Specialists analysed sleep data from around half a million people in the UK (Picture: Getty Images)
We’ve all heard the same advice about sleep for years and years now, haven’t we? We all need to get eight hours of it a night.
It’s become one of those unshakable health rules that sits alongside drinking more (and more) water and eating five portions of fruit and vegetables a day.
Most people accept it without much argument.
But a huge study suggests that the magic number may not actually be eight after all.
Researchers examined sleep data from around 500,000 people taking part in the UK Biobank, a long-running health project in Britain. They compared participants’ reported sleep habits with measures of biological ageing throughout the body.
Their findings, published in Nature, pointed to a surprisingly narrow sweet spot.
The study suggests that sleeping between 6.4 and 7.8 hours may well be linked to slower biological ageing (Picture: Getty Images)
People sleeping between 6.4 and 7.8 hours a night appeared to age more slowly than those getting significantly more or less sleep. That link showed up across multiple parts of the body, including the brain, lungs, liver, immune system and even the skin.
Bad news, then, for anyone who treats sleep as something to quickly squeeze in between hours of in-bed doomscrolling and their snooze alarm. Or those that like to treat each night’s slumber like a mini-hibernation.
Both very short and very long sleep durations were associated with a range of health risks (Picture: Getty Images)
The study found that getting fewer than six hours a night was strongly associated with a higher risk of several health problems. These included heart failure, type 2 diabetes, anxiety and depression.
At the opposite end of the scale, sleeping for more than eight hours wasn’t linked with perfect health either.
Researchers found associations between longer sleep durations and conditions including major depressive disorder, bipolar disorder, schizophrenia, ADHD and alcohol dependency.
In short, the results suggest that there may be such a thing as _too much_ sleep.
Scientists examined how sleep patterns related to ageing across multiple organs and body systems (Picture: Getty Images)
The researchers also spotted a slight difference between men and women. Women appeared to fare slightly better with around 6.48 hours of sleep while the figure for men was 6.42 hours.
It’s not exactly a dramatic gap. Still, it matches previous findings that women may need slightly more sleep than men.
Before anyone starts setting an alarm with military precision, there are a few limitations to the research worth bearing in mind.
The study relied on people reporting their own sleep habits through questionnaires. That means some participants may have remembered incorrectly or simply guessed how much sleep they were getting.
Keeping a consistent bedtime may be just as important as the number of hours you sleep (Picture: Getty Images)
Sleep needs also vary from person to person. Factors such as age, sex and existing health conditions can all affect how much rest somebody needs.
And there’s something else worth noting. A separate study published in Sleep found that sleep regularity may matter even more than sleep duration.
Researchers reported that keeping consistent sleeping and waking times was a stronger predictor of overall mortality risk than the total number of hours spent in bed.
So while plenty of people focus on hitting a specific target each night, the bigger challenge may be sticking to a routine. It turns out that your body clock likes reliability almost as much as it likes sleep.
Comment now Comments
Add Metro as a Preferred Source on Google
Add as preferred source