Harvard Study Links Napping Habits to Increased Mortality Risk

A comprehensive study conducted by researchers at Harvard Medical School and Massachusetts General Hospital involving over 86,000 adults has revealed concerning associations between specific napping habits and elevated mortality rates. The study, which utilized wearable devices to track sleep patterns over an 11-year period, found that longer, irregular, or midday-heavy naps could serve as indicators of underlying health issues, including cardiovascular and metabolic disorders.

The research, published in the Journal of Sleep Research in June 2025, tracked participants with an average age of 63. According to Dr. Chenlu Gao, the lead investigator and a researcher at Harvard Medical School, the findings suggest that certain patterns of napping could signal declining health. Gao stated, "Our findings suggest that certain patterns of napping could serve as early indicators of declining health, as longer or more irregular naps may reflect poor nighttime sleep, circadian rhythm disruption, or underlying health conditions such as cardiovascular disease, metabolic disorders, depression, or early neurodegenerative changes."

Key findings from the study identified three primary 'nap red flags': 1. **Long Naps**: Participants who napped for more than 30 minutes regularly exhibited a significantly higher mortality risk. This aligns with previous research indicating a 19-30% increased risk of death and heart disease associated with longer naps. 2. **Irregular Naps**: Those with unpredictable napping schedules showed increased mortality rates. Irregular patterns could disrupt circadian rhythms, exacerbating health issues. 3. **Midday Napping**: Surprisingly, napping most frequently between late morning and mid-afternoon was correlated with increased mortality risk, even after adjusting for various lifestyle and health factors.

Experts have long debated the health implications of napping. While short naps can enhance alertness and productivity, this study highlights that not all napping practices are equally beneficial. Previous studies, such as a meta-analysis involving 360,000 adults published in the American Journal of Epidemiology, have linked frequent napping to increased risks of hypertension and stroke.

Dr. Gao emphasized that while the study identifies correlations, it does not establish causation. "The sheer scale, objective monitoring, and consistency with past findings lend credibility: nap patterns may function as early biomarkers of declining health," she noted.

In light of these findings, health experts recommend adopting healthier napping habits. These include limiting naps to 15-30 minutes to avoid deep sleep inertia, maintaining a consistent napping schedule, and avoiding naps after 3 PM to minimize interference with nighttime sleep.

The implications of this research extend beyond individual health; they raise questions regarding public health strategies aimed at improving sleep hygiene and overall wellness. As societies increasingly embrace napping as a cultural norm, understanding its potential health risks becomes paramount.

In conclusion, while napping remains a widely accepted practice for boosting energy and productivity, this study serves as a critical reminder that the duration and timing of naps may hold significant implications for long-term health. Recognizing and addressing the nuances of napping behavior could be vital in promoting healthier lifestyles and potentially reducing mortality risks.