More than 88,800 women participated in the study and almost 3,500 cases of breast cancer were documented at the end of a 16-year period. The results of the study, which were published in the May 5, 1999, issue of The Journal of the American Medical Association (JAMA), suggest folate, while not reducing the risk of breast cancer in all women, had an effect on those who drank at least one alcoholic drink per day.

According to study author Shumin Zhang, MD, ScD, of the department of nutrition at Harvard?s School of Public Health, low folate intake is associated with increased tumor occurrence in animal models, and folate itself is involved in DNA synthesis. Because alcohol is a known "folate antagonist," Dr. Zhang and his colleagues hypothesized that higher folate intake may reduce the risk of cancer among drinkers.

But taking folate every day will not help women who have a genetic risk for breast cancer."Epidemiologic studies consistently have shown women who consumed moderate amounts of alcohol will have a higher risk of developing breast cancer. Increased folate was beneficial for women who consumed alcohol, from the findings of our study. However, we did not see the difference in the association between folate and breast cancer for women who had a family history of breast cancer and those who did not have such a history," Dr. Zhang said.

The Harvard study also did not suggest folate could reduce cancer tumors or fight the disease ? just aid in reducing the risk, he warned.

Because this is the first study of its kind, more studies need to be conducted, according to Michael Thun, MD, vice president of epidemiology and surveillance research for the American Cancer Society (ACS).

This study and another Harvard Nurses? Health Study -- of the relationship between folate intake and colorectal cancer among drinkers -- fit into a larger debate about further supplementation of grains with folic acid, said Dr. Thun."The Institute of Medicine, part of the National Academy of Sciences, recommends all Americans should consume 400 micrograms a day of folate in food. Only a small percentage of people achieve this RDA, "he added.

In 1998, grain products were enriched with folic acid to provide the average woman 100 micrograms of additional folic acid daily, according to Dr. Thun. Because multivitamins now have 400 micrograms of folic acid, they are another source of folate, which is especially important for pregnant women and women of childbearing age, Dr. Thun added.

The author of the Harvard study agreed. Dr. Zhang recommended women "increase their intake of folate by increasing consumption of green leafy vegetables and fruits, particularly if they consume alcohol."