Researchers at the Harvard School of Public Health who conducted a study on Greek men and women found that taking a daily midday nap may reduce the risk of dying from heart disease by more than 30%. Siestas are common in Mediterranean countries and several Latin American nations, where the rate of dying from heart disease is comparatively low. Researchers believe that naps are effective at promoting heart health because they relieve stress.
http://www.iht.com/articles/2007/02/13/opinion/web.0213nap.php
