Study: Middle-aged people who get poor sleep could face higher risk for dementia

A study published Tuesday suggested that middle-aged people who don’t get enough sleep could face a higher risk for dementia later in life. 

The study featured in Nature Communications examined the sleeping habits of nearly 8,000 participants in Britain starting when they were 50 years old over about 25 years. Researchers concluded that those who slept six hours or less were about 30 percent more likely than those who got seven hours of sleep to develop dementia. 

The researchers used data from the Whitehall II cohort study, which started with 10,308 British civil servants in 1985 through 1988, with data collected every four to five years. 

Only 7,959 participants had data on sleep durations and other necessary variables, and 521 of that group were later diagnosed with dementia at an average age of 77.  

“We find that short sleep duration in midlife is associated with the higher risk of dementia later in life, independently of sociodemographic, behavioural, cardiometabolic, and mental health factors,” the study reads. 

Participants who had seven hours of sleep, defined as normal in the study, were more likely to be male, white, married and to have better cardiometabolic and mental health profiles. 

The researchers determined that a history of mental health disorders and a usage of sleeping pills did not account for the correlation between sleep and dementia. 

Participants reported their own sleeping hours for most of the study, except at one point when almost 4,000 people measured their sleep duration by accelerometers later in the study. Researchers labeled the measured duration as consistent with the self-reported data. 

Previous studies have found that proteins related to Alzheimer’s begin appearing about 15 to 20 years before patients endure cognitive memory and thinking issues, indicating that sleep could act as an early signal for dementia, The New York Times noted. 

One of the study’s authors Séverine Sabia told the Times that several behaviors and characteristics could affect people’s sleep or risk for dementia, including smoking, alcohol consumption, physical activity, body mass index, fruit and vegetable consumption, education level, marital status, hypertension, diabetes and cardiovascular disease.