No evidence of decreased risk of colorectal adenomas with white meat, poultry, and fish intake: a meta-analysis of observational studies

Purpose: Observational studies on the association between white meat (including fish and poultry) intake and the risk of colorectal adenoma (CRA), the precursor of colorectal cancer, have reported mixed results. To provide a quantitative assessment of this association, we summarized the evidence from observational studies. Methods: Relevant studies published on or before April 30, 2012 were identified from MEDLINE and EMBASE. Summary effect size estimates with 95% confidence intervals (CIs) were calculated with a random-effects model. Between-study heterogeneity was assessed using the Cochran Q and I-2 statistics. Results: A total of 23 publications from 21 independent studies (16 case control and 5 cohort studies) were included in this meta-analysis. Based on high versus low analysis, the summary effect size estimate of CRA was 0.96 (95% CI, 0.84-1.09) for white meat intake, 0.98 (95% CI, 0.80-1.19) for fish intake, and 0.98 (95% CI, 0.80-1.18) for poultry intake. Subgroup analyses revealed that the null associations of CRA with intake of white meat (fish/poultry) were independent of geographic locations, study design, type of food frequency questionnaire, number of cases, and adjustments for confounders, such as body mass index, use of nonsteroidal anti-inflammatory drugs, dietary energy intake, smoking, and physical activity. Conclusions: Intake of white meat (fish/poultry) is not associated with the risk of CRA. (C) 2013 Elsevier Inc. All rights reserved.