An Empirical Dietary Inflammatory Pattern Score Enhances Prediction of Circulating Inflammatory Biomarkers in Adults

Background: Two indexes exist to describe dietary inflammatory potential: an empirical dietary inflammatory pattern (EDIP) composed of food groups as reported on a food-frequency questionnaire (FFQ) and a literature-derived dietary inflammatory index (DII) composed mainly of nutrients. Objective: We compared the ability of the 2 indexes to predict concentrations of inflammatory markers and hypothesized that the EDIP would be more predictive because it was derived on the basis of circulating inflammatory markers. Methods: Both EDIP and DII scores were calculated from FFQ data reported by 5826 women in the Nurses, Health Study II and 5227 men in the Health Professionals Follow-Up Study. We used multivariable-adjusted linear regression analyses to calculate relative differences in concentrations of 4 plasma inflammatory markers-C-reactive protein (CRP; milligrams per liter), interleukin 6 (IL-6; picograms per milliliter), tumor necrosis factor a receptor 2 (TNF alpha R2; picograms per milliliter), and adiponectin (nanograms per milliliter)-in quintiles of the dietary indexes. Results: Spearman correlations between the EDIP and DII scores were modest (r = 0.29 and 0.21 for women and men, respectively; all P < 0.0001). Higher scores on both dietary indexes were associated with higher concentrations of inflammatory markers, although they were associated with lower adiponectin concentrations and there was no association between the DII and adiponectin in men. For example, percentage differences in concentrations of biomarkers in quintile 5 generally were higher (lower for adiponectin) than in quintile 1 (for the EDIP and DII, respectively-women: CRP, +60% and +49%; IL-6, +23% and +21%; TNF alpha R2, +7% and +4%; adiponectin, -21% and -14%; men: CRP, +38% and +29%; IL-6, +14% and +24%; TNF alpha R2, +9% and +5%; adiponectin, -16% and -4%.) Conclusion: Despite design differences, the EDIP and DII both assess dietary inflammatory potential in men and women, with the EDIP showing a greater ability to predict concentrations of plasma inflammatory markers.