Use of oral contraceptives can increase slightly the risk of heart disease in some older women, according to a study by Harvard researchers published today.

Women who use oral contraceptives when they are young do not face increased risk of heart disease after they stop taking the pill, said Meir J. Stampfer, an associate professor of epidemiology at the School of Public Health and one of the researchers.

But older women who are currently using birth control pills, and especially those who smoke, do face an increased risk, Stampfer said yesterday.

"As soon as a women stops using oral contraceptives her risk [of heart disease] is the same as a women who never used oral contraceptives," Stampfer said.

"Women who currently use oral contraceptives are at slightly higher risk."

Stampfer's findings, which are published in today's New England Journal of Medicine, were part of the eight-year Nurse's Health Study conducted by the Medical School. The data were based on bi-annual questionnaires of 120,000 women from 11 states, Stampfer said.

Like smoking, oral contraceptive use might influence blood coagulation, a factor in heart disease, Stampfer said. The contraceptives tend to compound the affects of smoking, a factor in about half of all heart disease cases in women, he said.

Stampfer's study received praise from a researcher who is also examining the affect of oral contraceptives on heart disease. "His is a very large study, [which was] well conducted. I think it's a pretty convincing study," said Lynn Rosenberg, director of the Slone Epidemiology Unit at Boston University Medical School.

Rosenberg said that the findings of a three-year study at the Slone center were consistent with Stampfer's work. "Our preliminary results are very similar to what Dr. Stampfer will publish tommorrow," she said yesterday.