Lee Berk, an associate research professor of pathology and human anatomy at Loma Linda University and a pioneer in studying the physiological effects of laughter, says regular "happy or joyful laughter" in the right doses decreases detrimental hormones and increases beneficial ones.
"That we have proven," he says. "The biological changes we see with moderate, routine exercise is very similar to the changes we see with the constant use of mirthful laughter."
Jacki Kwan leads a therapeutic humor program for residents of the Hebrew Home of Greater Washington in Rockville. At left, Katie Namrevo says she shed weight by laughing vigorously, and turned her strategy into a book.
(Lucian Perkins -- The Washington Post)
But can laughter make an ounce of difference in that midriff bulge? Berk says science has not yet proved that but it can be extrapolated. "We know the mechanisms," he says, explaining that stress causes an increase in cortisol, the hormone that causes craving for food, and laughing reduces it.
Berk figures that one day doctors will tell overweight patients to eat right, exercise regularly and get 15 minutes a day of good hearty laughter. "I'm doing it now with my patients," he says.
Robert R. Provine, professor of psychology and neuroscience at the University of Maryland, Baltimore County, thinks that would be a little premature, scientifically. In 2000 he wrote the book "Laughter: A Scientific Investigation." He says that for laughter to produce the same benefits as aerobic exercise it would require a long, sustained bout of hysterics.
"If we were treating laughter as a drug and it had to go for review before the FDA," he says, "it wouldn't pass because we really don't understand its physiological correlates and consequences."
He pauses to chuckle. "Having said that, a life with laughter is certainly more fulfilling than one without."
Of Katie Namrevo's story of shedding pounds with laughter, Provine says: "If it works for her, that's fine. . . . If you're laughing, you aren't eating."
But Namrevo thinks there's more to it than that: "I have to believe that it will work for anybody. The gift of laughter is available to everybody. It is amazing. And the side effects are all good."