The Source: American Physiological Society's Experimental Biology Meeting, San Francisco

The Study: More suggestive evidence that laughter that is full of mirth is good for the body. Lee Berk of Loma Linda University took 16 healthy men who had been fasting and hadn't exercised for at least a day, and asked each to pick a video he knew he'd laugh out loud at. Half the subjects were then told they'd get to watch the video, while the other half wouldn't. Berk took blood samples before, during and after the experiment from all subjects, and found that the men who got to watch had 27% more beta-endorphins and 87% more human growth hormone in their blood.

What It Means: It's hard to say anything definitive from a study that is so small. However, previous (also small) studies have shown that "mirthful laughter" reduces blood levels of cortisol and epinephrine—hormones associated with stress and an impaired immune system.

This latest research doesn't prove that laughter is  beneficial, but it provides more evidence that there is in fact a hormonal response to laughter or the anticipation of laughter. And if you want to study the potential health benefits of laughter, you have to start somewhere.

From our Archive:
01/09/2005 The Funny Thing About Laughter