Folate intake counteracts breast cancer risk associated with alcohol

provided by Mayo Clinic

he risk of postmenopausal breast cancer increases among women who regularly consume alcoholic beverages if they have a low intake of folate, a B vitamin, according to a new Mayo Clinic study. However, women who choose to drink can lower their risk of developing breast cancer if they take in the Recommended Dietary Allowance (RDA) of 400 micrograms of folic acid, the synthetic form of folate.

    The study, led by Thomas Sellers, PhD, a Mayo Clinic cancer epidemiologist, appears in the May 2001 issue of the journal Epidemiology. In this report, Dr. Sellers and colleagues observe that women with dietary folate intake in the lowest 10th percentile and alcohol use above the median of two grams per day had a 59 percent increased risk of breast cancer compared with women who never drank alcohol and whose folate intake was above the median. They also found that breast cancer risk was almost identical for women who drink four or more grams of alcohol per day but have the highest folate intake, and for teetotalers.

    The interaction between alcohol and folate has been reported previously in two other large cohort studies. Together with the new Mayo Clinic study, these findings jointly suggest that folate supplementation may be an effective strategy to counteract the risks of breast cancer associated with alcohol-containing beverages.

    “Recent surveys of the US population show most people do not get adequate folate,” says Dr. Sellers. “Taking a multivitamin should help individuals meet the RDA just check the label to ensure you're getting 100 percent of the requirement.”

    The precise biological mechanisms by which alcohol and folate interact to impact breast cancer risk are less clear, according to the researchers. There is scientific evidence from other studies that low folate levels may lead to poor DNA repair, which has been linked to occurrence of certain cancers.

    “It is well established that use of alcohol-containing beverages poses a slight increase in the risk of breast cancer, and family history of breast cancer will increase your risk more,” says Dr. Sellers. “Alcohol is metabolized to acetaldehyde, a known carcinogen. People who have adequate folate intake, however, may have a better capacity to repair DNA damage caused by acetaldehyde.”

    The investigators point out that folate may provide a link that helps women balance the health advantages and disadvantages of temperate alcohol consumption.

    “We'd like to offer the benefits of alcohol against cardiovascular disease, but without the consequence of an increased risk for breast cancer,” says Dr. Sellers. “This study adds to the growing body of evidence that if you have adequate folate, you are not increasing your risk of breast cancer by drinking in moderation.”