The old adage that “laughter is the best medicine” may contain an element of truth when it comes to heart health. A study has demonstrated that having a chuckle causes the tissue inside the heart to expand – and increases oxygen flow around the body. Patients with coronary artery disease who engaged in a course of laughter therapy had reduced inflammation and better health, the research found. “Our study found that laughter therapy increased the functional capacity of the cardiovascular system,” said the lead author, Prof Marco Saffi, of the Hospital de Clínicas de Porto Alegre in Brazil. The findings were presented at the annual meeting of the European Society of Cardiology in Amsterdam, the world’s largest heart conference. In the trial, scientists carried out a first-of-its-kind study to examine if laughter therapy could improve symptoms of patients with heart disease. It involved 26 adults with an average age of 64, all diagnosed with coronary artery disease, caused by plaque buildup in the walls of the arteries that supply blood to the heart. Over three months, half were asked to watch two different hour-long comedy programmes each week, including popular sitcoms. The other half watched two different serious documentaries, about topics such as politics or the Amazon rainforest. At the end of the 12-week study period, the comedy group improved by 10% in a test measuring how much oxygen their heart could pump around the body. The group also improved in a second measure that tested how well arteries can expand. They also had blood tests to measure several inflammatory biomarkers, which indicate how much plaque has built up in the blood vessels, and whether people are at risk of heart attack or stroke. The results showed that these inflammatory markers had significantly reduced compared with the control group. “When patients with coronary artery disease arrive at hospital, they have a lot of inflammatory biomarkers,” said Saffi. “Inflammation is a huge part of the process of atherosclerosis, when plaque builds up in the arteries. “This study found that laughter therapy is a good intervention that could help reduce that inflammation and decrease the risk of heart attack and stroke. “Laughter therapy could be implemented in institutions and health systems like the NHS for patients at risk of heart problems. “It does not have to be TV programmes – people with heart disease could be invited to comedy evenings, or encouraged to enjoy fun evenings with friends and family. People should try do do things that make them laugh at least twice a week.” In future, Saffi suggested, laughter therapy could help reduce dependence on medication. While scientists are still advancing research into why a good giggle might be good for the heart, they now have a firm understanding. “Laughter helps the heart because it releases endorphins, which reduce inflammation and helps the heart and blood vessels relax,” Saffi said. “It also reduces the levels of stress hormones, which place strain on the heart. “Laughing helps people feel happier overall, and we know when people are happier they are better at adhering to medication.” Prof James Leiper, associate medical director at the British Heart Foundation, who was not involved in the research, said: “While this study reveals the interesting possibility that laughter could in fact be a therapy for coronary artery disease, this small trial will need to be replicated to get a better understanding of how laughter therapy may be helping these patients. “It’s encouraging to see that something so simple and widespread could benefit our health but more research is needed to determine whether laughter alone led to the improvements seen, and how long the effects could last.”