A level psychology students will be aware that this is not a very scientific approach; nevertheless it has spurred more rigorous research into what is now known as lifestyle medicine.
Dr Lee Berk's research in the 1980s showed that anticipation of "mirthful laughter" increases the levels of beta-endorphins (which make you feel good) and human growth hormone, which has been shown to have a number of positive effects on the body, including improved functioning of the immune system (Powers, 2005).
Another study by Berk found that the stress hormones adrenaline and cortisol, as well as a metabolite of dopamine were reduced by the anticipation of laughter.
What these studies did not investigate was whether laughter has a beneficial effect on people with actual illnesses. Dr Berk has, however, recently teamed up with Stanley Tan, MD, PhD an endocrinologist and diabetes specialist at Oak Crest Health Research Institute, Loma Linda, CA, to examine the effect of "mirthful laughter" on individuals with diabetes.
Diabetes is a metabolic Syndrome characterized by the risk of heart attack, blindness and other neurological, immune and blood vessel complications.
The new research followed 20 high risk diabetic patients who received standard medical treatments for diabetes. The patients were divided into two groups, a laughter group who watched 30 minutes per day of self selected comedy and a control group who were not instructed to watch comedy.
The results showed that compared with the control group, the laughter group had increased levels of HDL (good) cholesterol and less inflammation. This means that that laughter may lower the risk of cardiovascular disease in these patients.
"The best clinicians understand that there is an intrinsic physiological intervention brought about by positive emotions such as mirthful laughter, optimism and hope." claimed Dr Berk.
"Lifestyle choices have a significant impact on health and disease and these are choices which we and the patient exercise control relative to prevention and treatment."
The results will be presented at the 122nd Annual Meeting of the American Physiological Society (APS), which is part of the Experimental Biology 2009 scientific conference. The meeting will be held April 18-22, 2009 in New Orleans.
