Bad sleep in middle age can speed up brain aging

By Stephen Beech via SWNS

Poor sleep in our 30s and 40s can speed up brain aging, warns a new study.

American researchers found that people in early middle age who suffer from sleeping issues - including having difficulty falling or staying asleep - have more signs of poor brain health in late middle age.

Study co-author Dr Clémence Cavaillès, of the University of California, San Francisco, said: "Sleep problems have been linked in previous research to poor thinking and memory skills later in life, putting people at higher risk for dementia.

"Our study which used brain scans to determine participants’ brain age, suggests that poor sleep is linked to nearly three years of additional brain aging as early as middle age.”

The study included 589 people with an average age of 40 at the start of the study.

Participants completed sleep questionnaires both at the beginning of the study and again five years later. They also underwent brain scans 15 years after the study began.

Researchers reviewed the participants’ responses to questions such as “Do you usually have trouble falling asleep?” “Do you usually wake up several times at night?” and “Do you usually wake up far too early?”

The team recorded the number of six poor sleep characteristics for each participant: short sleep duration, bad sleep quality, difficulty falling asleep, difficulty staying asleep, early morning awakening and daytime sleepiness.

The participants were divided into three groups. Those in the "low" group had no more than one poor sleep characteristic. People in the "middle" group had two to three, and those in the "high" group had more than three.

At the start of the study, around 70% were in the low group, 22% were in the middle and 8% were in the high group.

The research team examined the participants’ brain scans where the level of brain shrinkage corresponds to a specific age.

They then used machine learning to determine the brain age of each participant.

After adjusting for factors including age, sex, high blood pressure and diabetes, researchers found people in the middle group had an average brain age that was 1.6 years older than those in the low group, while those in the high group had an average brain age 2.6 years older.

Bad sleep quality, difficulty falling asleep, difficulty staying asleep and early morning awakening were the characteristics linked to greater brain age - especially when people consistently had those poor sleep characteristics over five years, according to the findings published online by the journal Neurology.

The researchers say their study doesn't prove that poor sleep accelerates brain aging, rather it only shows an "association" between poor sleep quality and signs of brain aging.

But study co-author Professor Kristine Yaffe said: “Our findings highlight the importance of addressing sleep problems earlier in life to preserve brain health, including maintaining a consistent sleep schedule, exercising, avoiding caffeine and alcohol before going to bed and using relaxation techniques.”

Yaffe, also of the University of California, San Francisco, added: “Future research should focus on finding new ways to improve sleep quality and investigating the long-term impact of sleep on brain health in younger people."