Breast implants carry a much smaller risk of connective-tissue disorders than previously believed, according to a study released Tuesday by Harvard researchers at Brigham and Women's Hospital.

The study found that there is a statistically significant increase in the risk of connective-tissue disorders as a result of breast implants.

But the increase is much smaller than popularly believed, according to Julie E. Buring, a researcher on the team who is also deputy director of the Division of Preventive Medicine at Brigham and Women's.

"The study has laid to rest the idea that there is a big increase [in the risk]," Buring said in an interview yesterday.

The article found a 24 percent higher risk of developing a connective-tissue disease in women with breast implants. The study took its results from questionnaires filled out by 400,000 female health professionals, including 11,000 who said they currently or previously had breast implants.

Examples of connective-tissue disorders are lupus, rheumatoid arthritis, Sjogren's syndrome and scleroderma.

The research team also concluded that the length of time an implant is in place does not affect the risk of developing a connective-tissue disease.

About 2 million female health professionals received questionnaires; roughly 20 percent of those responded to the survey.

Buring acknowledged yesterday that the study may be biased, since only a self-selected group of women participated in the survey.

Other problems with the survey could stem from the fact that researchers were unable to verify the women's responses with medical records, Buring said.

Buring cited the need for further research. She said that scientists will follow up her team's article with a long-term study of women who do not have connective-tissue disorders.

This would enable researchers to verify medical records, Buring said.

The study was published in yesterday's Journal of the American Medical Association. Snow Professor of Medicine Charles H. Hennekens, was the lead author of the study