"Keep a sense of humour. It doesn’t mean you have to tell jokes. If you can’t think of anything else, when you’re my age, take off your clothes and walk in front of a mirror. I guarantee you’ll get a laugh."-Art Linkletter

Laughter generally happens from stimuli completely unrelated to psychological state. An inward feeling of joy and happiness occurs with a joke or tickling triggered. Chemically speaking, releasing of nitrous oxide generates a feeling of euphoria which makes a person laugh. It is blessing and our ability to laugh and therefore the child laughs before he or she speaks. Laughter is a fundamental part of human and understandably common in everyday life.

Drawing upon ten years of research into this most common-yet complex and often puzzling-human phenomenon, Dr. Robert Provine, the world's leading scientific expert on laughter, investigates laughing as an evolution in his book ‘Laughter: A Scientific Investigation’, its role in social relationships, its contagiousness, its neural mechanisms and its health benefits.

Why do we laugh? Laughter has surprisingly little to do with jokes and funny stories. It is an ancient, unconsciously controlled vocal relic that co-exists with modern speech—-a social, psychological and biological act which predates humour and is shared with our primate cousins, the great apes. With startling effect, laughter reveals why humans can talk and other apes cannot and leads to the discovery of the event essential for the evolution of human speech and language. Laughter is used as a powerful, uncensored probe into human social relationships, revealing that tickle is an important form of tactile communication, that women laugh more at men than vice-versa, that speakers laugh more than their audience, and that laughter is a social glue that draws group members into the fold. Using the latest evidence, much presented for the first time, Robert Provine evaluates whether you can “laugh your way to health,” considers what laughter shows about neuropathology, and suggests how to change environments to increase laughter.

Health benefits of laughter

A link between laughter and healthy function of blood vessels was first reported in 2005 by researchers at the University of Maryland Medical Centre with the fact that laughter causes the dilatation of the inner lining of blood vessels, the endothelium, and increases blood flow. Drs. Michael Miller (University of Maryland) and William Fry (Stanford) theorize that beta-endorphin like compounds released by the hypothalamus activate receptors on the endothelial surface to release nitric oxide, thereby resulting in dilation of vessels. Other cardio protective properties of nitric oxide include reduction of inflammation and decreased platelet aggregation.

Laughter has proven beneficial effects on various other aspects of biochemistry. It has been shown to lead to reductions in stress hormones such as cortisol and epinephrine. When laughing the brain also releases endorphins that can relieve some physical pain. Laughter also boosts the number of antibody-producing cells and enhances the effectiveness of T-cells, leading to a stronger immune system. A 2000 study found that people with heart disease were 40 percent less likely to laugh and be able to recognize humour in a variety of situations, compared to people of the same age without heart disease.

Therapeutic Benefits of Laughter

Dr. Lee Berk and fellow researcher Dr. Stanley Tan of Loma Linda University in California have been studying the effects of laughter on the immune system. To date their published studies have shown that laughing lowers blood pressure, reduces stress hormones, increases muscle flexion, and boosts immune function by raising levels of infection-fighting T-cells, disease-fighting proteins called Gamma-interferon and B-cells, which produce disease-destroying antibodies. Laughter also triggers the release of endorphins, the body's natural painkillers, and produces a general sense of well-being.

Following is a summary of his research, taken from an interview published in the September/October 1996 issue of the Humour and Health Journal.

 Laughter Activates the Immune System

In Berk's study, the physiological response produced by belly laughter was opposite of what is seen in classical stress, supporting the conclusion that mirthful laughter is a eustress state -- a state that produces healthy or positive emotions.

Research results indicate that, after exposure to humour, there is a general increase in activity within the immune system, including:

• An increase in the number and activity level of natural killer cells that attack viral infected cells and some types of cancer and tumour cells.
• An increase in activated T cells (T lymphocytes). There are many T cells that await activation. Laughter appears to tell the immune system to "turn it up a notch."
• An increase in the antibody IgA (immunoglobulin A), which fights upper respiratory tract insults and infections.
• An increase in gamma interferon, which tells various components of the immune system to "turn on."
• An increase in IgB, the immunoglobulin produced in the greatest quantity in body, as well as an increase in Complement 3, which helps antibodies to pierce dysfunctional or infected cells. The increase in both substances was not only present while subjects watched a humour video; there also was a lingering effect that continued to show increased levels the next day.

 Laughter Decreases "Stress" Hormones

The results of the study also supported research indicating a general decrease in stress hormones that constrict blood vessels and suppress immune activity. These were shown to decrease in the study group exposed to humour.

For example, levels of epinephrine were lower in the group both in anticipation of humour and after exposure to humour. Epinephrine levels remained down throughout the experiment.

In addition, dopamine levels (as measured by dopac) were also decreased. Dopamine is involved in the "fight or flight response" and is associated with elevated blood pressure.

Laughing is aerobic, providing a workout for the diaphragm and increasing the body's ability to use oxygen.

Laughter brings in positive emotions that can enhance – not replace -- conventional treatments. Hence it is another tool available to help fight the disease.

Experts believe that, when used as an adjunct to conventional care, laughter can reduce pain and aid the healing process. For one thing, laughter offers a powerful distraction from pain.

In a study published in the Journal of Holistic Nursing, patients were told one-liners after surgery and before painful medication was administered. Those exposed to humour perceived less pain when compared to patients who didn't get a dose of humour as part of their therapy.

Perhaps, the biggest benefit of laughter is that it is free and has no known negative side effects.

Laughter clubs and Yoga

There are informal groups of people who get together to laugh as a form of exercise called laughter or laughing club. They are fully independent, not-for-profit, non-political, non-religious and non-competitive community-based associations of diverse people who choose to be happy. One should become part of these types of activities especially at middle or old age.

Laughter yoga [1](Hasyayoga) is a modern exercise involving prolonged voluntary laughter. This type of yoga is based on the belief that voluntary laughter provides similar physiological and psychological benefits as spontaneous laughter. It is usually done in groups, with eye contact and much playfulness between participants. Intentional laughter often turns into real and contagious laughter.

Laughter Yoga was popularized by family physician Madan Kataria who modernized and simplified the work of earlier laughter pioneers,  who taught very similar concepts starting in the 1960s. Madan Kataria wrote about his experience in his 2002 book Laugh For No Reason.

Laughter yoga is found in 53 countries. There are about 5,000 Laughter Yoga clubs worldwide, with roughly 200 of those in the United States.

Take away

1. Live, love, learn and laugh.

2. Laugh at your mistakes and you will never be exhausted.