Abstract A109: Intake of polyunsaturated fatty acids and distal large bowel cancer risk in whites and African Americans

Abstract

Abstract Experimental and clinical data suggest anti-neoplastic properties of long-chain ω-3 polyunsaturated fatty acids in the colon. Epidemiologic evidence is inconclusive. We examined the association between intakes of different polyunsaturated fatty acids and distal large bowel cancer in a population-based case-control study of 1,509 whites (716 cases and 787 controls) and 369 African Americans (213 cases and 156 controls) in North Carolina (2001–2006). Dietary intake of 19 different polyunsaturated fatty acids was assessed using a validated food frequency questionnaire. Unconditional logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) for distal large bowel cancer risk in relation to quartiles of polyunsaturated fatty acid intake. Increased consumption of long-chain ω-3 fatty acids was associated with reduced risk of distal large bowel cancer. Compared to the lowest quartile, the multivariable odds ratios for the second, third and highest quartile were: OR=0.96 (95% CI: 0.71–1.31), OR=0.75 (95% CI: 0.54–1.04), and OR=0.61 (95% CI: 0.44–0.86), respectively; P for trend<0.01). Intake of individual eicosapentanoic acids and docosahexanoic acids was similarly inversely related to distal large bowel cancer risk, whereas the ratio of ω-6 to long-chain ω-3 fatty acids was associated with increased risk of distal large bowel cancer. These associations were limited to whites, and not observed among African Americans (likelihood ratio test for interaction p<0.01). There was no evidence of effect measure modification by nonsteroidal anti-inflammatory drug use, obesity, or tumor location. Our results support the hypothesis that long-chain ω-3 polyunsaturated fatty acids have beneficial effects in colorectal carcinogenesis. Whether or not the possible benefit of long-chain ω-3 fatty acids varies by race warrants further evaluation. Citation Information: Cancer Prev Res 2010;3(1 Suppl):A109.