Study Shows Laughter Reducing Heart Disease Risk

Study Shows Laughter Reducing Heart Disease Risk

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laughingtravIn March 2005, Researchers at the University of Maryland School of Medicine in Baltimore presented results for the first time that showed laughter is linked to healthy function of blood vessels. The magnitude of benefit observed was similar to that produced by aerobic activity.

"Given the results of our study, it is conceivable that laughing may be important to reduce the risk of cardiovascular disease," says principal investigator Michael Miller, M.D., director of preventive cardiology at the University of Maryland Medical Center and associate professor of medicine at the University of Maryland School of Medicine. "At the very least, laughter offsets the impact of mental stress." . . .
"We do recommend that you try to laugh on a regular basis," says Dr. Miller. "Thirty minutes of exercise three times a week, and 15 minutes of laughter on a daily basis is probably good for the vascular system."

Volunteers were shown funny and disturbing movies to test the effect of emotions on blood vessels. The study included a group of 20 non-smoking, healthy volunteers, equally divided between men and women, whose average age was 33. The participants had normal blood pressure, cholesterol and blood glucose levels. Each volunteer was shown part of two movies at the extreme ends of the emotional spectrum. The opening scene of "Saving Private Ryan" (DreamWorks, 1998), or a segment of a movie that would cause laughter, such as "King Pin" (MGM, 1996).


There were no differences in the baseline measurements of blood vessel dilation, but there were striking contrasts after the movies were seen. Brachial artery flow was reduced in 14 of the 20 volunteers following the movie clips that caused mental stress. In contrast, beneficial blood vessel relaxation was increased in 19 of the 20 volunteers after they watched the movie segments that generated laughter. Overall, average blood flow increased 22 percent during laughter, and decreased 35 percent during mental stress.

Dr. Miller says this study was not able to determine the source of laughter’s benefit, and he wonders, "Does it come from the movement of the diaphragm muscles as you chuckle or guffaw, or does it come from a chemical release triggered by laughter, such as endorphins?"

The current study builds on earlier research Dr. Miller conducted on the potential benefits of laughter, reported in 2000, which suggested that laughter may be good for the heart. In that study, answers to questionnaires helped determine whether people were prone to laughter and ascertain their levels of hostility and anger. Three hundred volunteers participated in the study. Half of them had suffered a heart attack or had undergone coronary artery bypass surgery; the other half did not have heart disease. People with heart disease responded with less humor to everyday life situations than those with a normal cardiovascular system.

Dr. Miller says certain factors in the earlier study may have affected the results. For example, he says it may be that people who have already had a coronary event are not as laughter-prone as those who do not have heart disease.

He says the current study sought to eliminate that uncertainty by using volunteers whose cardiovascular system was healthy. The results of the brachial artery blood flow measurements, which are precise and objective, appear to make the connection between laughter and cardiovascular health even stronger, according to Dr. Miller. (UMM News)