Too much folate – a risk factor for cancer and cardiovascular disease?

Authors: SAUER, JULIA - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; Mason, Joel; Choi, Sang-Woon

Submitted to: Current Opinion in Clinical Nutrition and Metabolic Care
Publication Type: Review Article
Publication Acceptance Date: 10/13/2008
Publication Date: 1/12/2009
Citation: Sauer, J.A., Mason, J.B., Choi, S. 2009. Too much folate – a risk factor for cancer and cardiovascular disease?. Current Opinion in Clinical Nutrition and Metabolic Care. 12:30-36.

Interpretive Summary: This review analyzes the role of folate in chronic diseases like cancer and cardiovascular disease. A low status of folate, a water-soluble B vitamin, has been shown to increase the risk of certain cancers and cardiovascular disease but recent folate intervention trials raise concern about possible adverse effects of folate supplementation for individuals who are already at higher risk for cardiovascular disease and cancer. Although sufficient folate intake appears to be an effective agent to prevent cancer a high dose supplementation of folate did not lead to a reduction of cardiovascular events or colorectal adenomas in human trials. Further research is urgently needed to clarify the relationship between folate and chronic diseases.

Technical Abstract: Purpose of review: The intent of this evidence-based review is to analyze the role of folate in chronic diseases, focusing on cancer and cardiovascular disease. Recent findings: Low folate status has been shown to be a risk factor for cancer and cardiovascular disease. While epidemiological data suggest an inverse association between folate status and disease risk, intervention studies give equivocal results, suggesting the response to folate intake does not follow a linear continuum. Recent folate intervention trials raise concern about possible adverse effects of folate supplementation and suggest that too much folate in inopportune settings may be potentially harmful in individuals at higher risk for cardiovascular disease and cancer. Summary: Although sufficient folate intake appears to be an effective cancer chemopreventive agent a high dose supplementation of folate was not effective to reduce recurrence of cardiovascular events or colorectal adenomas in clinical intervention trials. It appears that high folate status through folate fortification or supplementation might be harmful for the chronic disease process in individuals at higher risk by potentially interfering with the homeostasis of one-carbon metabolism. Further research is urgently needed to accurately define the relationship between supraphysiological supplementation of folate and chronic diseases.