Multiple new reports say certain sleep patterns—especially later daytime napping and atypical sleep duration or sleeplessness—are associated with markers of brain ageing and a higher risk of dementia.
One account draws on a study of more than 23,000 middle-aged and older adults, reporting that three midlife sleep habits track with greater white matter hyperintensity (WMH) on MRI scans. WMH appears as white patches and is commonly seen by midlife, often related to age-associated changes in small brain blood vessels. The three habits highlighted are sleeping more or less than a seven-to-nine-hour window, frequent daytime napping, and greater sleeplessness, even after adjustments for factors such as smoking status, high blood pressure, and lack of exercise.
Other coverage emphasizes findings from a Johns Hopkins study of nearly 1,000 adults over 65, part of the US Medicare programme, which followed participants for about a decade. It reports that frequent nappers and unintentional nappers show higher dementia risk, and that naps of 30 minutes or less are linked with increased odds. The outlets also note the challenge of sorting cause and effect, since dementia-related changes can also affect sleep.
