How long older adults sleep could affect their brain health, according to a study published Monday in the journal JAMA Neurology.
Disrupted sleep is common in late life, the study authors wrote, and associated with changes in cognitive function -- the mental capacity for learning, thinking, reasoning, problem-solving, decision-making, remembering and paying attention.
Age-related changes in sleep have also been linked with early signs of Alzheimer's disease, depression and cardiovascular disease, so the authors investigated possible associations between self-reported sleep duration, demographic and lifestyle factors, subjective and objective cognitive function, and participants' levels of beta amyloid.
Those in the study who reported short sleep duration -- defined in the study as six hours or less -- had elevated levels of beta amyloid, which "greatly increases" risk for dementia, said the study's lead author Joe Winer, a postdoctoral research fellow at Stanford University in California, via email.
That was in comparison to participants who reported normal sleep duration, which the study authors defined as seven to eight hours of sleep per night.