Folate Increases Breast Cancer Risk

ATLANTAResults published in the American Journal of Clinical Nutrition suggest dietary folate intake may be positively associated with postmenopausal breast cancer; however, no dose-response relation was observed (April 21, 2010). Researchers at the American Cancer Society investigated the association of dietary (food folate plus folic acid from fortification) and total folate (food folate, folic acid from fortification, and folic acid from supplements), vitamin B6 and B12, methionine and alcohol intakes with postmenopausal breast cancer among women in the Cancer Prevention Study II Nutrition Cohort. The prospective cohort study included 70,656 postmenopausal women for whom dietary information was collected in 1992. Of these, 3,898 developed breast cancer between enrollment in 1992 and June 2005.

Compared with the lowest quintile, the highest quintile of dietary folate intake was associated with a higher risk of breast cancer. However, the test for trend was not significant (P for trend = 0.15). No association was found for total folate, vitamin B6 or B12, but methionine was inversely associated with breast cancer risk (P for trend = 0.04). The association of dietary folate with breast cancer was not modified by other nutrients or alcohol. Researchers noted, The extent to which increased supplement use and folate fortification contributes to breast cancer risk warrants further research.