New research suggests that frequent daytime napping in older adults could be a potential risk factor for dementia, as detailed in a recent study in The Journal of Gerontology: Medical Sciences.
Researchers from Johns Hopkins Bloomberg School of Public Health observed nearly 1,000 adults aged 65 and above who showed no initial signs of memory or cognitive issues when the study commenced in 2013.
A decade later, they discovered that habits surrounding daily napping—like frequency, duration, and whether the naps were taken unintentionally—were indicative of long-term brain health.
The findings revealed that those who napped regularly, defined as most days or every day, had a 48% increased likelihood of developing dementia compared to those who rarely or never napped.
Interestingly, naps that weren’t planned also seemed to heighten this risk, with participants who dozed off unintentionally facing a 39% higher risk. The duration of naps also mattered; shorter naps were correlated with less favorable health outcomes.
Napping for 30 minutes or less was associated with a 40% increase in dementia risk, even after accounting for various health factors. For naps lasting longer than 30 minutes, this association was less significant after adjusting for nighttime sleep patterns.
The research emphasized that examining daytime napping habits provides a clearer picture of overall health than just nighttime sleep metrics alone.
Study authors Adam Spira, Ph.D., and postdoctoral fellow Kening Jiang, Ph.D., noted, “Our study highlights the importance of examining not just the length of naps, but also how often and whether they are intentional.” This, they argue, can shed light on an individual’s risk for dementia.
The implications of the results persisted even when taking into account nighttime sleep duration, daytime tiredness, and sleep apnea indicators.
Spira and Jiang also pointed out that while daytime napping and nighttime sleep are interrelated, excessive daytime rest could potentially disrupt nighttime sleep, intensifying the risk of dementia.
They acknowledged that daytime napping does not inherently lead to brain changes. Instead, shifts in napping behavior could be early indicators of underlying brain issues.
In an effort to verify their findings, the researchers reanalyzed the data by excluding participants who developed dementia in the initial five years. They found that the connection between frequent, unintentional naps and dementia remained strong, implying that changes in napping habits might signal trouble years before a formal diagnosis.
Although the study was observational and had some limitations, Spira and Jiang conveyed that while they can’t conclusively say that napping causes dementia, these patterns might be significant early signals of future risks.
The researchers recommend keeping an eye on daytime napping trends, especially when they become frequent or accidental, as these may indicate health concerns worth investigating further.
