January 20, 2006
Laughter Really May Be Good Medicine
By Amy Norton
NEW YORK -- Sitting through a funny movie seems to be as good for your heart as running through the park, a small study suggests.
In an experiment with 20 healthy young adults, researchers found that participants' blood flow improved when they watched a movie that made them laugh. In fact, the circulation boost was similar to what's been seen with aerobic exercise, according to findings published in the February issue of the medical journal Heart.
However, that doesn't mean laughing should take the place of running, Dr. Michael Miller, the study's lead author, told Reuters Health. Instead, an "optimal scenario" might be to watch a funny movie while jogging on a treadmill, said Miller, who is with the University of Maryland Medical Center in Baltimore.
Exactly why laughing might give a jolt to the circulation isn't clear. It's possible that it counters the effects that stress hormones can have on blood vessel function, Miller and his colleagues speculate. In addition, laughter may spur the body's production of nitric oxide, a chemical that helps dilate blood vessels.
The study involved healthy men and women who submitted to several non-invasive measurements of blood flow in the arm's brachial artery. Dilation in this artery is a good indicator of blood flow to and from the heart.
The measurements were taken before and after participants watched clips from a comedy film, such as "Something About Mary," and from a distressing film, like "Saving Private Ryan."
On average, the researchers found, participants' blood vessel dilation was more than 50 percent better after the comedy than after the depressing film.
A number of studies have linked negative emotions, such as major depression and chronic hostility, to poorer heart health. Researchers have speculated that persistent elevations in stress hormones may be involved. But far less is known about the cardiovascular effects of positive emotions, according to Miller.
He said he hopes these findings will spark more research into how positive feelings influence heart health.
SOURCE: Heart, February 2006.