Folic acid supplementation and colorectal cancer risk: a meta-analysis

J. Fife, S. Raniga, P. N. Hider, F. A. Frizelle*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

46 Citations (Scopus)


Aim: This meta-analysis aims to determine the effect of folic acid supplementation on colorectal cancer risk. Method: A structured search of the MEDLINE, EMBASE, Cochrane and CINAHL databases was undertaken in July 2008. All published full text English language articles were searched that included a randomized or pseudo-randomized comparison of subjects who received folate vs subjects who did not in relation to their risk of adenoma or advanced adenomatous lesions, including colorectal cancer. A weighted treatment effect (using fixed effects) was calculated across trials. Results: Overall, the risk of an adenomatous lesion was not increased (odds ratio 1.09, 95% confidence interval 0.93-1.28) among patients who received folate supplementation for up to 3 years; however, for those who received folate for over 3 years, the risk of an adenomatous lesion was increased (odds ratio 1.35, 95% confidence interval 1.06-1.70). The risk associated with treatment was the highest for the occurrence of an advanced lesion (odds ratio 1.50, 95% confidence interval 1.06-2.10). There was no significant statistical heterogeneity in the analyses. Conclusion: At the 3-year colonoscopic follow up, folate supplementation had no effect on adenoma recurrence overall. While colonic surveillance beyond 3 years revealed an increased risk of colorectal adenoma, especially advanced adenoma, among those participants randomized to the folate group. This meta-analysis challenges the results from epidemiological studies that folate status is inversely related to the risk of developing colorectal cancer.

Original languageEnglish
Pages (from-to)132-137
Number of pages6
JournalColorectal Disease
Issue number2
Publication statusPublished - 1 Feb 2011
Externally publishedYes


  • Adenoma
  • Colorectal cancer
  • Folate
  • Folic acid
  • Meta-analysis


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