Good laugh may protect your heart

NEW ORLEANS - Laughter may indeed be the best medicine, researchers say.

A recent study shows that people who say they laugh more are less likely to have heart disease.

"The old axiom that laughter is the best medicine appears to hold true when it comes to protecting your heart," said Dr Michael Miller, director of the centre for preventive cardiology at the University of Maryland in Baltimore.

"This is the first study to demonstrate a link between laughter and heart disease."

Dr Miller and colleagues told a meeting of the American Heart Association that they believed laughter might release chemicals that relax the blood vessels. "It's not just going 'ha, ha, ha'," Dr Miller said. "It's having a good, hearty laugh."

For their study, they interviewed 150 patients who had either suffered heart attacks or had undergone procedures such as angioplasty to clear clogged arteries.

They compared their responses with those of 150 people the same age who did not have heart disease.

The questions came off standard tests used to measure humour in day-to-day situations, such as getting to a party to find someone else wearing the same outfit.

"If you were woken up in the middle of the night by a good friend who had been out of town and whom you hadn't seen for a while, how would you respond?" Dr Miller asked.

"We found that individuals who had heart disease had a 40 to 45 per cent reduced likelihood of laughing in response to those social situations."

He hopes laughter may one day be used for therapy.

"We don't know yet if forcing yourself to laugh when you're angry is beneficial, but there may be effective, practical ways for people to lessen their discomfort or hostility to improve their humour response and increase the amount of laughter in their lives," Dr Miller said.

"There is no reason we can't learn to regulate our laughing muscles, like all the other exercises we do."

Dr Miller said his team was now looking to see if the act of laughing released chemicals that affected the blood vessels, perhaps like nitric oxide, known to dilate blood vessels.

The chemical, related to the nitrous oxide used to relax dental patients, is already targeted by some heart drugs.

Dr Miller said many studies had shown that feelings of anger and hostility caused the cells lining blood vessels to release chemicals that made them constrict.

A second study, released in the Journal of the American College of Cardiology, tended to confirm this.

Dr Peter Angerer, of the Medizinische Klinik der Universitat Muenchen-Innenstadt in Munich, Germany, found that angry, lonely people developed heart disease.

"We demonstrated that low perceived social support and, to a lesser extent, high outwardly expressed anger were associated with accelerated progression [of heart disease] within two years of follow-up," Dr Angerer said.

They used angiography to examine 150 heart patients' arteries and asked them questions designed to measure social support, anger expression and hostility. Two years later, the patients had angiography again to see whether their atherosclerosis - clogged, hardened arteries - had worsened.

Patients who had high scores on anger expression and low scores on social support were much more likely to have even worse atherosclerosis than before, Dr Angerer's team reported.

- REUTERS