Lack of sleep in middle age ‘risks’ dementia

Regularly sleeping six hours or fewer per night during middle age may be associated with a greater risk of dementia, according to a new study.

Researchers say their findings cannot establish cause and effect, but suggest a link exists between sleep duration and dementia risk.

The study suggests there is a higher risk of dementia in those sleeping six or fewer hours per night at the age of 50 to 60.

There was also a 30% increased dementia risk in those with consistently short sleeping patterns from middle to older age (from 50 to 70 years), irrespective of cardiometabolic or mental health issues (known risk factors for dementia).

Writing in Nature Communications, the authors say: “Here we report higher dementia risk associated with a sleep duration of six hours or less at age 50 and 60, compared with a normal (seven-hour) sleep duration, although this was imprecisely estimated for sleep duration at age 70.”

They add: “These findings suggest that short sleep duration in midlife is associated with an increased risk of late-onset dementia.”

The study indicates that sleep may be important for brain health in midlife and future research may be able to establish whether improving sleep habits may help prevent dementia.

While time spent sleeping is linked to dementia risk in older adults, it is unclear whether this association is also true for younger age groups.

Severine Sabia, from the University of Paris, and colleagues analysed survey data from UCL’S Whitehall II study that has examined the health of 7,959 British individuals since 1985.