Mirthful laughter

Doctors describe "mirthful laughter" as the equivalent of "internal jogging" because it can lower blood pressure, stress and boost the immune system much like moderate exercise.
.
A number of volunteers asked to watch just 20 minutes of comedies and stand up routines saw a dramatic drop in stress hormones, blood pressure and cholesterol.
.
That means that the "laughercise" could be a way to reduce heart disease and diabetes.
.
It is especially important to the elderly who may find it hard to perform more physical activities.
.
Dr Lee Berk, from Loma Linda University, California, who led the study, said that emotions and behaviour had a physical impact on the body.
.
He concluded "that the body’s response to repetitive laughter is similar to the effect of repetitive exercise".
.
As the old biblical wisdom states, it may indeed be true that laughter is a good medicine, he said.
.
Dr Berk, who has been studying the effects of laughter for more than two decades, said that the high you get from a giggling fit was similar to the endorphin rush from exercise.
.
He has shown how it can reduce your risk of a heart attack and diabetes and generally regulate the body's vital functions.
.
It is also an important way to de-stress after a day's work, he believes.
.
In the mid-1990s, Dr Berk found that laughter increases the number of natural killer cells in cancer patients.
.
Natural killer cells are the body's way of fighting tumours.
.
For the latest study he had 14 volunteers watch either a stressful 20 minute clip of the war film Saving Private Ryan or an extract from a comedy or stand up routine.
.
Blood samples taken afterwards showed the reduction in stress hormones and increase in immune T cells for those who watched the comedy.
.
Blood pressure testing showed it was down too with this group.
.
In 1997, Dr Berk performed experiments with diabetic heart patients.
.
One group watched a television comedy each day for one year, another did not.
.
The difference in outcomes was stunning.
.
At the end of the year, the comedy-viewing group required less blood-pressure medication.
.
Eight per cent of the comedy viewers had another heart attack, compared with 42 per cent of those who did not regularly view it.
.
An earlier study also showed that watching just half an hour of comedy a day slashes levels of stress hormones and compounds linked to heart disease.
.
Levels of compounds linked to hardening of the arteries and other cardiac problems had also dropped, while levels of 'good' cholesterol – thought to protect against heart disease – rose.
.
An earlier study by Dr Berk also showed that the mere anticipation of a good laugh can benefit health.
.
The expectation of watching a comedy video was enough to raise levels of feel-good endorphins and boost amounts of a hormone that helps our immune system fight infection.
.
The findings were presented at the Experimental Biology conference.
.
By Richard Alleyne, Science Correspondent, Times