Dementia risk 48% higher with popular daytime habit

A Johns Hopkins study has found that older adults who nap during the day face a markedly elevated likelihood of developing dementia, challenging the assumption that daytime dozing is simply a benign consequence of aging. For seniors hoping to preserve cognitive health, the usual advice includes staying physically active, steering clear of cigarettes, monitoring blood pressure, safeguarding hearing, receiving vaccinations and enjoying music. Yet a routine followed by anywhere from one-third to one-half of people over 65 may undermine those protective habits. Daytime napping is widespread among the elderly. According to researchers, this may stem from more fragmented and shallower sleep at night, which triggers the urge to rest when energy flags during daylight hours. Naps can function much like a cup of coffee, enhancing energy, alertness and productivity — and more than one in three younger adults also nap daily. Often regarded as an innocuous and inevitable feature of aging, napping may not be so neutral after all. The new study indicates that how often, how long and how spontaneously older adults nap could shape their dementia odds.

Frequency and Risk

Compared with those who seldom or never napped, participants who napped most days or daily faced a 48% higher risk of developing dementia across 10 years, the researchers found. Frequent nappers also tended to have higher BMIs, more health conditions, stronger depressive symptoms and greater daytime sleepiness. They were more likely to be men as well. Frequency alone did not capture the whole picture. Unintentional napping carried a 39% higher risk of dementia. Duration mattered too: snoozes shorter than 30 minutes were linked to a 40% higher risk. Separate research has tied longer naps to cognitive decline.

Marker, Not Cause

The Johns Hopkins team does not conclude that napping causes dementia. “More frequent napping could be a marker of changes in the brain, rather than a cause of brain changes that lead to dementia,” said study author Adam Spira. The connection is probably more intricate. Napping might influence dementia risk, while brain regions degenerating during dementia could drive more frequent napping. To rule out the possibility that increased napping was merely an early symptom, the researchers analyzed their data after excluding patients diagnosed with dementia within the study's first five years. The same pattern emerged: more frequent napping and shorter naps were associated with higher dementia risk later on. This suggests the heightened napping habits surfaced years before an official diagnosis. “Monitoring napping behaviors could serve as an early and accessible marker to help identify older adults at higher risk for dementia and guide targeted interventions for dementia prevention,” said author Kening Jiang. Although napping may one day serve as a dementia marker, the researchers do not believe the relationship is causal. They note that napping could be a modifiable risk factor, meaning future studies might determine whether altering napping habits helps reduce the risk of developing the condition.