No link between folate and breast cancer risk?

No firm relationship exists between folate intake or blood folate levels and breast cancer risk, according to a recent meta-analysis of prospective and case–control studies on the subject, but discrepancy exists in the findings.

Researchers included studies from MEDLINE published in any language from the past 40 years. They found that while summary results of prospective studies did not support an association between dietary folate intake and breast cancer, those of case–control studies indicated that an increase of 200 μg/day in dietary folate intake lowered risk for the disease by 20%. In addition, a few of the studies suggested that adequate folate intake might mitigate the increased risk of breast cancer associated with moderate to high alcohol consumption.

The authors of the meta-analysis suggest that large prospective studies be conducted to determine conclusively whether any relationship between the two exists and whether it is influenced by estrogen-receptor status.