New research from Greece suggests that a midday nap may be good for the heart, particularly while you're at work.
The study, published Monday in the Archives of Internal Medicine, found that siestas reduced the risk of death from heart disease by about a third among men and women.
Among working men, those who took midday naps occasionally or regularly had a 64 percent lower risk of death from heart disease than those who did not nap, while non-working men who napped had a 36 percent reduction in risk. Researchers think the same effect is true for working women, but the sample of working women who died from heart disease in the study (six out of 48 total female heart deaths) was too small to analyze.
Researchers led by Androniki Naska of the University of Athens Medical School and Dimitrios Trichopoulos, a professor of cancer prevention and epidemiology at Harvard School of Public Health, followed 23,681 Greek men and women ages 20 to 86 (although most were in their 50s) for an average of 6.32 years.
None of the participants had a history of heart disease or any other severe medical condition when they were enrolled between 1994 and 1999. At the beginning of the study, all the subjects were asked if they took midday naps, and if so, how often and for how long. They also reported their level of physical activity and diet over the past year.
A total of 792 participants died during the follow-up period, including 133 who died from heart disease. After taking into account their other heart-risk factors, the researchers calculated the impact of the naps.
Overall, those who took naps of any frequency and duration had a 34 percent lower risk of dying from heart disease than the non-nappers. Systematic nappers _ those who snoozed for 30 minutes or more at least three times a week _ had a 37 percent lower risk of heart-related death.
The researchers note that siestas are common in the Mediterranean region as well as in many Latin American countries, and that those countries tend to have low death rates from heart disease. Earlier studies had looked at this relationship with mixed results, but Trichopoulos said this was the first large, forward-looking study of the phenomena that took into account diet and physical activity.
"I'd say the public health message is clear _ if you can take a midday nap at work, do so," Trichopoulos said.
Medical researchers have a number of theories about sleep and heart disease, including that getting more sleep generally supports a healthier lifestyle in terms of diet and exercise.
But the Athens-Harvard team attributes the positive effect to the "stress-reducing consequences" of taking a consciousness break from the workplace, thus reducing levels of stress hormones in the bloodstream that are known to be tough on the heart.
The fact that the protective effect of naps was stronger on working men, who presumably face more stress, than non-working men seems to support this theory, they wrote.