Laughter really is good medicine, research shows; participants had more relaxed blood vessels after watching comedy

• Eat your veggies, exercise and have a good laugh --- and that's no joke.
• A study out Monday found for the first time that laughter relaxes blood vessels, boosting blood flow.
• Scores of studies have shown a link between a person's mental state and his or her health.
• Michael Miller, director of preventive cardiology at the University of Maryland Medical Center, theorized that laughter might promote healthier arteries by reducing mental stress, which has been shown to constrict blood vessels and reduce blood flow.
• He tested his theory on 20 volunteers, monitoring their blood pressure, cholesterol, blood-sugar levels and how their blood vessels reacted to stress.
• He then had them watch scenes from two movies.
• One, the opening scene from Steven Spielberg's realistic 1998 war movie Saving Private Ryan, was chosen to provoke stress.
• A second scene was from the 1996 Farrelly brothers comedy Kingpin.
• A total of 160 blood vessel measurements were performed before and after the laughter and mental-stress phases of the study, Miller reported at the American College of Cardiology meeting here.
• The study found that the light-hearted movie reliably relaxed the blood vessels and increased blood flow in 19 of the 20 volunteers.
• The reactions were probably prompted by the release of nitric oxide, which relaxes blood vessels much like the endorphins released during exercise.
• "When you laugh, you have less wear on your joints, and you don't have to worry about calories from chocolate," Miller said.
• "A good belly laugh a day would be a big step toward heart health."