Sorry sleep lovers. Getting too much sleep may predict the risk of developing dementia.
A study from the journal Neurology found prolonged sleep was an early marker of the disease. Researchers say both too much and too little sleep can have the same effect.
Evidence from other studies in the past have found associations between both long and short sleep duration and an increased risk of dementia, but it remains unclear if sleep duration is a risk factor or a marker for dementia.
To evaluate the association neurology professor at Boston University School of Medicine Sudha Seshadri, MD, evaluated sleep duration in 2,457 adults taking part in the Framingham Heart Study.
Participants told researchers how long they normally slept each night. The researchers then observed them for 10 years to see who developed Alzheimer’s disease and other forms of dementia. During the study, 234 patients developed all-cause dementia. Researchers linked longer sleep duration with a higher risk of incident dementia; their findings were largely driven by people with baseline mild cognitive impairment as well as those without a high-school degree.
Researchers also found links between longer sleep periods and brain size and poorer cognitive ability.
“Self-reported sleep duration may be a useful clinical tool to help predict persons at risk of progressing to clinical dementia within 10 years. Persons reporting long sleep time may warrant assessment and monitoring for problems with thinking and memory,” said Matthew Pase, PhD, fellow in the neurology department of Boston University School of Medicine.