Could midday napping save your life? If the experience of Greek men is any guide, the answer may be yes.

In a study released yesterday, researchers at the Harvard School of Public Health and in Athens reported that Greeks who took regular 30-minute siestas were 37 percent less likely to die of heart disease over six years than those who never napped. The scientists tracked more than 23,000 adults, finding that the benefits of napping were most pronounced for working men.

Researchers have long recognised that Mediterranean adults die of heart disease at a rate lower than Americans and Northern Europeans. Diets rich in olive oil and other heart-healthy foods have received some of the credit, but scientists have been intrigued by the potential role of napping.

The study, published in the Archives of Internal Medicine, concluded that napping was more likely than diet or physical activity to lower the incidence of heart attacks and other life-ending heart ailments. Essentially, they said, sleep at any time of day acts like a valve to release the stress of everyday life. Still, the authors cautioned that further research is needed to confirm their findings. Specialists not involved with the study said there are sound biochemical reasons to believe that a nap may help protect against heart disease.

Naps aren't generally included in the litany of good-for-your-heart lifestyle choices recommended for lowering cardiovascular risk, but they may soon be. New research suggests a midday siesta may reduce a person's risk of death from heart disease, possibly by lowering stress levels. The findings must be confirmed, but Dimitrios Trichopoulos, MD, a study author, tells us that there is little downside to taking naps .