By Dr. Francisco Contreras

IN A SERIES of studies at Loma Linda University in California, researcher Lee Berk discovered that watching a comedy video can strengthen your immune system in very measurable ways. Just as stressful emotions such as grief and anger can suppress your immune system, positive emotions such as laughter can have the opposite effect. When a group of people were tested after watching a comedy video, they all measured higher in immune system functions.

“Silliness is very serious stuff” said Dr. Berk, one of America’s foremost researchers on humor and health. Berk’s studies revealed statistically significant reductions in cortisol levels along with increases in antibodies that fight infection, cyotokines that regulate immune function and natural killer cells that seek out and destroy viral and tumor cells.

A good belly laugh boosts the body’s immune system and reduces hormones that cause stress. A positive state of mind helps keep healthy people well and helps the sick recover.

“There is a lot of medicinal value to laughter”, said psychologist Don Powell, founder and president of the Farmington Hills-based American Institute of Prevention Medicine. His organization incorporates laughter seminars into corporate presentations on stress management. “Laughter is a natural sensation that has positive effects both mentally and physically. It cam increase circulation, stimulate digestion and lower blood pressure. It can also reduce muscle tension,” he said.

Interest for research into the healing power of laughter was fueled by Norman Cousin’s 1979 book, Anatomy of an Illness. In it he shares how he got relief from the pain of a degenerative disease by laughing his way through humorous videos.

Dr. Berk and his partner, Dr. Stanley Tan, are pioneers in the field of laughter research called psychoneuroimmunology. Their lab tests reveal that dramatic decreases take place in us after chuckle our way through a funny video. Stress hormone levels, including epinephrine and dopamine, go way down after a good laugh. In addition, some of the changes to the immune system are still in your body the day following a good laugh.

Here’s a list of measurable changes that take place in your body after you enjoy a good laugh.

• The activity and number of natural killer cells that attack tumor cells and viruses without the help of other cells increases.
• More helper T cells that help to organize the immune system’s response are activated.
• There is an increase of the antibody immunoglobulin A, which fight respiratory tract infections.
• There is more gamma interferon, a hormone that causes the immune system to turn on. Gamma interferon fights viruses and regulates cell growth.
• There are more B cells, which cluster near lymph nodes and produce antibodies against harmful microorganisms.
• There is more “complement 3”, which helps antibodies pierce infected or dysfunctional cells.