In 1979, a groundbreaking book by Dr. Norman Cousins was published, Anatomy of an Illness. In this book, Dr. Cousins described how watching hilarious Marx Brother movies helped him recover from the painful disease, ankylosing spondylitis. He was so thrilled about the effects of laughter and humor that he spent the last 10 years of his life doing clinical research at UCLA Medical School and established the Humor Task Force. Dr. Cousins’ work eventually led to the field of psychoneuroimmunology (PNI), a new science hanging on to the edge of medical acceptance. PNI is now a field of medical research that attributes aspects of both the psyche and the nervous system as having a measurable influence on the body’s immune system.

The impact of Cousins’ work has evolved (over the past 25 years) to the point where research documenting the power of our emotions on the physical body is acceptable. Fast forward to the Scientific Session of the American College of Cardiology on March 7, 2005 in Orlando, Florida. At this session, the University of Maryland Medical Center presented results of a study proving that positive emotion has a positive effect on cardiovascular health. Their results were published online at the University of Maryland School of Medicine’s website.

We now know that laughter and positive emotion help blood vessels function better. The inner lining of blood vessels (the endothelium) has a powerful effect on blood vessel tone, regulates blood flow and, in general, plays an important role in cardiovascular disease development. When the endothelium dilates, blood flow is increased – and when it constricts, blood flow is decreased. The principal investigator of this study, Michael Miller, M.D. is the director of preventive cardiology at the University of Maryland Medical Center and associate professor of medicine at the University of Maryland School of Medicine. Dr. Miller claims that “the endothelium is the first line in the development of atherosclerosis or hardening of the arteries, so, given the results of our study, it is conceivable that laughing may be important to maintain a healthy endothelium, and reduce the risk of cardiovascular disease.”

This study measured the cardiovascular effects from viewing 30 minute segments of emotion provoking film. They used clips from a movie that caused mental stress, “Saving Private Ryan” (DreamWorks, 1998) and clips from a movie that was humorous, “King Pin” (MGM, 1996). Blood vessel reactivity was measured before and after watching the movies. The findings were that blood vessels dilated following watching a funny movie (increasing in diameter 22%), and that blood vessels constricted following watching a stressful movie (decreasing in diameter 35%). The subjects of this study were non-smokers with healthy cardiovascular systems. The good health of the volunteers removes study bias, lending itself to be respected, reproducible and to contain reliable conclusions.

These results go a long way in supporting Cousins’ earlier findings, and in confirming that laughter does a body good. “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,” says Dr. Miller. “We don’t recommend that you laugh and not 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 vascular system.”

Perhaps we’ll see a new movement in healthcare, taking the phrase “laughter is the best medicine” to a clinical level. Some people have been quick to catch on, as laughter clinics spring up in hospitals and laughter clubs make a nationwide debut. Most bodyworkers already know that positive emotion and relaxation have far reaching holistic health benefits – except now there is scientific data to back it up.