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Research: XU and COLLEAGUES,
Listed in Issue 242
Abstract
XU and COLLEAGUES, (1)Department of Colorectal Surgery, Changhai Hospital of Second Military Medical University, Shanghai, China analyzed and quantified the association between dietary intake of vitamins A, C, and E and the risk of colorectal adenoma (CRA), the precursor of colorectal cancer.
Background
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.
Methodology
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 statistics. A total of 13 studies with 3832 CRA cases were included in this meta-analysis.
Results
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).
Conclusion
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.
References
Xu X(1), Yu E, Liu L, Zhang W, Wei X, Gao X, Song N, Fu C. Dietary intake of vitamins A, C, and E and the risk of colorectal adenoma: a meta-analysis of observational studies. Eur J Cancer Prev. 22(6):529-39. doi: 10.1097/CEJ.0b013e328364f1eb. Nov 2013.