A hearty laugh a day may keep the doctor away, say the findings
of a unique study. Whereas previous studies have examined how negative
emotions can adversely affect our health, this study took a new
spin--they measured the affect of watching a funny movie on the
ability of heart blood vessels to expand. And they found some surprising
results--laughing increased blood flow as much as a 15- to 30-minute
workout.

The ability of blood vessels to expand is known as vasodilation.
Poor vasodilation means that passageways may be blocked and blood
flow may be cut off. The result is an increased risk of heart attacks
and strokes.

In the study, 20 healthy men and women watched clips of two movies--a
violent battle scene from "Saving Private Ryan" or a humorous
scene from a comedy such as "Kingpin." Each participant's
vasodilation was measured prior to the movie and again afterward.

The results were "dramatic." Of the 20 participants who
saw the stressful film, 14 had significantly reduced blood flow.
However, after watching the funny film, 19 of the 20 volunteers
had significantly increased blood flow. Specifically:

• 
  Blood flow decreased by about 35 percent
  after experiencing stress
  


• 
  Blood flow increased by 22 percent
  after laughing, which is equivalent to what happens after a
  15- to 30-minute workout
  

Past studies have found that stress hormones like adrenalin and
cortisol, which is released when a person is stressed, may harm
the body by suppressing the immune system and constricting blood
vessels. On the other hand, the researchers believe laughing causes
the body to release beneficial chemicals called endorphins, which
may counteract the effects of stress hormones and cause blood vessels
to dilate.

In a similar manner, laughing may also boost the immune system
and reduce inflammation, which is thought to increase the risk of
various health problems.

The researchers say they have a long way to go before their hypothesis
will be proven, but they point out that there's no downside to laughing
and they have no problem recommending it to their patients.

Washington
Post March 14, 2005