Vigorous laughter is stimulating-increasing heart rate, blood pressure, and circulation; enhancing circulating immune substance effectiveness, pulmonary ventilation, and alertness; and exercising the skeletal muscles. Following laughter there is a brief period during which blood pressure drops and heart rate, respiratory rate, and muscle activity decrease, resulting in relaxation (Fry, 1994).
That laughter has health benefits has been claimed for centuries; however, during the past decades, several laughter- and humor-based interventions have gained widespread acceptance, and scientific studies of this phenomenon have generated considerable medical and public interest.
Most researchers will grudgingly concede that laughter is not a learned behaviour. Although it is certainly socio-culturally altered and attenuated with age, laughter is otherwise ubiquitous. It is seen in babies of three or four months and in children who are congenitally deaf and blind. We have all also felt that it can be "uncontrollable" and "infectious" - all of which suggests that laughter is a "hard-wired" reflex.
During a recent laughter fitness class at the Crafton church, Mrs. Mullen told the group of about 35 participants that laughter activates the immune system, decreases stress, relieves depression, exercises the heart and lungs and improves digestion and mental functions.
"It prevents hardening of the attitude, too," she joked.
The health and social benefits of laughter sparked the interest of Dr Madan Kataria in Mumbai, India. He believes that there are two kinds of laughter: humour, which requires certain intellectual and communication skills not available to everybody; and inner laughter, which is more emotional, childlike and accessible to all. "Children don't have a great sense of humour," he says, "they don't need jokes to laugh. They laugh because they feel like it."
Invented by a Bombay physician, Madan Kataria, in 1996, laughter yoga is predicated on the idea that "laughter for no reason" can promote spiritual well-being and health benefits, such as lowered blood pressure. The concept has given rise to laughter clubs in India and a number of other countries, including the United States, and inspired a 1999 documentary by celebrated Indian filmmaker Mira Nair (who also directed Monsoon Wedding).
"We believe laughing is good for your health," said Michael Miller of the University of Maryland School of Medicine in Baltimore, who led the research. "And we think we have evidence to show why that's the case."
A growing body of other evidence has suggested that negative emotions, particularly depression and stress, can be harmful, making people more prone to illness, more likely to experience suffering from their ailments and less likely to recover as quickly, or at all.
Hundreds of studies show how laughter affects us physically: Laughter enriches the blood with oxygen, reduces stress hormones, improves the immune system, boosts endorphins (the feel-good hormones), and lowers blood pressure. It decreases depression, anxiety and psychosomatic disorders and internally massages the digestive tract, improving digestion. It even burns calories. But more important, it feels so good to laugh. And we don't need studies to tell us that.
Cutting to the chase, clinical researchers have shown several health benefits of laughter throughout our body.
Starting with the cardiovascular system, blood flow responds positively to laughter and joy. Good humored people generally have blood vessels that contract and expand easily; they are elastic.
Laughter helps keep Pereira’s memory sharp, too. Since she began laughter therapy, she says she’s been more alert and interacts better with her friends at the senior center.