Sleep timing may affect people's risk of developing dementia, study suggests

Reviewed by Emily Henderson, B.Sc.Sep 21 2022

New research published in the Journal of the American Geriatrics Society suggests that the time people go to bed and the amount of time they sleep may affect their risk of developing dementia.

In the study of 1,982 older adults in China who were free of dementia at the start of the study, 97 participants were diagnosed with dementia during an average follow-up of 3.7 years.

Risk of dementia was 69% higher in those who slept for more than 8 hours (versus 7-8 hours) and 2-times higher for those who went to bed before 9 PM (versus 10 PM or later).

"This suggests that cognitive function should be monitored in older adults who report prolonged time in bed and advanced sleep timing," the authors wrote.