According to a study published in the Journal of Psychosomatic Research, June 2007, laughter may increase the level of breastmilk melatonin and reduce allergic response to dust mites and latex in infants with atopic eczema.

Forty-eight infants 5-6 months of age were enrolled in the study. All of the infants had mild atopic eczema and were allergic to dust mites and latex. The infants’ mothers were divided into two groups - one group of mothers had mild atopic eczema; the second group was described as healthy.

At 2-week intervals, both groups were shown either an 87-minute humorous video (Modern Times featuring Charlie Chaplin), a non-humorous video containing weather information, or no video. Breastmilk samples were collected at 2-hour intervals after each session and the levels of melatonin measured.

Mothers who viewed the humorous video (those with atopic eczema as well as those described as healthy) had increased levels of breastmilk melatonin compared to mothers who viewed the non-humorous video or no video. In addition, allergic response to latex and dust mites was reduced in infants fed breastmilk containing higher levels of melatonin.

Melatonin is a hormone secreted by the brain that helps regulate other hormones and maintains the body’s circadian rhythm. The circadian rhythm is an internal 24-hour time-clock that affects when we fall asleep and when we wake up. Darkness stimulates the production of melatonin while light suppresses its activity. In addition to its hormonal actions, melatonin has strong antioxidant effects. Preliminary evidence suggests melatonin may help strengthen the immune system.

Maybe laughter is nothing to laugh about after all.