Journal of the National Cancer Institute
-
J. Natl. Cancer Inst. · Nov 2006
Meta AnalysisMeta-analyses of observational and genetic association studies of folate intakes or levels and breast cancer risk.
Evidence from case-control studies suggests that increasing dietary folate intake is associated with a reduced risk of breast cancer. However, large cohort studies have found no such association, and animal studies suggest that folate supplementation may promote tumorigenesis. We conducted a meta-analysis to summarize the available evidence from observational studies on this issue and a meta-analysis of the association between a common polymorphism in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene, a key enzyme in folate metabolism, and breast cancer risk. ⋯ A lack of dietary folate intake is not associated with the risk of breast cancer.