In 1946, Randy Gardner participated in a Stanford University study to assess how long humans could go without sleep and whether there were any ill effects. After 11 days and 25 minutes, he finally fell asleep. Waking after a 14-hour nap, he claimed that staying awake for so long had no adverse effects. The researchers, however, thought otherwise, noting that he had suffered from short-term memory loss, paranoia and hallucinations.
While it seems clear that depriving yourself of sleep for such an extended period could not be good for you, the question is, are we all depriving ourselves of much-needed sleep on a daily basis?
While sleep needs vary, short sleep duration is defined as less than seven hours per night. On average, 35 per cent of adults sleep less than seven hours per night. Beyond feeling less than well-rested, the question is whether it has any other negative consequences. As a cardiologist interested in helping people prevent heart disease and live longer, my view on this is clear.
Yes.
While Randy Gardner was not trying for a Guinness world record for staying awake, attempts were banned in 1977 because of the inherent dangers.
According to Netflix, sleep is its biggest competitor
By comparison, though, there are still ongoing record attempts at holding live rattlesnakes in your mouth - it’s 13, in case you were wondering - and how many bees you can cover yourself in, a frightening 637,000. In the eyes of the Guinness World Record committee, these feats hold an “acceptable” risk of being reattempted compared to depriving yourself of sleep for long periods. That should tell you all you need to know.
But what about the impacts of shortened sleep on health? Even four nights of shortened sleep can move people closer to becoming insulin resistant, the precursor state to diabetes. Shortened sleep is also linked to higher rates of high blood pressure, plaque build-up in the heart arteries, heart attacks and strokes. Your efforts at dieting can also be seriously thrown off by shortened sleep. People who have shortened sleep routinely eat 270 calories per day more on average. Even those who do manage to reduce their calorie intake are less likely to lose weight, and more of that weight is likely to be muscle and not fat.
One of the biggest challenges of shortened sleep is its impact on mood and cognitive wellbeing. Recent evidence suggests that high levels of physical activity are linked to lower rates of dementia, except in those who are routinely sleep-deprived. So, for all of you exercising for the cognitive benefits, you might not be getting the gains you should be getting.
The biggest challenge with getting more sleep is that the world incentivises you not to. According to Netflix, sleep is its biggest competitor. With endless competition for our attention, we all know the feeling of staying up that bit later because we want to watch just one more video or extra episode. What’s “just one more episode?” Well, studies of those who had the highest amounts of night-time light exposure show a 20 to 30 per cent increased odds of dying prematurely compared to those with much less night-time light exposure.
Most people don’t even realise that they are currently part of the world’s biggest experiment on sleep, and here, I’m not talking about smartphones. Twice a year, the clocks change by one hour, either giving us one additional hour of sleep or taking one away. When we lose one hour of sleep, the rates of heart attacks increase by 24 per cent. When we gain it back, they come back down, but only by 21 per cent. There is even some evidence to suggest that rates of suicide increase and that judges give harsher sentences when daylight savings changes result in an hour less sleep. So even if your phone doesn’t steal your sleep, daylight savings time just might.
Some people need very little sleep because they carry certain genes that limit their need for sleep, but these gene defects are rare. Others will claim that some of the greatest figures in history got by on very little sleep: Winston Churchill, Bill Clinton and Margaret Thatcher, to name a few. My response to this claim is simple: Bill Clinton had a triple bypass at age 58, Margaret Thatcher developed dementia in her early 70s, and Winston Churchill had his first of 8 strokes in his mid-70s. I’m not saying sleep was the only factor here, but you will need to get some better examples if you are going to try to convince me.
To get more sleep, you simply need to stick to the fundamentals. You probably don’t need supplements, and I strongly advise against sleeping tablets. Most people need to go to bed and get up at exactly the same time every single day – yes, that includes weekends. This will train your circadian rhythm to work with you and not against you. Changing time zones interrupts your circadian rhythm, but so does staying up two hours later, which is why we call it social jet lag. Charging your phone in another room, investing in blackout blinds, and keeping your room cool will all help you get a good night’s sleep.
These simple changes have the biggest impact on sleep. Do I think that a few nights of shortened sleep will damage your health? No. Do I think a few decades will? Yes. You don’t need to set any world records; you just need about 7 to 9 hours most nights.
Dr Paddy Barrett is a preventive cardiologist at the Blackrock clinic and author of Heart An Owner’s Guide
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