Recommendations for a healthy heart may one day be exercise, eat right and laugh a few times a day

Dr Michael Miller, University of Maryland

The study by doctors at the University of Maryland has found that people who fail to raise a smile in stressful or uncomfortable situations may be more likely to develop heart problems.

The authors suggest that a daily dose of laughter - by watching a funny video for instance - should be recommended by doctors alongside exercise and a low-fat diet as a way of staying healthy.

The researchers interviewed 150 people who had either suffered a heart attack or had undergone bypass surgery. Their attitudes were compared with 150 healthy people of the same age.

Embarrassing situations

Each participant was asked how they would react to a number of uncomfortable everyday situations.

These included arriving at a party to find somebody else wearing the same outfit and having a waiter spill a drink over them at a restaurant.

The researchers found that people with a history of heart problems were more likely to get angry or hostile rather than laugh or use humour to overcome the embarrassment of the situation.

People with previous heart conditions were also less likely to laugh even in positive situations.

The doctors who carried out the study believe the differences are significant. However, they are unable to explain why laughter may protect the heart against disease.

'The best medicine'

Dr Michael Miller from the University of Maryland said: "The old axiom that 'laughter is the best medicine' appears to hold true when it comes to protecting your heart.

"We don't know yet why laughing protects the heart but we know that mental stress is associated with impairment of the endothelium, the protective barrier lining our blood vessels.

We should all learn to laugh more. Perhaps it's good for our hearts

British Heart Foundation spokeswoman

"This can cause a series of inflammatory reactions that lead to fat and cholesterol build-up in the coronary arteries and ultimately to a heart attack."

Speaking at an American Heart Association Conference in New Orleans, Dr Miller suggested that doctors should perhaps consider "prescribing" laughter.

"We know that exercising, not smoking and eating foods low in saturated fat will reduce the risk of heart disease.

"Perhaps regular hearty laughter should be added to the list. We could perhaps read something humorous or watch a funny video and try to find ways to take ourselves less seriously.

"The recommendations for a healthy heart may one day be exercise, eat right and laugh a few times a day."

'Comfort foods'

A spokeswoman for the British Heart Foundation said the findings made sense.

"Depression, anxiety and social isolation can hinder patients recovery after heart attacks, so it does follow that laughter and a positive attitude could play some part in relieving stress and improving outcome for patients with heart disease.

"Perhaps people who laugh a lot are less likely to be stressed.

"Stressed, anxious or depressed people may also be more likely to smoke, be physically inactive and rely on high fat 'comfort foods' and alcohol as part of their coping strategy.

"And unfortunately these are likely to increase the risk of heart disease further. We should all learn to laugh more. Perhaps it's good for our hearts - it definitely makes you feel better."