This colonoscopy-based case-control study was conducted to examine the associations of dietary polyunsaturated fatty acids (PUFA) intake on risk of colorectal adenomatous and hyperplastic polyps. Subjects included 3,166 polyp-free control subjects, 1,597 adenomatous polyp cases, and 544 hyperplastic polyp cases. Dietary PUFA intake was calculated from food-frequency questionnaires and urinary prostaglandin E2 metabolite was measured in 896 participants by using liquid chromatography and tandem mass spectrometry. ω−6 PUFA were not associated with adenomatous or hyperplastic polyps in either men or women. In women only, marine-derived ω−3 PUFA were associated with reduced risk of colorectal adenomas for the highest versus lowest quintile of intake (adjusted OR 0.67; 95% CI 0.47-0.97; P-trend = 0.01) and negatively correlated with urinary prostaglandin E2 production (r = −0.18; P = 0.002). Dietary intake of α-linolenic acid was associated with an increased risk of hyperplastic polyps in men (P-trend = 0.03) but this was not seen in women. Therefore, higher intakes of marine-derived ω−3 PUFA are associated with lower risk of adenomatous polyps in women and the association may be mediated in part through a reduction in the production of prostaglandin E2. Am J Clin Nutr. 2012 Mar;95(3):703-12. PMID: 22277551
