Daytime napping habits in older adults show a statistically significant link to dementia risk, according to a 10-year study published on October 5 in The Journals of Gerontology: Medical Sciences.
Ten-Year Tracking of Napping Habits
Researchers at Johns Hopkins Bloomberg School of Public Health tracked just under 1,000 U.S. Medicare users aged 65 and older who did not have dementia at the start of the study in 2013, Yahoo Lifestyle Canada reported. Participants self-reported their napping frequency, duration, and whether naps were intentional or unintentional.
Compared to individuals who rarely or never napped, participants who napped every day or nearly every day faced a 48 percent higher risk of developing dementia. Those who napped for 30 minutes or less experienced a 40 percent higher risk.
Unintentional napping—defined as falling asleep without meaning to, such as dozing off on a couch while reading—was linked to a 39 percent higher risk. Adam Spira, senior author of the study and a professor at Johns Hopkins University, emphasized that the observational findings do not establish a direct causal mechanism.
“More frequent napping could be a marker of changes in the brain, rather than a cause of brain changes that lead to dementia.”
Spira added that daytime napping may reduce homeostatic sleep drive, the body’s natural drive for sleep that accumulates throughout the waking hours, potentially disrupting nighttime rest. Dr. Andrew Varga, a sleep neurologist and neuroscientist at the Icahn School of Medicine at Mount Sinai, said that sleepiness has been associated with abnormal accumulation of amyloid and tau proteins in the brains of otherwise healthy adults.
Daily Napping Correlates with Higher Dementia Risk
- Frequent daytime sleeping: Napping daily or almost daily correlates with a 48% higher risk of dementia, though causation is not proven.
- Unintentional dozing: Falling asleep involuntarily during the day is not normal aging and warrants medical evaluation.
- Short durations: Naps lasting 30 minutes or less showed a 40% increased risk in this cohort.
The Bidirectional Nature of Sleep and Cognitive Decline
“the relationship between sleep and dementia is undeniable, and it's also really complicated,” said Dr. Heather Elizabeth Whitson, director of the Duke Center for the Study of Aging and Human Development in North Carolina, who has no affiliation with the study. Dr. Mario Dulay, a neuropsychologist at Houston Methodist, said that many existing studies report conflicting or null results.
“Would interrupting that behavior be protective against dementia? We definitely cannot conclude that from the study,” said Dr. Heather Elizabeth Whitson, who directs the Duke Center for the Study of Aging and Human Development in North Carolina.
As abnormal proteins begin to accumulate and neurons become dysfunctional or die, regulatory centers controlling sleep-wake cycles and circadian rhythms are affected early in the disease process, Varga explained to Newsweek.
| Napping Behavior | Reported Prevalence | Associated Dementia Risk |
|---|---|---|
| Daily or near-daily napping | Cohort subset | 48% increased risk |
| Napping under 30 minutes | Cohort subset | 40% increased risk |
| Unintentional dozing | Cohort subset | 39% increased risk |
Dr. Omonigho Bubu, director of the Aging Research in Sleep Equity and Dementia Prevention program at New York University, said that sleep apnea and sleep deprivation raise dementia risk through increased production and decreased clearance of amyloid and tau proteins, heightened neuroinflammation, and altered immune function.
Involuntary Daytime Dozing Warrants Medical Evaluation
Intentional longer naps or culturally established siestas are not inherently harmful, and occasional daytime sleep after a disturbed night remains normal. However, involuntary daytime dozing is not a standard component of aging and affects approximately one-quarter of older adults according to study metrics.
Whitson emphasized that modern diagnostic pathways and therapeutic pipelines for Alzheimer’s disease involve more than 190 randomized human protocols, encouraging patients to seek timely evaluations alongside their care teams.
References
- The Journals of Gerontology: Medical Sciences: Daytime napping and risk of dementia in older adults
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