By Hara Estroff Marano, published on April 5, 2005 - last reviewed on June 21, 2005
Laughter, it's said, is the best medicine. And there's lots of evidence that laughter does lots of good things for us.
It reduces pain and allows us to tolerate discomfort.
It reduces blood sugar levels, increasing glucose tolerance in diabetics and nondiabetics alike.
It improves your job performance, especially if your work depends on creativity and solving complex problems. Its role in intimate relationships is vastly underestimated and it really is the glue of good marriages. It synchronizes the brains of speaker and listener so that they are emotionally attuned.
Laughter establishes -- or restores -- a positive emotional climate and a sense of connection between two people, In fact, some researchers believe that the major function of laughter is to bring people together. And all the health benefits of laughter may simply result from the social support that laughter stimulates.
Now comes hard new evidence that laughter helps your blood vessels function better. It acts on the inner lining of blood vessels, called the endothelium, causing vessels to relax and expand, increasing blood flow. In other words, it's good for your heart and brain, two organs that require the steady flow of oxygen carried in the blood.
At this year's meeting of the American College of Cardiology, Michael Miller, M.D., of the University of Maryland reported that in a study of 20 healthy people, provoking laughter did as much good for their arteries as aerobic activity. He doesn't recommend that you laugh and not exercise. But he does advise that you try to laugh on a regular basis. The endothelium, he explains, regulates blood flow and adjusts the propensity of blood to coagulate and clot. In addition, it secretes assorted chemicals in response to wounds, infection or irritation. It also plays an important role in the development of cardiovascular disease.
"The endothelium is the first line in the development of atherosclerosis, or hardening of the arteries," said Dr. Miller. "So given the results of our study, it is conceivable that laughing may be important to maintain a healthy endothelium. And reduce the risk of cardiovascular disease."
At the very least, he adds, "laughter offsets the impact of mental stress, which is harmful to the endothelium."
The researcher can't say for sure exactly how laughter delivers its heart benefit. It could come from the vigorous movement of the diaphragm muscles as you chuckle or guffaw. Alternatively, or additionally, laughter might trigger the release in the brain of such hormones as endorphins that have an effect on arteries.
It's also possible that laughter boosts levels of nitric oxide in artery walls. Nitric oxide is known to play a role in the dilation of the endothelium. "Perhaps mental stress leads to a breakdown in nitric oxide or inhibits a stimulus to produce nitric oxide that results in vasoconstriction."
Dr. Miller offers a simple prescription that won't bankrupt you and could save your life. "Thirty minutes of exercise three times a week, and 15 minutes of laughter on a daily basis is probably good for the vascular system," he says.