Short Sleep in Your Fifties and Later Dementia Risk
Sleeping six hours or less a night in midlife was linked to around a 30 percent higher risk of dementia decades later.
Sleep, Brain Health, Cognition, Midlife, Longevity
Researchers followed nearly 8,000 British adults for 25 years, recording how long they slept at ages 50, 60 and 70 and tracking who went on to develop dementia.
Those who regularly slept six hours or less in their fifties and sixties had roughly a 30 percent higher risk of dementia in later life than those sleeping around seven hours, a link that held after accounting for mental health, lifestyle and heart-related factors.
Because this is an observational study relying largely on self-reported sleep, it cannot prove that short sleep causes dementia, and early brain changes can themselves disturb sleep years before a diagnosis.
Even so, the long follow-up, starting decades before most diagnoses, makes it harder to explain away.
For a woman in midlife inclined to treat sleep as negotiable, it adds weight to protecting it as part of caring for the brain over the long run.