title: A high ratio of dietary n-6/n-3 polyunsaturated fatty acids is associated with increased risk of prostate cancer.
abstract: Experimental studies suggest omega-3 (n-3) polyunsaturated fatty acids (PUFA) suppress and n-6 PUFA promote prostate tumor carcinogenesis. Epidemiologic evidence remains inconclusive. The objectives of this study were to examine the association between n-3 and n-6 PUFA and prostate cancer risk and determine if these associations differ by race or disease aggressiveness. We hypothesize that high intakes of n-3 and n-6 PUFA will be associated with lower and higher prostate cancer risk, respectively. A case-control study comprising 79 prostate cancer cases and 187 controls was conducted at the Durham VA Medical Center. Diet was assessed using a food frequency questionnaire. Logistic regression analyses were used to obtain odds ratios (ORs) and 95% confidence intervals (95% CI) for the associations between n-3 and n-6 PUFA intakes, the dietary ratio of n-6/n-3 fatty acids, and prostate cancer risk. Our results showed no significant associations between specific n-3 or n-6 PUFA intakes and prostate cancer risk. The highest dietary ratio of n-6/n-3 was significantly associated with elevated risk of high-grade (OR, 3.55; 95% CI, 1.18-10.69; P(trend) = 0.03), but not low-grade prostate cancer (OR, 0.95; 95% CI, 0.43-2.17). In race-specific analyses, an increasing dietary ratio of n-6/n-3 fatty acids correlated with higher prostate cancer risk among white men (P(trend) = 0.05), but not black men. In conclusion, our findings suggest that a high dietary ratio of n-6/n-3 fatty acids may increase the risk of overall prostate cancer among white men and possibly increase the risk of high-grade prostate cancer among all men.
authors.affiliation: Division of General Internal Medicine, Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA. christina.williams@duke.edu
authors.forename: Christina D
authors.initials: CD
authors.lastname: Williams
authors.forename: Brian M
authors.initials: BM
authors.lastname: Whitley
authors.forename: Cathrine
authors.initials: C
authors.lastname: Hoyo
authors.forename: Delores J
authors.initials: DJ
authors.lastname: Grant
authors.forename: Jared D
authors.initials: JD
authors.lastname: Iraggi
authors.forename: Kathryn A
authors.initials: KA
authors.lastname: Newman
authors.forename: Leah
authors.initials: L
authors.lastname: Gerber
authors.forename: Loretta A
authors.initials: LA
authors.lastname: Taylor
authors.forename: Madeline G
authors.initials: MG
authors.lastname: McKeever
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Freedland
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D016001:Confidence Intervals; D004032:Diet; D004042:Dietary Fats, Unsaturated / Q000378:metabolism*; D015525:Fatty Acids, Omega-3 / Q000378:metabolism*; D043371:Fatty Acids, Omega-6 / Q000378:metabolism*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011471:Prostatic Neoplasms / Q000378:metabolism*; D012307:Risk Factors; D011795:Surveys and Questionnaires
chemical_list: D004042:Dietary Fats, Unsaturated; D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6