As adults, we laugh about 15 times a day. Sounds pretty joyful - until you find out that children laugh about 400 times in a 24-hour go-round. That is a pretty big giggle gap!

Kids get it right, too, according to gelotologists. No, that's not a scholar of gelatin desserts. Gelotology (from the Greek gelos, which means "to laugh") is the study of laughter and its effects on our body and mind. As it turns out, laughter provides health benefits that are nothing to snicker at.

Laughing may reduce stress

You know how a good laugh can feel like an escape? Well, laughter actually has the power to stop the body's stress response in its tracks. In a small study, Dr. Lee Berk (an immunologist who has investigated laughter's benefits since the 1970s) found that real, "mirthful" laughter could slash stress hormone levels. And since stress hormones can suppress our immune system, laughter may be a way to protect our body's best defences.

Even just the anticipation of laughter that's about to happen can make us feel better. Dr. Berk discovered this when he was setting up laughter studies. He noticed that people's levels of endorphins, the so-called "feel-good" hormones, would rise right before they were about to be shown or told something funny.

Laughter also engages our muscles. Once we've stopped laughing, those muscles relax - and that muscle relaxation can last up to about 45 minutes. And it's usually cheaper than a massage, too.

Laughing may support a healthy heart

Ever heard of laughter yoga? If you haven't, you might want to take this to heart: After just seven sessions of laughter yoga, many research participants in one study saw a significant reduction in their blood pressure. The sessions consisted of 45-second rounds of simulated laughter followed by deep breathing and gentle stretching exercises; this process was repeated during the 20- to 30-minute session.

In another study measuring response to humour, it was noted that people with heart disease seemed to be more angry and hostile and less likely to laugh at ridiculous or joyous moments from everyday life. Perhaps the heart-healthy benefit of laughter comes from not just the physical act of deeper, quicker breathing, but also from a light-hearted, laugh-it-off attitude.

Laughing may sharpen our minds

A Marquette University psychologist had people read a list of words, and then some of them were shown a funny video clip. A week later, those who had the chance to chuckle at the clip recalled 20 percent more words than those who hadn't had the laugh break. It's thought that the rush of laughter speeds up the heartbeat and sends more oxygen to the brain, which could boost memory skills.

Laughter can be therapeutic

Many cancer patients try humour therapy as part of their treatment, and are able to better cope with cancer and cancer treatment because of the jolt of laughter they add to their lives. Children who laugh during painful medical procedures may be able to tolerate pain better. And they don't even have to laugh out loud to feel the soothing benefits.

Laughter yoga, mentioned above for its heart-healthy benefits, has caught on as well. More than 5,000 laughter yoga clubs have opened around the world. In these clubs, participants walk around together, breathing and chanting "ho ho, ha ha" while engaging their abdominal muscles. Dr. Madan Kataria, founder of laughter yoga, notes that while the laughter in his sessions may start off phony, "when we have eye contact with others, this laughter becomes real and contagious." Kataria contends that laughter yoga strengthens the abdominals to help support a healthy digestive system, stimulates the circulatory system, and strengthens the respiratory system.

But can laughter replace your cardio workout?

When we laugh, our heart beats faster. Our blood flow also increases - about as much as it would after taking cholesterol-lowering medications or during light exercise. Lazy optimists sometimes interpret this to mean that laughter is a good alternative to cardio. Ha! Not exactly. It's been estimated that 20 seconds of laughter would equal about 3 minutes on the rowing machine, but even the best, biggest belly laugh session can't replace a good run on the treadmill. So, hearty laughter is more like a really light, brief aerobic workout. Let out a good laugh more often, though, and you may have more energy and help your body to reverse some of the effects of excess stress.

Basically, laughing feels good, and it can undoubtedly perk up a bad mood. While it may not be the best medicine, wouldn't you take it anyway?

Amy Toffelmire