Laughter is not only an effective stress-reliever, but can be heart-healthy, according to research presented at the American College of Sports Medicine's 56th Annual Meeting in Seattle. Two separate studies examined the role of a good laugh as it relates to health.

One of the studies took an inverted approach to previous research on the harmful cardiovascular tolls of stress and negative mood. A small group of healthy adults were instructed to watch either a comedy or documentary film, and were monitored for carotid artery activity during the films.

Subjects who watched the comedy benefited from improved "arterial compliance," the amount of blood that moves through the arteries at a given time. Conversely, decreased arterial compliance is often associated with high blood pressure and heart disease.

"Arterial compliance was improved for a full 24 hours after subjects watched a funny movie," said lead researcher Jun Sugawara. "Laughing is likely not the complete solution to a healthy heart, but it appears to contribute to positive effects."

A second study found similar results in vascular function. When another group watched either a comedy or a somber documentary, blood vessels became more dilated during the comedy. Constricted blood vessels often lead to high blood pressure. Like the first study, favorable effects on vascular function were sustained for 24 hours.

"Not only did comedies improve vascular dilation, but watching a documentary about a depressing subject was actually harmful to the blood vessels," said Takashi Tarumi, lead researcher on the study. "These documentaries constricted blood vessels by about 18 percent."

In addition to laughter, a significant body of evidence exists that shows exercise as a preventive mechanism against both cardiovascular disease and high blood pressure. ACSM's Exercise is Medicine program promotes these curative and protective benefits, and encourages all patients to talk with their doctor or health care provider about their physical activity programs.

American College of Sports Medicine