Folate and colon cancer: dietary habits from the distant past coming home to roost

Authors: MASON, JOEL - Jean Mayer Human Nutrition Research Center On Aging At Tufts University

Submitted to: The American Journal of Clinical Nutrition
Publication Type: Other
Publication Acceptance Date: 5/1/2021
Publication Date: 5/8/2021
Citation: Mason, J.B. 2021. Folate and colon cancer: dietary habits from the distant past coming home to roost. American Journal of Clinical Nutrition. 114(1):1-2. https://doi.org/10.1093/ajcn/nqab117.
DOI: https://doi.org/10.1093/ajcn/nqab117

Interpretive Summary:

Technical Abstract: A large body of evidence indicates that habitually low consumption of the B-vitamin, folate, increases the risk of colon cancer. More controversial are some reports that suggest that excessive intake of the vitamin may paradoxically increase the risk. This editorial summarizes the new insights provided by an epidemiological study that examined these issues in the well-known Nurse's Health Study that is based at the Harvard School of Public Health, and the focus of this study was to attempt to define the window of time during which the consumption of folate is most critical in determining the risk of developing colon cancer. The results indicate that it is the consumption of folate 10+ years prior to the diagnosis of colon cancer-and not more recent intake of folate--that is the critical time window that determines this risk, which is consistent with the observation that colon cancer slowly evolves over a decade. The study also examined whether there was any signal from the data that suggested that excessive intake of folate might paradoxically increase the risk and no such signal was detected. However, the latter conclusion must be interpreted with the understanding that large epidemiological studies such as this often cannot detect effects that exist in sub-groups that might be particularly susceptible to the effects of excess folate consumption.