"Laughter in and of itself cannot cure cancer nor prevent cancer, but laughter as part of the full range of positive emotions including hope, love, faith, strong will to live, determination and purpose, can be a significant and indispensable aspect of the total fight for recovery."  (Harold H. Benjamin, PhD founder of The Wellness Community) 

Here is what we know so far about humor and laughter's effect on our bodies:

Lee Berk, associate professor at Loma Linda University School of Medicine, has produced carefully controlled studies showing that the experience of laughter lowers serum cortisol levels, increases the amount of activated T lymphocytes, increases the number and activity of natural killer cells, and increases the number of T cells that have helper/ suppresser receptors. In short, laughter stimulates the immune system, off-setting the immunosuppressive effects of stress. This research is part of the rapidly expanding field of Psychoneuroimmunology which defines the communication links and relationships between our emotional experience and our immune response as mediated by the neurological system.

We know that, during stress, the adrenal gland releases corticosteroids (quickly converted to cortisol in the blood stream) and that elevated levels of cortisol has an immunosuppressive effect. Berk's research demonstrates that laughter can lower cortisol levels and thereby protect our immune system.

Laughter stimulates an increase in the number and activity of natural killer cells (NK) NK cells are a type of immune cell that attacks viral or cancerous cells and do not need sensitization to be lethal. They are always ready to recognize and attack an aberrant or infected cell. This becomes very important in the prevention of cancer. Cells within our bodies are constantly changing and mutating to produce potential carcinogenic cells. An intact immune system can function appropriately by mobilizing these natural killer cells to destroy abnormal cells.

Receptor sites are important as a communication link between the brain and the immune system. Emotions can trigger the release of neurotransmitters from neurons in the brain. These chemicals then enter the blood stream and "plug into" receptor sites on the surface of immune cells. When this occurs, that cell's metabolic activity can be altered in either a positive or negative direction. Many cells within the body have different receptor sites on their surface; of particular interest in this research are those on the immune cells.

Other researchers have supported these findings. Locke at Harvard, showed that the activity of natural killer cells is decreased during periods of increased life change which were accompanied by severe emotional disturbance; whereas subjects with similar patterns of life change and less emotional disturbances had more normal levels of NK cell activity. At the VA Medical Center in San Diego in 1987, Irwin noted that NK cell activity decreased during depressive reaction to life changes. At the Ohio State University School of Medicine, Janice and Ronald Glaser studied the cellular immunity response patterns of medical students before examinations. Their work showed a reduction in the number of helper T cells and a lowered activity of the NK cell during the highly anxious moments just before the examination.

Salivary immunoglobulin A is our first-line defense against the entry of infectious organisms through the respiratory tract. At SUNY, Stone revealed that salivary immunoglobulin A response level was lower on days of negative mood and higher on days with positive mood. This finding was quickly confirmed by two other researchers. Dillon, working at Western New England College; found subjects showed an increased concentration of salivary IgA after viewing a humorous video; while Lefcourt, from University of Waterloo in Onterio, showed that subjects who tested strong for appreciation and utilization of humor had an even stronger elevation of salivary IgA after viewing a humorous video.

All this research, done in the last ten years, helps us to better understand the mind-body connection. The emotions and moods we experience directly effect our immune system. A sense of humor allows us to perceive and appreciate the incongruities of life and provides moments of joy and delight. These positive emotions can create neurochemical changes that will buffer the immunosuppressive effects of stress.

Dr. Berk describes his research results: "Essentially, we found that mirthful laughter serves to modulate specific immune system components. By modulate, we mean that chemicals released during the emotional experience of mirth can connect to receptors on the surface of the immune cells. This connection stimulates a change in the molecular machinery inside the cell. Specific molecules known as immunoregulators are like plugs that fit into receptors and subsequently increase or decrease the immune cell activity. One metaphor for modulation of immune activity is the conductor of an orchestra. Although the conductor does not actually play an instrument, he influences the tempo, harmony and volume of the music produced by the orchestra. Mirthful laughter would be like the conductor who enhances sonic integration and brings out melodious harmony. Whereas distressful emotions would be like the conductor who brings out harsh, disharmonious sounds. Emotions, like a conductor, modulates the activity and effectiveness of the immune cells although it does not directly protect the body from insult or infection."