness and health. Since the last four and a half years, the sleep scientist has been working on a book called ‘Why We Sleep’, where he examines how sleep loss affects our health and in turn leads to Alzheimer’s disease, cancer, diabetes, obesity and poor mental health.
Walker says that in today’s world, people believe sleep is associated with weakness and shame. “Humans are the only species that deliberately deprive themselves of sleep for no apparent reason.” He recommends sleeping for at least eight hours a night. But to be honest, majority people get somewhere around 5-6 hours of sleep daily.
So,why are people so sleep-deprived? Walker in an interview with The Guardian says, “Light is a profound degrader of our sleep. Second, there is the issue of work: not only the porous borders between when you start and finish, but longer commuter times, too. No one wants to give up time with their family or entertainment, so they give up sleep instead. And anxiety plays a part. We’re a lonelier, more depressed society. Alcohol and caffeine are more widely available. All these are the enemies of sleep.”
Walker, 44, has been studying patterns for more than 20 years now. It was while working on his PhD that he lumbered into the world of sleep. “I was looking at the brainwave patterns of people with different forms of dementia, but I was failing miserably at finding any difference between them,” he says.
But then he read a scientific paper that described the parts of the brain, which were being attacked by different types of dementia, “Some were attacking parts of the brain that had to do with controlled sleep, while other types left those sleep centres unaffected. I realised my mistake. I had been measuring the brainwave activity of my patients while they were awake, when I should have been doing so while they were asleep.”
After he did the research, sleep became his obsession. “Only then did I ask: what is this thing called sleep, and what does it do? I was always curious, annoyingly so, but when I started to read about sleep, I would look up and hours would have gone by. No one could answer the simple question: why do we sleep? That seemed to me to be the greatest scientific mystery. I was going to attack it, and I was going to do that in two years. But I was naive. I didn’t realise that some of the greatest scientific minds had been trying to do the same thing for their entire careers. That was two decades ago, and I’m still cracking away.”
But does the professor of neuroscience and psychology at the University of California follow the 8-hours sleep rule himself? “Yes. I give myself a non-negotiable eight-hour sleep opportunity every night, and I keep very regular hours: if there is one thing I tell people, it’s to go to bed and to wake up at the same time every day, no matter what. I take my sleep incredibly seriously because I have seen the evidence. Once you know that after just one night of only four or five hours’ sleep, your natural killer cells – the ones that attack the cancer cells that appear in your body every day – drop by 70%, or that a lack of sleep is linked to cancer of the bowel, prostate and breast, or even just that the World Health Organisation has classed any form of night-time shift work as a probable carcinogen, how could you do anything else?”
He further adds that adults who are aged above 45 years and sleep less than six hours a night have a higher risk of heart attack or stroke. Lack of sleep also decreases the body’s control of blood sugar level and the body cells also become less responsive to insulin.
Sleep has a powerful effect on the immune system. If you reduce sleep even for a single night, it will drastically reduce your resilience. Less sleep means you will be more tired, thus you will be more likely to catch a cold.
However, too much sleep is equally harmful for the body “There is no good evidence at the moment. But I do think 14 hours is too much. Too much water can kill you, and too much food, and I think ultimately the same will prove to be true for sleep.”