It is no mystery that a good night’s sleep and a lie-in can improve your day. But researchers are suggesting that, far from just being enjoyable, quality sleep may even add years to people’s lives.
Men who regularly sleep well could live almost five years longer than those who do not, while women could benefit by two years, research suggests. And they could also enjoy better health during their lives.
Researchers found that young people who had better sleep habits were less likely to die early. But the researchers said their findings indicated quantity of sleep was not in itself enough to achieve the possible health benefits – quality of sleep is also important.
Good sleep was based on five different factors: ideal sleep duration of seven to eight hours a night; difficulty falling asleep no more than two times a week; trouble staying asleep no more than two times a week; not using any sleep medication; and feeling well rested after waking up at least five days a week.
The findings suggested that about 8% of deaths from any cause could be attributed to poor sleep patterns.
Dr Frank Qian, an internal medicine resident physician at Beth Israel Deaconess Medical Center in Boston, America, said: “We saw a clear dose-response relationship, so the more beneficial factors someone has in terms of having higher quality of sleep, they also have a stepwise lowering of all cause and cardiovascular mortality.”
Qian, a clinical fellow in medicine at Harvard Medical School and co-author of the study, added: “I think these findings emphasise that just getting enough hours of sleep isn’t sufficient. You really have to have restful sleep and not have much trouble falling and staying asleep.”
Each sleep factor was assigned zero or one point for each, for a maximum of five points, which indicated the highest quality sleep.
Qian added: “If people have all these ideal sleep behaviours, they are more likely to live longer. So, if we can improve sleep overall, and identifying sleep disorders is especially important, we may be able to prevent some of this premature mortality.”
The researchers included data from 172,321 people with an average age of 50, 54% of whom were women, who participated in the National Health Interview Survey between 2013 and 2018. The survey looked at the health of the US population and included questions about sleep and sleep habits.
People were followed for an average of 4.3 years, during which time 8,681 died. Of these deaths, 2,610 (30%) were from cardiovascular disease, 2,052 (24%) were from cancer and 4,019 (46%) were due to other causes.
The study found that, compared with people who had zero to one favourable sleep factors, those who had all five were 30% less likely to die for any reason, 21% less likely to die from cardiovascular disease, 19% less likely to die from cancer, and 40% less likely to die of causes other than heart disease or cancer.
Dr Qian said these other deaths were probably due to accidents, infections or neurodegenerative diseases, such as dementia and Parkinson’s disease, but more research was needed.
Among men and women who reported having all five quality sleep measures (a score of five), life expectancy was 4.7 years greater for men and 2.4 years greater for women, compared with those who had none or only one of the factors.
For the current study, researchers estimated gains in life expectancy starting at age 30, but they say the model can be used to predict gains at older ages, too.
Dr Qian said: “Even from a young age, if people can develop these good sleep habits of getting enough sleep, making sure they are sleeping without too many distractions and have good sleep hygiene overall, it can greatly benefit their overall long-term health.”
More research is needed to determine why men had double the increase in life expectancy compared with women who had the same quality sleep.
One limitation of the study, presented at the American College of Cardiology’s Annual Scientific Session Together With the World Congress of Cardiology, was that sleep habits were self-reported and not objectively measured or verified.
