Dr. Lee S. Berk, a preventive care specialist and psychoneuroimmunology researcher at Loma Linda University's Schools of Allied Health (SAHP) and Medicine, and director of the molecular research lab at SAHP, Loma Linda, CA, and Dr. Stanley Tan have picked up where Cousins left off. Since the 1980s, they have been studying the human body's response to mirthful laughter and have found that laughter helps optimize many of the functions of various body systems. Berk and his colleagues were the first to establish that laughter helps optimize the hormones in the endocrine system, including decreasing the levels of cortisol and epinephrine, which lead to stress reduction. They have also shown that laughter has a positive effect on modulating components of the immune system, including increased production of antibodies and activation of the body's protective cells, including T-cells and especially Natural Killer cells' killing activity of tumor cells. Their studies have shown that repetitious "mirthful laughter," which they call Laughercise©, causes the body to respond in a way similar to moderate physical exercise. Laughercise© enhances your mood, decreases stress hormones, enhances immune activity, lowers bad cholesterol and systolic blood pressure, and raises good cholesterol (HDL).
The Guardian also picked up on this.
We've pointed out before the various impacts that emotion can have on your well being. Strange to see the reports focus on appetite too.