A new research suggests people who sleep longer may have an increased risk of developing dementia. The study was led by Prof. Sudha Seshadri, a neurologist at the Boston University School of Medicine (BUSM), and the findings were released in the journal Neurology.
The team examined data from the Framingham Heart Study (FHS). FHS is a large study originally designed to identify risk factors for heart disease.
9 or more hours of sleep linked to greater dementia risk
For this study, a number of adults who were part of the FHS were asked to report how long they usually slept at night. The researchers then monitored the participants for 10 years to see who developed Alzheimer’s disease and other forms of dementia.
The team found that people who sleep regularly for 9 hours or more were twice as likely to develop Alzheimer’s within 10 years, compared with those who consistently spent less than 9 hours sleeping.
Additionally, as Prof. Seshadri explains, education seems to be playing a part in lowering the risk of dementia.
“Participants without a high school degree who sleep for more than 9 hours each night had six times the risk of developing dementia in 10 years as compared [with] participants who slept for less. These results suggest that being highly educated may protect against dementia in the presence of long sleep duration.”
Dr. Sudha Seshadri
The study also found that people who slept longer seemed to have smaller brain volumes. It however, cannot establish a cause-and-effect situation, but it is suspected that excessive sleep is probably a symptom rather than a cause of the brain changes that accompany memory loss. Thus, reducing sleep duration is not likely to lower the risk.
The authors believe the findings may inform future dementia and cognitive impairment detection practices. weighs in on the significance of the findings.
Co-corresponding author Matthew Pase, Ph.D., who is a fellow in the department of neurology at BUSM and investigator at the FHS, says “Self-reported sleep duration may be a useful clinical tool to help predict persons at risk of progressing to clinical dementia within 10 years.” This may inform future practices to detect the risk of dementia and other brain functional abnormalities. “Persons reporting long sleep time may warrant assessment and monitoring for problems with thinking and memory”, he adds.
The earlier a patient is identified to have dementia, the more time they and their families have to plan ahead and make important health care decisions.