Scientists Reveal How Much Sleep You Need For 'Successful Aging'

We all want to 'age successfully' with as few health issues as possible. A new study suggests getting more than seven hours of sleep a night could go a long way to achieving that goal.

The study involved 3,306 participants aged 45 and over, whose sleep habits were recorded in 2011, 2013, and 2015, followed by a health check five years later. The data, analyzed by a team from Wenzhou Medical University in China, showed that those who bank at least seven hours of sleep a night tend to have significantly better health later in life.

"Successful aging was evaluated in 2020 and was defined as being free of major chronic diseases, no physical impairment, high cognitive function, good mental health, and active engagement with life," write the researchers in their published paper.

By the end of the study period, only 455 individuals (13.8 percent) checked all of the successful aging criteria boxes. Of those, 307 (around two thirds) were consistently getting more than seven hours of sleep a night.

The participants were split into five groups based on their sleeping habits across the four years: long stable (8-9 hours of sleep regularly), normal stable (7-8 hours regularly), decreasing (from an average of over 8 to fewer than 6), increasing (from an average of fewer than 6 to over 8), and short stable (5-6 hours regularly).

Chances of successful aging was significantly greater among the long stable and normal stable groups (17.1 percent and 18.1 percent respectively) compared to those in the decreasing (9.9 percent), increasing (10.6 percent), and short stable (8.8 percent) groups.

"Relative to participants with the normal stable sleep duration trajectory, those with the low stable and increasing trajectory had 36 percent and 52 percent lower odds of successful aging, respectively," write the researchers.

"Participants with decreasing trajectories also exhibited lower odds, though this was not statistically significant, likely due to sample size limitations."

The team accounted for factors including weight, alcohol consumption, and sex in their analysis, though the nature of the study can't confirm a direct cause-and-effect link.

What it does offer is more evidence of the importance of consistent, extended sleep.

Previous research has also highlighted seven hours a night as a potential sweet spot for sleep and aging well. We also know there are links between sleep and protection against a wide range of physical and mental health issues.

China, where the research was carried out, has one of the fastest aging populations on the planet – but it's very much a global issue. As the world gets older, we need to ensure it stays healthy as well.

"These findings underscore that chronic sleep deprivation, as well as the patterns of increasing and decreasing sleep duration, are not mere age-related changes," write the researchers.

"Rather, they emerge as pivotal indicators of obstacles in the pursuit of successful aging."

The research has been published in BMC Public Health.