Frequent, unintentional napping in older adults was associated with a higher risk of dementia in a study led by researchers at Johns Hopkins’ Bloomberg School of Public Health. The findings do not establish that napping causes dementia or that avoiding naps prevents it.
The study followed nearly 1,000 adults aged 65 and older for 10 years. None had dementia when the research began. Participants reported how often and how long they napped, and whether they fell asleep intentionally.
Compared with participants who rarely or never napped, those who napped daily or nearly daily had a 48% higher risk of developing dementia. Naps lasting less than 30 minutes were associated with a 40% higher risk, while unintentional naps were associated with a 39% higher risk.
Researchers cautioned that increased napping could reflect underlying brain changes rather than cause them. The study also relied on participants’ recollections, which may be inaccurate. Outside experts noted that other studies have reported different findings or no association.
The relationship between sleep and dementia is complex. Poor nighttime sleep may contribute to dementia risk, while neurodegenerative changes may also disrupt sleep, according to Dr. Heather Elizabeth Whitson, a Duke University aging researcher who was not involved in the study.
The findings do not mean older adults need to stop taking planned naps. Whitson said occasional naps after disrupted sleep, or naps taken as part of a cultural routine, were not shown by this research to be harmful.
However, frequently falling asleep unintentionally during the day warrants discussion with a doctor, Whitson said. Such sleepiness may signal a treatable condition, including obstructive sleep apnea, rather than dementia. She emphasized that evaluation can help identify the cause and allow patients, families and clinicians to consider appropriate treatment and safety measures based on the individual’s circumstances and health needs.