There may be something to siestas after all. Office workers feeling a bit drowsy during the day may feel better about themselves knowing that midday napping seems to reduce fatal heart problems by about one third among men and women, according to new research.

The study, released Monday, followed more than 20,000 individuals over an average of 6.3 years. Initially, all individuals were healthy at the start. The study also controlled details for risk factors such as diet and physical activity.

The study was carried out by the Harvard School of Public Health and the University of Athens Medical School in Greece.

Siestas, which are common in the Mediterranean region and some Latin American countries, tend to have people with low mortality rates of coronary heart disease, the study said.

The study found that people who took an average of three naps per week, for 30 minutes each had 37 percent lower coronary mortality than those who did not. Occasional nappers found a 12 percent reduction in coronary mortality, however this was not considered statistically significant by the researchers.

"The apparent protective effect of siestas was particularly strong among working men and weaker among those not working, mainly retirees,' the HSPH said. The difference among women could not be tracked clearly.

The authors of the study believe that siestas could act as stress-releasing process.

"The fact that the association was more evident among working men compared to retirees apparently reflects the different stress levels these subgroups have to cope with,' the HSPH said.

The study, titled, "Siestas of Health Adults and Coronary Mortality in the General Population,' appears in the February 12 issue of The Archives of Internal Medicine.

The authors are Androniki Naska, Eleni Oikonomou, Antonia Trichopoulou, Theodora Psaltopoulou, Dimitrios Trichopoulos.