In what is believed to be the first large epidemiological study on dietary habits and colorectal cancer (colon cancer or large bowel cancer) incidence in Eastern Europe, it was determined that increased fish consumption has a preventive effect on colorectal cancer and modulates the effect of meat consumption. Excessive red and processed meat intakes have been positively associated with colorectal cancer.

This hospital-based case-control study was performed in 548 colorectal cancer patients between November 2000 and May 2008. The control group consisted of 745 patients of the same hospital with no history of cancer admitted for treatment of non-cancer related conditions. During the 5-year study period, a food frequency questionnaire was used to gather necessary data.

The risk of colorectal cancer increased with intake of stewed or cooked meat, and there was a significant reduction in colorectal cancer already at the moderate fish intake of one or two servings per week, but there was an even lower risk of colorectal cancer at higher fish consumption. All multivariate statistical models employed in the analysis considered potential confounders, such as demographic characteristics of subjects, body mass index, smoking status, leisure time physical activity, energy consumption and intake of meat products.
References:
1. Jedrychowski W, Maugeri U, Pac A, Sochacka-Tatara E, Galas A. Protective Effect of Fish Consumption on Colorectal Cancer Risk. Ann Nutr Metab. 2009 Jan 26;53(3-4):295-302. PMID: 19169007.
2. Cross AJ, Leitzmann MF, Gail MH, Hollenbeck AR, Schatzkin A, Sinha R. A prospective study of red and processed meat intake in relation to cancer risk. PLoS Med. 2007 Dec;4(12):e325. PMID: 18076279.