Last Updated: 2003-05-22 11:26:38 -0400 (Reuters Health)

NEW YORK (Reuters Health) - A small study shows that diabetics may be better able to process the sugar they consume during meals if they order a side of laughter with their food.

Laugh if you will, but a group of researchers in Japan found that people with type 2 diabetes -- the most common form of the disease -- had a smaller rise in post-meal blood glucose (sugar) when they watched a comedy show than when they listened to a humorless lecture.

The researchers, led by Dr. Keiko Hayashi from the University of Tsukuba, also found the same results in people without diabetes.

Poorly controlled blood sugar can increase the risk of diabetes complications such as heart disease, kidney failure and blindness.

Hayashi told Reuters Health that people with diabetes have a lot to worry about -- diet, exercise and keeping their glucose and insulin levels in check. And stress is known to increase the risk of elevated blood glucose, the researcher noted.

"If positive emotion such as laughter reduced blood glucose, both patients and medical providers would recognize the importance of it, and it would improve their mental health" and quality of life, Hayashi said.

"We should laugh more," the researcher added.

Plenty of studies have shown that laughter can combat many common ills. For instance, research suggests that humor may lower blood pressure and release endorphins.

Laughter is also thought to improve circulation, stimulate the nervous system, heighten the immune system and make the heart stronger.

All of the diabetic patients included in the study had type 2 diabetes, which occurs when the body fails to respond to insulin, the hormone that clears the blood of sugar after a meal and deposits it into cells to use for energy.

During the study, reported in the May issue of the journal Diabetes Care, Hayashi and colleagues measured the blood glucose levels of 19 diabetics and five non-diabetics before and after they ate the same meal, on two separate days.

On one day, participants listened to a 40-minute lecture, which the researchers describe as "monotonous" and "without humorous content." On the second day, participants were included in an audience of 1,000 people who watched a Japanese comedy show.

At the end of the show, "most" participants "considered that they laughed well," the authors note.

The researchers found that post-meal blood glucose levels were higher after the boring lecture than after the comedy show, in diabetics and non-diabetics alike.

Hayashi noted that the reasons why laughter might reduce blood glucose are not clear, but suggested that laughter could increase energy consumption by working the abdominal muscles.

Alternatively, the researcher said, laughter might affect the neuroendocrine system, which controls glucose levels in the blood.