Background: A Westernized diet and lifestyle is associated with risk for colorectal cancer and adenomas. Evolutionary discordance could explain this association.
Objective: We investigated associations of scores for two proposed healthy diet patterns, the “Paleolithic” and Mediterranean diets, with risk for incident, sporadic colorectal adenomas.
Methods: In the Minnesota Cancer Prevention Research Unit case-control study of colorectal polyps, 1,248 participants with no history of colorectal neoplasms completed extensive questionnaires, including a Willett food frequency questionnaire, prior to an elective, outpatient colonoscopy. Of these participants 564 were identified as cases and 684 as colonoscopy-negative controls. An additional group of 535 age and sex frequency-matched population controls were also recruited. Paleolithic and the Mediterranean diet scores were calculated and categorized into quintiles, and associations estimated using unconditional logistic regression.
Results: The Paleolithic and the Mediterranean diet patterns were similarly inversely associated with colorectal adenomas. The multivariable-adjusted odds ratios [OR] comparing those in the highest relative to the lowest quintiles of the Paleolithic and Mediterranean diet scores, respectively, were 0.51 (95% confidence interval [CI] 0.35-0.76) and 0.50 (95% CI 0.33-0.75) when comparing the cases to the colonoscopy negative controls, and 0.66 (95% CI 0.45 - 0.96, ptrend = 0.03) and 0.65 (95% CI 0.44 - 0.96, ptrend = 0.03) when comparing the cases to the population controls. These findings tended to be somewhat stronger among men and those who were overweight or obese.
Conclusion: These findings suggest that higher adherence to the Paleolithic or Mediterranean diet patterns may be similarly associated with lower risk for incident, sporadic colorectal adenomas.
Citation Format: Kristine A. Whalen, Baiyu Yang, Roberd M. Bostick. Paleolithic and Mediterranean diet scores and risk of colorectal adenoma. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4816. doi:10.1158/1538-7445.AM2013-4816