International study links daytime naps over one hour to higher elderly mortality

An international team of scientists found that regular daytime napping lasting more than one hour was associated with an increased likelihood of death among older adults.

Researchers analyzed data from 4,447 residents of Vietnam, with an average age of about 70, and followed participants for four years to assess daytime nap duration and regularity, and nighttime sleep quality.

During the follow-up period the team recorded 514 deaths. The study found that those who habitually napped for an hour or more had a 39% higher likelihood of death compared with those who did not nap, and this association persisted after adjusting for nighttime sleep quality and other factors.

In contrast, short naps of less than 30 minutes, and naps lasting between 30 and 59 minutes, showed no statistically significant association with an increased risk of death.

The researchers noted that nighttime sleep quality influenced the relationship between daytime rest and deaths, but the elevated risk remained among those who habitually napped for more than an hour regardless of their nighttime sleep quality.

The study authors suggested that long naps may be a marker of underlying health problems in older adults, but they emphasized that the study does not prove that napping itself increases the risk of death; rather, it may reflect existing health disorders.