A new Harvard Medical School study has shown that, despite a popular misconception, obesity may be a leading cause of asthma among children.

Doctors and parents commonly believe that children with asthma become overweight because they are forced to eschew exercise due to their medical condition.

But the study, led by Assistant Professor of Medicine Carlos A. Carmago Jr., makes claims that obesity may lead to asthma among children.

"People have noticed that asthmatics tend to be more overweight," Carmago said. "There has not been much discussion that obesity causes asthma."

Camargo said he began researching the subject in 1996. "We were looking at many risk factors for asthma and [obesity] was one that occurred to us."

Camargo, working primarily with three other researchers, said he "found a rather striking association."

Over the course of three years, Camargo and his team studied 17,000 people between nine and 14 years old. The subjects were all children of registered nurses.

The study, released last week, showed that the more overweight children are, the more likely they are to develop asthma.

However, pediatricians should not automatically conclude that overweight asthmatics can be cured simply by losing weight, Camargo said.

As of yet, his research has not uncovered substantive evidence that weight loss will alleviate asthma, though Camargo hypothesized that in certain cases it might.

"Just speculating, I would guess that asthma caused by obesity will be more likely to go away [with weight loss] than that which is not," he said.

Of course, Cardozo's findings do not mean that obesity always causes asthma.

Tricia M. Michels '00, co-director of the Fitness and Nutrition Program--part of Project Health, a Phillips Brooks House program--said only some of the 9- to 11-year-old overweight girls she mentors have asthmatic problems.

Camargo said the report is likely to prompt other researchers to study the relationship between asthma and obesity in children.

"I think it'll redirect people's attention to other explanations for why asthma has increased so much in our society," he said, mentioning that the prevalence of asthma has doubled since the 1970s.

"There are a lot of people working on this topic now," he added. "We've already sparked a lot of interest in this field."

In the future, Camargo said he plans to do follow-up research to confirm his findings.

"We're going to accrue some more patients so that we can do a more rigorous analysis and then present it," he said.

Camargo said he is optimistic that more research will prove fruitful. "I think we're going to learn more about this problem in the near future," he said.