U.S. epidemiologist Dimitrios Trichopoulos (Harvard University) and Greek epidemiologist Androniki Naska (Athens Medical School) monitored over 23,000 healthy Greek citizens over a six-year period of time to find if midday naps had any affect on people's mortality. Just over 50% of the test subjects took regular midday naps while the other half stayed awake throughout the day.
The researchers controlled for factors of body mass index, diet, smoking, and other such issues. The people who napped during the day had about a 37% lower death rate from coronary death than that of the non-nappers. Working men showed an even lower death rate percentage (50%) when they napped during the day. Of the 23,681 test participants (9,569 men and 14,112 women with ages ranging from 20 to 86 years), 792 died during the six-year period—133 from coronary artery heart disease (85 men and 48 women). Just over 50% of the test subjects were employed, while the other participants were retired or unemployed.
Other scientists have found in past scientific studies that there seems to be a direct relationship between heart problems and physical or emotional stress. In this study, sleeping during the day appears to help to relieve the physical or emotional stress that occurs in people just in living their daily lives.
The result of Trichopoulos and Naska are not without its critics. For instance, Dr. Henry Cabin, director of the Yale University-New Haven Hospital Heart Center said, “This study seems to be reasonably well-done, but maybe that ability to take a nap is a marker of a different kind of lifestyle that itself reduces risk. Maybe leading a more leisurely life is the message, rather than running home to take a nap.”
The article (“Siesta in Healthy Adults and Coronary Mortality in the General Population”) containing the conclusions of Trichopoulos and Naska appears in the Monday, February 12, 2007 issue of the Archives of Internal Medicine (http://archinte.ama-assn.org/), which is published by the American Medical Association. Also contributing to the article are Eleni Oikonomou, Antonia Trichopoulou, and Theodora Psaltopoulou.
Because of the positive health implications from the study, scientists are hoping to confirm or reject the results in future studies.