Data from the Framingham Heart Study has shown that people who consistently sleep more than nine hours each night had double the risk of developing dementia in 10 years as compared to participants who slept for 9 hours or less. The findings, published in Neurology, also found those who slept longer had smaller brain volumes.

A large group of adults enrolled in the Framingham Heart Study (FHS) were asked to indicate how long they typically slept each night. Participants were then observed for 10 years to determine who developed dementia, including dementia due to Alzheimer’s disease. Researchers then analyzed the sleep duration data and examined the risk of developing dementia.

According to the researchers the results suggest that excessive sleep may be a symptom rather than a cause of the brain changes that occur with dementia. Therefore, interventions to restrict sleep duration are unlikely to reduce the risk of dementia.

The researchers believe screening for sleeping problems may aid in the early detection of cognitive impairment and dementia. The early diagnosis of dementia has many important benefits, such as providing a patient the opportunity to more activity direct their future plans and health care décisions.

Paper: “Prolonged sleep duration as a marker of early neurodegeneration predicting incident dementia”
Reprinted from materials provided by the Boston University Medical Center.