Friday, May 15, 2015

Laughter is the best medicine

Benefits of laughter include reduced anger, anxiety, depression, and stress; reduced tension (psychological and cardiovascular); increased pain threshold; reduced risk of myocardial infarction (presumably requiring hearty laughter); improved lung function; increased energy expenditure; and reduced blood glucose concentration. However, laughter is no joke—dangers include syncope, cardiac and oesophageal rupture, and protrusion of abdominal hernias (from side splitting laughter or laughing fit to burst), asthma attacks, interlobular emphysema, cataplexy, headaches, jaw dislocation, and stress incontinence (from laughing like a drain). Infectious laughter can disseminate real infection, which is potentially preventable by laughing up your sleeve.

Ferner RE, Aronson JK. Laughter and MIRTH (Methodical Investigation of
Risibility, Therapeutic and Harmful): narrative synthesis. BMJ. 2013 Dec 12;347


  1. Martin RA. Humor, laughter, and physical health: methodological issues and
    research findings. Psychol Bull. 2001 Jul;127(4):504-19.


    All published research examining effects of humor and laughter on physical health is reviewed. Potential causal mechanisms and methodological issues are discussed. Laboratory experiments have shown some effects of exposure to comedy on several components of immunity, although the findings are inconsistent and most of the studies have methodological problems. There is also some evidence of analgesic effects of exposure to comedy, although similar findings are obtained with negative emotions. Few significant correlations have been found between trait measures of humor and immunity, pain tolerance, or self-reported illness symptoms. There is also little evidence of stress-moderating effects of humor on physical health variables and no evidence of increased longevity with greater humor. More rigorous and theoretically informed research is needed before firm conclusions can be drawn about possible health benefits of humor and laughter.

  2. Liangas G, Morton JR, Henry RL. Mirth-triggered asthma: is laughter really the best medicine? Pediatr Pulmonol. 2003 Aug;36(2):107-12.


    Mirthful emotions such as laughter and excitement are unrecognized but perhaps important triggers of asthma. Our study aimed to explore the prevalence, mechanisms, and associations of mirth-triggered asthma (MTA) in children. Our MTA prevalence questionnaire was given to 285 children who presented to the Emergency Department of Sydney Children's Hospital (SCH) with an acute episode of asthma. Our MTA profile questionnaire study was a cross-sectional study of 541 children with asthma. The parents completed a questionnaire regarding their child's asthma. In our laughter diary study, diary cards were given to the parents of 21 children with asthma. The diary required details regarding the mirthful stimulus, symptoms of asthma, and recording of peak expiratory flow (PEF) measurements. Of the selected cohort, 31.9% had mirth-triggered asthma. In the cross-sectional study, mirth-triggered asthma was more common: with increasing age (P = 0.02); in those who in the last 3 months had taken more doses of salbutamol (P = 0.005), and who had more wheeze, nocturnal symptoms, and early morning symptoms (P < 0.0005); and in those who reported exercise-induced asthma (P < 0.0005). Laughter was more commonly reported as a trigger than excitement; cough was the most prominent symptom; and symptoms mostly occurred within 2 min of the mirthful stimulus. In the laughter diary study, 59 of 130 recorded events described symptoms of asthma. Mirth while watching a film led to PEF of 73% of baseline, compared with 81% for mirth with exertional play, and 95% for mirth with nonexertional play (P = 0.01). Mirth-triggered asthma is common, and is an indicator of suboptimal asthma control.