Leading neuroscientist Matthew Walker recently talked about why sleep deprivation is increasing your risk of cancer, heart attack and Alzheimer’s – and what you can do about it. See these 9 ways lack of sleep is reducing your lifespan.
#1 Risk Of Cancer
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%. Lack of sleep is linked to cancer of the bowel, prostate and breast. The World Health Organisation has classed any form of night-time shift work as a probable carcinogen.
#2 Risk Of Heart Attack & Stroke
More than 20 large scale epidemiological studies all report the same clear relationship: the shorter your sleep, the shorter your life. To take just one example, adults aged 45 years or older who sleep less than six hours a night are 200% more likely to have a heart attack or stroke in their lifetime.
#3 Rise In Blood Pressure
Even just one night of modest sleep reduction will speed the rate of a person’s heart, hour upon hour, and significantly increase their blood pressure.
#4 Risk Of Diabetes
Lack of sleep can hijack the body’s effective control of blood sugar, the cells of the sleep-deprived appearing, in experiments, to become less responsive to insulin, and thus to cause a prediabetic state of hyperglycaemia.
#5 Weight Gain
When your sleep becomes short, moreover, you are susceptible to weight gain. Among the reasons for this are the fact that inadequate sleep decreases levels of the satiety-signalling hormone, leptin, and increases levels of the hunger-signalling hormone, ghrelin.
#6 Prone To Alzheimer’s
Getting too little sleep across the adult lifespan will significantly raise your risk of developing Alzheimer’s disease. The reasons for this are difficult to summarise, but in essence it has to do with the amyloid deposits (a toxin protein) that accumulate in the brains of those suffering from the disease, killing the surrounding cells.
#7 Mental Disorder
A prevailing view in psychiatry is that mental disorders cause sleep disruption. But Walker believes it is, in fact, a two-way street. Regulated sleep can improve the health of, for instance, those with bipolar disorder. Deep sleep – the part when we begin to dream – is a therapeutic state during which we cast off the emotional charge of our experiences, making them easier to bear. Sleep, or a lack of it, also affects our mood more generally.
#8 What To Do To Ensure You Get Great Sleep?
First, you should avoid pulling “all-nighters”, at your desks or on the dance floor. After being awake for 19 hours, you’re as cognitively impaired as someone who is drunk. Second, you should start thinking about sleep as a kind of work, like going to the gym (with the key difference that it is both free and enjoyable).
“People use alarms to wake up,” Walker says. “So why don’t we have a bedtime alarm to tell us we’ve got half an hour, that we should start cycling down?” We should start thinking of midnight more in terms of its original meaning: as the middle of the night.