Do the Health Benefits of Humor and Laughter Have Scientific Support?
By Paul J. Rosch, M.D.President, The American Institute of StressClinical Professor of Medicine and PsychiatryNew York Medical CollegeOriginally published in Health and Stress, the newsletter (November 2005) of The American Institute of Stress
Part of the problem in obtaining proof that laughter promotes health or prolongs life is that it is sometimes viewed as being synonymous with humor and happiness. Laughter is not the same as humor or happiness.
Laughter is the physical and physiological response to humor that frequently results in a feeling of happiness.
The only link between all of these is that happy people and those with a good sense of humor are more apt to laugh at something that is funny than their crabby counterparts.
In one study of 2,500 senior citizens that were followed for six years, those who scored high on a happiness quiz had much fewer strokes than those at the bottom of the scale.
In another study of more than 200 middle-aged healthy London civil service employees, those who reported feeling happy almost every day, whether while at work or on weekends, were significantly healthier and had lower heart rates than others who were not as consistently jolly and gleeful.
Researchers asked participants to rate their happiness at 33 times during work or leisure days during which they also monitored heart rate and blood pressure.
Saliva samples were collected eight times a day to determine concentrations of cortisol, a stress-related hormone that increases risk for heart disease and diabetes.
In addition, all were subjected to a mental stress test, following which they were asked to rate their happiness level on a scale of 1 to 5 and blood samples were obtained to measure fibrinogen, a blood clotting factor and index of inflammation associated with increased risk of coronary heart disease.
After adjusting for age, smoking, weight and other possible influences, it was found that people in the top fifth for daily happiness scores had cortisol levels 32 percent lower than those in the bottom quintile. Happiness was also linked to a lower average heart rate in men. While the majority showed some rise in fibrinogen following the mental stress test, this was far greater for the least happy group compared to those at the other end of the scale.
Surprisingly, there was no evidence of any relationship between happiness levels and age, sex, marital status or socioeconomic status. The happiest people reported feeling that way whether working or during leisure time but those who were least happy tended to report this more while they were working.
Low-Rung Employees, High Mortality Rates
These subjects were part of the large ongoing Whitehall II study designed to determine the causes and health effects of job stress in British civil service workers. The original Whitehall study that started in 1967 showed that males in the lowest clerical jobs had the highest overall mortality rate and heart disease death rate whereas top administrators had the least; there was a consistent inverse correlation between mortality and grade of employment for those in between.
The second, Whitehall II, began in 1985, and was designed to confirm and explore the reasons for this disparity. In one phase, investigators interviewed over 2,000 male civil servants aged 45-68 who had completed questionnaires detailing their medical history, job title and responsibilities, mental health, diet, smoking, alcohol use and physical exercise habits.
Various risk factors for coronary disease were measured including heart rate variability (HRV), which reflects the heart's ability to adapt to changing situations such as increased physical activity and emotional distress. As emphasized previously, low HRV, a strong predictor of sudden death and coronary events, may be the most accurate way to assess the severity of job stress.
Researchers very recently reported that a diminished HRV was more common in workers at the bottom of the corporate ladder. However, it was also associated with job stress due to a sense of little job control that was independent of civil service employment grade. One might assume that frustrated workers with little job control would be less happy than others.
HeartMath studies have also confirmed that feelings of frustration lower HRV while those of happiness and satisfaction have the opposite effect. In addition, a prior Whitehall II report on male workers showing a link between low HRV and high job stress levels may help explain why both, as well as depression, can contribute to coronary disease.
Low HRV was associated with an increase in cortisol, fibrinogen and other chemicals believed to cause insulin resistance, diabetes, hypertension and other manifestations of metabolic syndrome, a major risk factor for cardiovascular disease. This suggests that it is not that healthy people are happy but rather that they promote their health by being happy and thus have a higher HRV.
Does Laughter Really Help?
While happiness may be associated with better health or longevity, is there any proof that laughter per se provides similar benefits?
Japanese researchers suggested it might help patients with type 2 diabetes, the most common form of this disease. They showed that there was a significantly smaller spike in blood sugar after a meal when diabetics watched a popular comedy show compared to listening to a boring lecture.
In another study of patients allergic to dust mites and other common irritants, skin lesions shrank after watching Charlie Chaplin's antics in Modern Times, whereas a video containing weather information had no effect. There is abundant evidence that laughter can relieve pain, as Norman Cousins had claimed.
A five-year study that began in 2000 called Rx Laughter at UCLA's Jonsson Cancer Centre was designed to determine if laughter could lessen the pain and improve immune system function in children suffering from cancer and other chronic diseases.
It started with the help of a $75,000 grant from cable TV network Comedy Central by working with hundreds of children to determine what makes them laugh.
One of the methods used was to ask them to hold their arms in cold water as long as they could for up to three minutes. It was found that kids watching funny videos during the experiment reported significantly less pain and could also keep their arms in the cold water longer than controls not viewing the videos.
Other benefits of laughing reported by this and other groups here and abroad include:
Relaxation and reduction in muscle tension.
Lowered production of stress hormones.
Improved immune system function.
Reduction in blood pressure.
Clearing the lungs by dislodging mucous plugs.
Increasing the production of salivary immunoglobulin A, which defends against infectious organisms that enter through the respiratory tract.
Aerobic effects that increased the body's ability to utilize oxygen.
A rapid ability to disregard aches and pains or to perceive them as less severe.