The legislation also designates the 8th day of every month as a laughter day. But some pollies opposed the law, claiming it breached the "fundamental human right to remain straight-faced".

It’s not just Japan that is taking the health benefits of laughter seriously.

In a major new study conducted by Dr Mary Bennett at Indiana State University in the US, researchers have discovered conclusive evidence that there is a link between laughter and the ability to fight disease through the analysis of 33 healthy women.

Half of these women watched a comedy movie together, given the choice of films starring Bill Cosby, Tim Allen or Robin Williams.

The other half of the participants were made to watch a dull video on tourism.

When the films concluded, scientists took samples of the women's immune cells, known as natural killer cells, and combined them with cancer cells to see how effectively they attacked the disease.

The results revealed the participants who had found the comedy film funny enough to laugh out loud during it had significantly healthier immune systems afterwards than those who had watched the boring film on tourism.

"This could be clinically important. The use of humour to stimulate laughter could be an effective complementary therapy to decrease stress and improve natural killer cell activity in persons with viral illness or cancer,” Dr Mary Bennet said.

Humour workshops do exist and are marketed for self-healing and reducing stress, and with this study revealing that it can boost the immune system by up to 40 per cent, there’s a push for health professionals to look more seriously at humour as a complementary therapy.