People who get poor sleep in their 30s and 40s might be more likely to develop memory and thinking problems a decade later, a new study warns.

Those who had the most disrupted sleep in early adulthood had more than double the odds of poor thinking performance when tested in middle age, compared to those who had the best sleep, researchers found.

At the same time, researchers found no link between the total amount of sleep people got and their brain function in middle age.

“Our findings indicate that the quality rather than the quantity of sleep matters most for cognitive health in middle age,” said researcher Yue Leng, an associate professor of psychiatry with the University of California, San Francisco.

For the study, Leng and her colleagues recruited 526 people with an average age of 40 and tracked them for 11 years.

At the beginning, participants wore a wrist activity monitor for three consecutive nights to evaluate their sleep duration and quality. They underwent this test twice, about a year apart, to produce a fair assessment of their sleep patterns.

Researchers specifically focused on sleep fragmentation, or repetitive short interruptions in a person’s sleep, by tracking times when a person tossed and turned for a minute or less while sleeping.

The participants also filled out a sleep diary, in which about 46% reported poor sleep.

A decade later, researchers asked the participants to complete tests that gauged their memory and brain power.

Of the 175 people with the most disrupted sleep, 44 performed poorly on the tests 10 years later, results show.

By comparison, only 10 of 176 people who had the least disrupted sleep performed poorly on the follow-up tests.

“More research is needed to assess the link between sleep disturbances and cognition at different stages of life, and to identify if critical life periods exist when sleep is more strongly associated with cognition,” Leng said. “Future studies could open up new opportunities for the prevention of Alzheimer’s disease later in life.”

Researchers noted that the study is observational, and cannot draw a direct cause-and-effect link between disrupted sleep and cognitive decline.

The new study was published Jan. 3 in the journal Neurology.

More information

The Sleep Foundation has more about interrupted sleep.

SOURCE: American Academy of Neurology, news release, Jan. 4, 2024

Source: HealthDay