A laugh really is best medicine

Watching a comedy could be as effective as going for a run in boosting health.

Researchers have found that a spell of hearty laughter causes the tissue that forms the inner lining of the blood vessels, the endothelium, to dilate, increasing blood flow in the same way as a bout of aerobic exercise.

The finding adds to evidence that a laugh a day may help keep a heart attack away. Michael Miller, of the University of Maryland, who has studied the healing power of laughter for a decade, said: "The old saying that laughter is the best medicine definitely appears to be true when it comes to protecting your heart."

For his latest study, twenty volunteers watched 15-minute segments of sad movies, such as the opening of Saving Private Ryan, and funny ones such as There's Something about Mary.

Researchers using ultrasound monitored the blood flow in the brachial artery in the arm of each volunteer. They found blood flow was reduced in 14 of the 20 participants after watching distressing movie clips and increased in 19 out of the 20 participants after watching clips that made them laugh.

The difference in flow between happy and sad responses exceeded 50 per cent. The findings are published in the journal Heart.

Dr Miller said: "The magnitude of change we saw in the endothelium is similar to the benefit we might see with aerobic activity, but without the aches, pains and muscle tension associated with exercise."

"We don't recommend that you laugh and don't exercise but we do recommend that you try to laugh on a regular basis. Thirty minutes of exercise three times a week and 15 minutes of laughter on a daily basis is probably good for the cardiovascular system."

- INDEPENDENT