Dietary intake of vitamins A, C, and E and the risk of colorectal adenoma: a meta-analysis of observational studiesXu, Xiaodong*; Yu, Enda*; Liu, Lianjie*; Zhang, Wei; Wei, Xubiao; Gao, Xianhua; Song, Ning; Fu, ChuangangEuropean Journal of Cancer Prevention: November 2013 - Volume 22 - Issue 6 - p 529–539 doi: 10.1097/CEJ.0b013e328364f1eb Research Papers: Gastrointestinal Cancer Buy Abstract Author InformationAuthors Article MetricsMetrics To comprehensively summarize the association between dietary intake of vitamins A, C, and E and the risk of colorectal adenoma (CRA), the precursor of colorectal cancer, relevant studies were identified in MEDLINE and EMBASE up to 31 October 2012. Summary relative risks (SRRs) with 95% confidence intervals (CIs) were pooled with a random-effects model. Between-study heterogeneity was assessed using Cochran’s Q and I 2 statistics. A total of 13 studies with 3832 CRA cases were included in this meta-analysis. On the basis of the highest versus lowest analysis, dietary intake of vitamin C reduced the risk of CRA by 22% (SRRs 0.78, 95% CIs: 0.62–0.98). Subgroup analyses showed that this relation was not modified by BMI, smoking status, and dietary energy intake. Further, dietary intake of β-carotene was also inversely associated with the risk of CRA. However, dietary intake of vitamins A and E was not associated with the risk of CRA in overall and subgroup analyses (vitamin A: SRRs 0.87, 95% CIs: 0.67–1.14; vitamin E: SRRs 0.87, 95% CIs: 0.69–1.10). Our results indicate that dietary intake of vitamin C and β-carotene, but not vitamins A and E, could reduce the risk of CRA. However, these associations seem to be limited. Further investigation using large samples and a rigorous methodology is warranted. Department of Colorectal Surgery, Changhai Hospital of Second Military Medical University, Shanghai, China *Xiaodong Xu, Enda Yu, and Lianjie Liu contributed equally to the writing of this article. Correspondence to Chuangang Fu, MD, Department of Colorectal Surgery, Changhai Hospital of Second Military Medical University, 168 Changhai Road, Shanghai 200433, China Tel/fax: +86 21 81873337; e-mail: email@example.com Received January 10, 2013 Accepted June 29, 2013 © 2013 Lippincott Williams & Wilkins, Inc.