Under five hours of sleep a night increases serious illness risk for over-50s

Study indicates middle-aged people getting less sleep more likely to contract cancer, diabetes or heart disease

Researchers looked at self-reported sleep duration data from about 8,000 adults measured at age 50, 60 and 70. Getty Images

Adults over the age of 50 who get fewer than five hours of sleep at night are more likely to be diagnosed with diseases such as cancer, diabetes or heart disease, a study published on Tuesday showed.

Evidence from self-reported data indicates that, compared to those who slept for up to seven hours a night, those who sleep less are 30 per cent more likely to contract at least two serious illnesses over the span of 25 years.

Based on the findings, the researchers — whose study was published in medical journal Plos Medicine — recommended getting between seven and eight hours of sleep every night.

“Multimorbidity (two or more chronic diseases) is on the rise in high-income countries and more than half of older adults now have at least two chronic diseases,” said study author Severine Sabia of the University College London's Institute of Epidemiology and Health.

“This is proving to be a major challenge for public health, as multimorbidity is associated with high healthcare service use, hospitalisations and disability.”

As people get older, Dr Sabia said, their sleep habits and sleep structure change.

“It is recommended to sleep for seven to eight hours a night — as sleep durations above or below this have previously been associated with individual chronic diseases,” she added.

“Our findings show that short sleep duration is also associated with multimorbidity.”

How sleep study was constructed

As part of the study, researchers looked at self-reported sleep duration data from about 8,000 adults measured at age 50, 60 and 70.

The team found that at age 50, those who slept five hours or less had a 30 per cent greater risk of multimorbidity over the 25 years of follow-up, compared with those who slept seven hours.

At 60, those who slept five hours or less had a 32 per cent greater risk, and at 70 had a 40 per cent greater risk, compared with those getting seven hours of sleep per night.

Researchers also found that sleep duration of five hours or less at age 50 was associated with a 25 per cent increased risk of mortality.

This possibly because short sleep duration increases the risk of chronic diseases that, in turn, increases the risk of death, the scientists said.

How to sleep better

“To ensure a better night's sleep, it is important to promote good sleep hygiene, such as making sure the bedroom is quiet, dark and a comfortable temperature before sleeping,” said Dr Sabia.

“It's also advised to remove electronic devices and avoid large meals before bedtime.

“Physical activity and exposure to light during the day might also promote good sleep.”

The research was funded by the National Institute on Aging, part of the National Institutes of Health, the UK Medical Research Council, the British Heart Foundation and Wellcome.