Why tossing and turning at night could increase risk of cognitive decline: study

Tossing and turning could mean more than just a night of poor sleep.

New research suggests that middle-aged people who experience interrupted sleep could be at an increased risk of developing memory and cognitive issues later in life.

The study, published Wednesday in the journal Neurology, found that those with the most disrupted sleep were at double the risk of cognitive decline than those who had the least sleep disruption.

“Given that signs of Alzheimer’s disease start to accumulate in the brain several decades before symptoms begin, understanding the connection between sleep and cognition earlier in life is critical for understanding the role of sleep problems as a risk factor for the disease,” study author Dr. Yue Leng, from the University of California, San Francisco, said in a statement.

“Our findings indicate that the quality rather than the quantity of sleep matters most for cognitive health in middle age.”

The researchers analyzed the sleep quality and duration of 526 people with an average age of 40 and followed them for 11 years. The participants wore an activity monitor on their wrists for three days on two separate occasions about a year apart to determine their average sleep duration, which was about six hours.

In addition to the wrist monitors, the volunteers also self-reported when they went to bed and woke up and completed memory and cognitive testing.

Additionally, the researchers analyzed the amount of “sleep fragmentation” participants experienced, measuring how much time snoozers spent moving and lying still, finding that the average percentage of sleep fragmentation was 19%.

Volunteers also submitted a sleep quality questionnaire with scores ranging from 0 to 21 — the higher the score, the poorer the sleep — and were grouped into three categories by score. Slightly less than half of the participants, 239 people, reported a score higher than five.

Out of 175 participants with the most disrupted sleep, 44 of them performed poorly on cognitive exams a decade later compared to 10 out of 176 people with the least interrupted slumber.

However, more research is needed to further analyze the potential link between interrupted sleep and cognitive decline later in life, Leng explained.

“Future studies could open up new opportunities for the prevention of Alzheimer’s disease later in life,” Leng said.

Poor sleep and sleep deprivation can be detrimental to your health, past research has shown.

A recent study, which analyzed 154 reports on sleep, found that just a loss of one to two hours of shut-eye could have a negative impact on mental health.