Short-term use of folic acid, a B vitamin added to food in many countries to prevent birth defects, is unlikely to significantly increase cancer risk, according to a review of results from 13 studies.
Among people who took folic acid supplements daily for five years or less, 7.7 percent reported new cases of cancer, compared with 7.3 percent among those who took a placebo, according to an analysis of studies involving almost 50,000 individuals through the end of 2010. The review was published today in the Lancet medical journal.
The analysis, conducted by researchers participating in the B-Vitamin Treatment Trialists’ Collaboration affiliated with Oxford University, contradicts findings from previous research that suggested an increased risk of developing cancer from taking folic acid. Even among those with the highest average intake, there was no significant increase in overall incidence, the researchers said in a statement about the paper.
“Both the hopes for rapid cancer prevention and the fears about rapidly increased cancer risk from folic acid supplementation were not confirmed by this meta-analysis,” the authors said in the published paper.
The supplement dose of folic acid used in the studies covered by the analysis was about 10 times higher than the dose of fortification used in the U.S., Joshua Miller of Rutgers University’s Department of Nutritional Science in New Jersey and Cornelia Ulrich of the German Cancer Research Center in Heidelberg, Germany, noted in a comment accompanying the paper.
“Additional epidemiological and statistical analyses are warranted to address population-based hypotheses that are consistent with our current understanding of the biochemistry and biology of folate and cancer,” they said.