Laughter is the best medicine

clipped from www.nature.com When stressed out, the body constricts blood vessels, elevates the production of potentially damaging stress hormones, and raises blood pressure. Short periods of stress are normal and not dangerous, but over long periods of time stress weakens the immune system and makes heart problems more likely. In 2005 researchers found that laughing lowers blood pressure, but the biochemical mechanism within the body remained unclear. Now Lee Berk at Loma Linda University in California and his colleagues have revealed part of the answer. Back in 2006, Berk and his colleagues found that merely anticipating laughter boosted the production of mood-elevating hormones called β-endorphins and the immunity-enhancing human growth hormone by 27% and 87%, respectively. This led the team to wonder whether the link between lowered blood pressure and laughter could be the result of laughter somehow interfering with the production of stress hormones.