The healing power of humour?
By Sarah Mayes

OTTAWA — Laughter may not be the best medicine, but humour may be. That’s the take-home message of a recent study examining the last 45 years of health-related humour research.

Dr. Rod Martin, a researcher at the University of Western Ontario, reviewed all the research related to humour and health, trying to separate fact from fiction. He published his findings in the International Journal of Humor Research last year. He says as it stands now, there isn’t much solid evidence for some of the health claims about humour.

“Basically I would say that the idea that humour might be beneficial [to health] is not a bad idea,” he says.

“There is research suggesting that…But the problem is that the research so far has not been done very well.”

Dr. Martin says the biggest problem with humour research to date is that the experiments haven’t been adequately controlled. The trouble is, humour is subjective. So researchers need to ensure that their experimental conditions are actually funny.

Martin says a common experimental design is one where subjects watch a funny film, then are subjected to pain. He says this should always be followed up with a questionnaire asking subjects to give the movie a funniness rating – something that researchers don’t always do.

Rod Martin is a professor of psychology at the University of Western Ontario.

Researchers can also use documentary or scary film conditions in their experiments, to make sure any observed effects aren't due to distraction or other emotions.

Despite poor scientific evidence, the claims about humour abound: it’s purported to “boost” the immune system, provide a natural analgesic effect, and even promote a longer, healthier life.

And you only have to type the words “humour” and “health” into an Internet search engine, and up pop a slew of related products and services: a website for the Canadian Therapeutic Humour Association, promos for the popular film Patch Adams, and even a software that allows doctors to give their patients personalized humour prescriptions. You can even become trained as a “laughter leader.”

Self-medicating on comedy

John Gupta is one. The Montrealer has taught an obscure brand of yoga, known as “laughter yoga”, to over a thousand people in Canada and US. Some of his students have been members of Gilda’s Club, a support center for people living with cancer.

“It’s simulated laughter. It’s laughter without jokes, and that’s the whole idea,” he says.

Gupta says laughter yoga exercises can be quite simple.

“It could just be greeting, like the Indian-style greeting: you hold your palms together, you make eye contact with people and then you go around and you just laugh,” he says.

“And everybody just starts getting into the action, everybody’s laughing…You feel the energy. When people are together and laughing together, it creates such an energy, it’s unbelievable.”

The idea that humour could have a beneficial effect on health has been around for centuries, but it’s also had its modern champions. Norman Cousins was among them. Cousins was the editor of prominent US literary magazine, The Saturday Review. In 1964 he was diagnosed with a progressive, debilitating inflammatory disorder that put him in constant pain. He was given about six months to live.

As the story goes, Cousins began self-medicating with doses of comedy: he watched repeated episodes of Candid Camera, and Marx Brothers movies. Cousins claimed that 10 minutes of hearty laughter would provide two hours of pain-free sleep. He recovered from his condition, and documented his experience in his book, Anatomy of an Illness (1979).

Laugh your pain away?

Dr. Martin says Cousins may have been on to something. However, Martin says the humour-longevity claim has largely been disproved, funny people have been shown to be no healthier than the rest of the population, and the jury’s still out on any beneficial effects that humour may have on the immune system. But he says studies into the effects of humour on pain are quite promising.

"Researchers have done some pretty well-controlled studies, and they all pretty consistently indicate that when people are exposed to humour they can tolerate more pain,” he says.

Dr. Willibald Ruch, a researcher at the University of Zurich, published one such study last year, in the International Journal of Humor Research.

Willibald Ruch is a researcher at the University of Zurich.

"We wanted to look at [the analgesic effect] in a little bit more detail,” he says.

So we looked at ‘Is it really laughter that causes it?’ Because all of the hypotheses that there are related to pain are tied to laughter.”

Ruch and his colleagues made 56 subjects watch a Mr. Bean episode, then subjected them to what’s known as a “cold pressor test.” This test involves submerging a subject’s hand into iced water to see how long they can tolerate it.

They divided their test subjects into three groups: the first group was instructed to laugh out loud in an exaggerated way, the second was told to enjoy the film but to suppress any smiling or laughter, and the final group was asked to produce humorous commentary to go along with the film.

The researchers videotaped the subjects’ facial expressions and measured their pain tolerance before, during and 20 minutes after the film.

Dr. Ruch says he was surprised by the study’s findings.

“We found that laughter itself actually is not really central to the [analgesic] effect. It’s more whether people enjoy themselves or not.

Laughing as much as you can, or commenting on the situations in a funny way didn’t make a difference. The major difference is for the people who showed smiling involving the eyes.”

Don't fake it

This “smiling with the eyes” is also known as the “Duchenne smile”, named after Guillaume Duchenne, a nineteenth century French neurologist who mapped out the muscles of the human face.

Duchenne classified facial expressions according to the muscles used to produce them. He observed that half-hearted or “fake” smiles only involve the muscles around the mouth. And according to Duchenne, a true smile involves contraction of the muscles around the eye – the orbicularis oculi – along with a raising of the cheek by the zygomatic major muscle.

While Ruch found that subjects displaying the Duchenne smile tolerated more pain, the “fakers” didn’t fare so well.

“In our study, any voluntary effort on facial expression, anything which people did which was not genuine…actually reduced the [analgesic] effect.”

Dr. Martin says that discovery is very significant, particularly when you consider things like laughter yoga.

“Laughter is a behaviour. It’s an expression of emotion that conveys to other people that we’re feeling a particular emotion. And the emotion is the feeling of… amusement, mirth, exhilaration. And if there are any benefits for health, it has to do with being genuinely amused. It’s not just, you know, laughing artificially in some bizarre way. It’s the emotion. It’s being amused.”

No laughing matter

Dr. Pierre Rainville, an expert in pain and emotion at the University of Montreal, is impressed with the pain-killing effect that humour seemed to produce.

“The magnitude of the analgesic effect is quite strong. In some cases they’ve doubled the subject’s [pain] tolerance… In pharmacological terms anything that would produce that type of effect would be very clinically significant.”

Dr. Rainville says similar pain tolerance tests are conducted with more traditional analgesics, like morphine. In one type of test - called an ischemic pain test - a subject’s arm is wrapped a tourniquet, cutting off blood flow. Without any painkiller, Dr. Rainville says subjects can tolerate this for about 10 to 15 minutes. With morphine, pain tolerance can be increased to about 25 minutes.

He says Ruch’s participants showed a similar doubling of pain tolerance: subjects were able to withstand having their hands submerged in ice water for 35 seconds without the humorous film, and that was increased up to 55 seconds after they watched. Furthermore, the pain-killing effect seems to last. Something that Dr. Ruch finds encouraging.

“Most studies of humour and pain just looked at a humorous film and then looked at the effects immediately afterwards,” Ruch says.

[But] we could still find the enhanced pain tolerance after 20 or 30 minutes. So maybe there are some delayed and even longer-lasting effects…So the good thing about our study is that it might point into a new direction.”

Ruch and his colleagues are replicating the Mr. Bean study in hopes of getting a better understanding of what’s needed to produce the analgesic effect.

“We have a larger sample, and… we have a more fine-grained observation of all the facial variables so that we can be even more precise.

So now the question will be...‘Does [the Duchenne smile] have to have a certain intensity or duration, or should there be an episode of smiling of at least whatever number of minutes to observe this effect?’… Because this would be essential in the long run for finding a therapy, or for applying [this finding].”

But how the body produces this pain-killing effect is still unknown, although Dr. Martin says there is speculation.

“The hypothesis is that it’s due to endorphins being produced in the brain. And I think that’s a likely hypothesis…But it’s never actually been demonstrated. So we still need to do some research to see whether the effect is mediated by endorphins.”

Locking out pain

Endorphins are the body’s own natural analgesics. They bind to special receptors on nerve fibers, known as opiate receptors, which moderate pain messages heading for the central nervous system and brain.

Receptors are like a lock: only a special key will fit them properly. Like endorphins, certain types of narcotics – like morphine, heroin, methadone and opium – will also fit the opiate receptor “lock”. And like endorphins, they are also effective painkillers.

But other substances can be used to “jam” these receptor-locks, and prevent the key-like substances from binding. In the case of opiate receptors, a drug called naloxone has just that effect. Dr. Martin says naloxone could be useful in determining if endorphins are involved in humour’s apparent pain-killing effect.

Fakin' it: fake smiles like this one only use muscles around the mouth, not the eyes.

“What you do is, you give some participants naloxone and you have other participants that don’t have the drug. And you have them watch a comedy film and you see whether their pain tolerance increases after the film.

The people who had the naloxone…if their pain tolerance does not increase, then that indicates that it’s probably endorphins that are the mediator of the effect.”

But Dr. Rainville says there are other natural analgesics that could be responsible.

“Endorphins are often used to explain any pain modulating effect…But there are several other systems that might be involved. For example, there are pain-modulating conditions where we know that…endorphins are not necessary.”

Dr. Rainville points to studies on the pain-killing effects of hypnosis. Subjects that are hypnotized, then exposed to a cold pressor test, will show higher pain tolerance than non-hypnotized subjects. Surprisingly, subjects that are hypnotized and given naloxone will still show high pain tolerance. This suggests that another substance – one that doesn’t bind to opiate receptors – is involved.

In the case of humour-mediated pain relief, Dr. Rainville suggests a number of potential chemical candidates that the body produces.

“Serotonin, for one, because we know that there are nerve fibres that leave parts of the brainstem and control incoming pain signals. And those nerves communicate using the neurotransmitter serotonin."

Then there’s dopamine – another neurotransmitter that’s involved in reward-related pain relief. And then there are the endogenous cannabinoids. They act like THC, [the active ingredient] in marijuana.”

Dr. Ruch says after replicating the Mr. Bean study, the next step will be to identify what’s happening at a biochemical level.

“But for now, the best would be just to let people enjoy themselves, not really force them into laughter. Just to let people express their way of how they show positive emotions. Whether they habitually do more smiling or laughter, or whatever, rather than tell them to laugh as much and as loud, and as hard and long as possible.”

But John Gupta still maintains there are benefits to faking laughter.

“You fake it ‘til you make it. That’s the whole idea,” he says.

Nevertheless, he says sooner or later his students become genuinely amused with the laughter yoga exercises he teaches, and that means they could benefit from any pain-killing effect that humour may provide.

“After awhile…they don’t fake it anymore. It becomes natural. People realize that it is doing them good. And one thing that I have never heard is somebody that went from my session and said ‘Oh my gosh, laughter makes you feel bad.’ I’ve never heard that yet.”