In the last 20 years, some studies have suggested that low folate intake is associated with an increased risk of several cancers, including breast cancer. Additional studies have found that that the increase in breast cancer risk associated with alcohol consumption can be reduced by adequate folate intake. Susanna C. Larsson, of the Karolinska Institute in Stockholm, and colleagues performed a meta-analysis of nine prospective studies and 14 case-control studies of folate intake and risk of breast cancer.

Overall, there was no association between total folate intake or blood folate levels with breast cancer risk. They did find an association between dietary folate intake and reduced breast cancer risk among the case-control studies; however, no such association was found among the prospective studies. Their findings also suggest that high folate intake might be associated with a reduced risk of breast cancer in women with moderate or high consumption of alcohol.

"There was evidence from prospective studies that adequate folate intake may attenuate the increased risk of breast cancer associated with alcohol consumption," the authors write. "Large prospective studies that investigate interactions between folate and other nutrients involved in one-carbon metabolism, alcohol consumption, and functional polymorphisms in genes encoding folate-metabolizing enzymes are needed to further clarify the role of folate in breast cancer etiology."

By: Journal of the National Cancer Institute