Tend to nap in the afternoon? A new study found a link to dementia

A decade-long observational study of about a thousand adults found a link between frequent or unplanned daytime napping and an increased risk of dementia. Daily napping raised the risk by 48%, and unplanned napping by 39%. The researchers stress that this may be an early warning sign of the disease rather than a direct cause.

A new observational study that followed about a thousand American adults for a decade found a troubling link between daytime napping and an increased risk of dementia. According to the findings, people who napped most days of the week or every day had a 48% higher risk of developing dementia, compared with those who napped rarely or not at all. The difference between planned and incidental napping is critical: adults who reported unplanned naps, meaning falling asleep by chance, had a 39% higher risk of dementia. Among those who scheduled their afternoon sleep regularly, by contrast, no clear link to increased risk was found after adjustment for other risk factors. The researchers stress that this is an observational study, and therefore shows a statistical association rather than proving causality. It is possible the link works in the opposite direction: brain changes in the early stages of Alzheimer's may damage the cells responsible for alertness, leading to fatigue and the need to nap. In that case, frequent napping is not the cause of the disease but an early warning sign. The article emphasizes that occasional napping was not found to be linked to increased risk, and that about half of the frequent nappers in the study did not develop dementia at all. Still, a significant change in sleep habits, such as moving to daily napping or involuntary falling asleep, may be a sign worth discussing with a doctor.