Long Sleep Duration Linked to Higher Dementia Risk in Seniors

A new study of 2,410 adults aged 65 and older examined sleep habits and levels of a modified tau protein, a hallmark of Alzheimer’s disease. Participants who slept eight to nine hours per night showed higher tau concentrations, and those who regularly slept more than ten hours had the most pronounced increase. Researchers suggest that extended sleep may raise the probability of neurodegenerative changes associated with dementia.

The findings were published in the journal Alzheimer’s & Dementia, adding to earlier research that linked very short sleep (under five hours) with a doubled risk of dementia over five years. While causality remains unclear, the study highlights the need for further investigation into how both insufficient and excessive sleep influence brain health in older adults.