Is laughter the best medicine?

“Did you hear the one about the patient whose whole left side was cut off? Good news, he’s all right now.”

Magdalena isn’t impressed. Perhaps a different joke…

“Doctor doctor, I can’t stop telling airport puns.” “I’m sorry but it’s terminal.” 

She looks annoyed. I may have misjudged this. More explanation may have been needed although jokes are never funny is you have to explain them…

Magdalena has dry eyes. She works in an airconditioned office staring at a computer screen all day. Neither she nor I can with change that. She wants a different, a medical solution.

It’s not for want of trying. Three different types of eye drop haven’t helped. The BNF is running out of options. What if the answer is laughter? 

A new paper in the BMJ examines the effect of laughter exercise on discomfort in dry eye disease. 299 patients (can you imagine how annoyed the researchers must have been not to get just one more...?), mean age 29, 74% female, were randomized to either laughter exercise or eyes drops for 8 weeks to see if the former was non-inferior to the latter.

Laughing spontaneously can be tricky, so the authors developed a repeatable vocal exercise participants would undertake for 5 minutes, 4 times a day throughout the trial. 

The laughter exercise resulted in better improvements in the ocular surface disease index (a 12 item index self-reported questionnaire assessing symptoms and quality of life effects due to dry eye, scoring from 1 – 100), demonstrating non-inferiority to standard eye drops. Tear film stability and meibomian gland function also improved. The benefits continued for at least 4 weeks after the interventions ended, something not seen with hyaluronic acid drops.

So why does this work? 

The authors acknowledge that why laughter helps dry eye disease is not entirely clear, but there is plausible physiological mechanisms. Facial and mouth muscle movements can stimulate the autonomic nervous system, including the parasympathetic NS which is the main innervator for the lacrimal and meibomian glands. Therefore it could stimulate tear secretion and in particular the lipid components essential for tear film stability. 

It may go beyond simply the eyes and the face. Dry eye symptoms correlate with mental health conditions and these can act as modulators making dry eye symptoms worse (the authors note it doesn’t work the other way around – dry eyes do not cause depression or anxiety). This may explain why eye drops may not provide the relief we would anticipate.

This made me think, is there research supporting laughter in other conditions? As it turns out there is, although the caveat is the strength of the data is not that good.

In 2023 the European Heart Journal published data showing laughter therapy cardiac rehabilitation for patients with coronary artery disease (N=26) led to improvements in oxygen levels, endothelial function and inflammatory markers. Personally I wouldn’t stop the atorvastatin but I could watch more Mock the Week.

A 2019 systematic review (which makes it sound like strong evidence but in fact acknowledges the included data was low quality) found that laugher-inducing therapies may improve depression, anxiety and stress. Funnily enough non-humorous therapies had a larger effect size than humorous ones suggesting you could still get benefit from going to a Frankie Boyle show.

How can we translate this into practice? Perhaps we can swap the droll looping movies of medical misery in our waiting rooms for Michael McIntyre. Slapstick should be avoided on health and safety grounds but having a chuckle with our patients sometimes might do us both good. 

Laughter therapy then is no joke. But it really should be.