Associations of Novel Dietary and Lifestyle Inflammation Scores with Incident, Sporadic Colorectal Adenoma.

BACKGROUND: Colorectal carcinogenesis is mechanistically linked to inflammation and is highly associated with diet and lifestyle factors that may affect chronic inflammation. We previously developed dietary (DIS) and lifestyle (LIS) inflammation scores, comprising inflammation biomarker-weighted components, to characterize the collective contributions of 19 food groups and four lifestyle exposures to systemic inflammation. Both scores were more strongly directly associated with circulating inflammation biomarkers in three validation populations, including a subset of the study population described below, than were the previously reported dietary inflammatory index and empirical dietary inflammatory pattern.
METHODS: We calculated the DIS and LIS in three pooled case-control studies of incident, sporadic colorectal adenoma (N = 765 cases and 1,986 controls) with extensive dietary and lifestyle data, and investigated their associations with adenoma using multivariable unconditional logistic regression.
RESULTS: For those in the highest (more proinflammatory) relative to the lowest (more anti-inflammatory) quintiles of the DIS and LIS, the multivariable-adjusted ORs were 1.31 [95% confidence interval (CI), 0.98-1.75; P trend = 0.09] and 1.98 (95% CI, 1.48-2.66; P trend < 0.001), respectively. These associations were strongest for adenomas with high-risk characteristics and among men. Those in the highest relative to the lowest joint DIS/LIS quintile had a 2.65-fold higher odds (95% CI, 1.77-3.95) of colorectal adenoma.
CONCLUSIONS: These results support that diets and lifestyles with higher balances of pro- to anti-inflammatory exposures may be associated with higher risk for incident, sporadic colorectal adenoma. IMPACT: Our findings support further investigation of the DIS and LIS in relation to colorectal neoplasms. ©2020 American Association for Cancer Research.