Now, modern science may be validating that Old Testament proverb --- a good laugh may actually help fend off heart attacks and strokes.
"We believe laughing is good for your health," said Michael Miller, of the University of Maryland School of Medicine in Baltimore, who led the research.
A growing body of other evidence has suggested that negative emotions, particularly depression and stress, can be harmful, making people more prone to illness, more likely to experience suffering from their ailments and less likely to recover as quickly, or at all.
So they decided to examine the ability of blood vessels to expand --- known as vasodilation.
Poor vasodilation can increase the risk of heart attacks and strokes by making the passageways prone to being blocked, cutting off vital blood flow.
The researchers asked 20 healthy men and women to watch clips of two movies --- either the violent opening battle scene in the 1998 film Saving Private Ryan or a humorous scene from a comedy, such as the 1996 Kingpin.
The researchers tested the subjects' vasodilation, before and after the movie, by constricting and releasing an artery in their arms with a blood pressure cuff and then using ultrasound to measure how the blood vessels were functioning.
The researchers discovered striking differences depending on which movie the volunteers had watched.
Blood flow was significantly reduced in 14 of the 20 volunteers who saw the stressful film.
In contrast, blood flow markedly increased in 19 of the 20 volunteers after watching the funny movie, the researchers reported this month at a meeting of the American College of Cardiology in Orlando, Fla.
Overall, blood flow decreased by about 35 percent after experiencing stress but increased 22 percent after laughter --- an improvement equivalent to that produced by a 15- to 30-minute workout.
Previous research has indicated that stress hormones may be the primary culprit by which negative emotions harm health.