Laughter Affects Appetite Much Like a Workout Does
Study Finds Repetitive Laughter Has an Impact on Appetite Hormones
April 27, 2010 (Anaheim, Calif.) -- A hearty laugh and a moderate workout may have more in common
than anyone thought.
Both affect the appetite hormones in much the same way, says Lee Berk, DrPH,
MPH, director of the molecular research laboratory at Loma Linda University in
Loma Linda, Calif., and a longtime researcher on the benefits of laughter.
''The parallel between moderate exercise and mirthful laughter is uncanny,"
Berk tells WebMD.
But he's clear from the start: "You can't increase leg muscle strength by
sitting and laughing."
But he does think laughter, already linked with reducing stress and heart disease risk, as well as
other benefits, may help improve appetite in those who have lost theirs due to
disability or age. And it may improve wellness for the rest of us.
Laughter, Workout Link
In previous research, Berk has found that ''mirthful laughter'' reduces the
stress hormones known as cortisol and catecholamines, much the same way that
moderate physical exercise does.
It’s also been found to enhance immune system functioning and may lower cholesterol and blood pressure.
In the new study, Berk evaluated the effects of a good belly laugh on two
hormones that regulate appetite: leptin and ghrelin.
"When leptin goes down, it increases appetite," Berk says. "When ghrelin
goes up, it increases appetite.''
That is what typically happens after moderate exercise, he says.
To test the effects of exercise on these hormones, he showed 14 healthy
volunteers, average age 21, 20-minute segments of two different videos.
One was humorous, and the participants selected one depending on their
preference. Choices included videos with Bill Cosby, Jeff Foxworthy, Will
Ferrell, and others.
He also showed them a video meant to be stressful to watch, the 1998 movie
Saving Private Ryan, a graphic World War II movie.
The participants watched the videos in random order. They gave blood to
assess their leptin and ghrelin levels a week before the study, immediately
before viewing, and immediately after viewing the videos. The hormones were
measured well before viewing, Berk says, to rule out the well-known
Laughter, Workout Study Results
After watching the funny videos, participants had a decrease in leptin of
about 15%, Berk found. After watching the war movie, there were no significant
changes in the hormone.
They had an increase in ghrelin after viewing the humorous video of about
9%, he found, but no change after the war movie.
The results don't mean that laughter increased appetite, he says, but
rather that the body's response to repetitive laughter is similar to that of
Laughter, Workout Study: Implications
Berk hopes the research may help elderly people who have lost their
appetite, whether due to depression, illness, or lack of
''The second application is for wellness," he says. Laugh while you work
out, he suggests, and you may just be tuning up your appetite hormones, keeping
them in balance, as well as improving your cardiovascular fitness.
The research, he says, may help those who have difficulty getting in
physical activity, such as those who are physically handicapped or elderly.