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

Abstract

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 α receptor 2 (TNFαR2; 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%; TNFαR2, +7% and +4%; adiponectin, -21% and -14%; men: CRP, +38% and +29%; IL-6, +14% and +24%; TNFαR2, +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.

Keywords: dietary indexes; dietary patterns; dietary quality; inflammation; inflammatory markers.

FIGURE 1

The proportion of total variance in biomarker concentration explained by separate models for the food-based EDIP, the nutrient-based, literature-derived DII, and a CDII in women (A) and men (B). Models for the EDIP, DII, and CDII were adjusted for age at blood draw, physical activity, smoking status, case-control status, regular aspirin or nonsteroidal anti-inflammatory drug use, menopausal status, postmenopausal hormone use (in women), and an inflammation-related chronic disease comorbidity score. Chronic diseases or conditions included in the score (presence = 1, absence = 0) were hypercholesterolemia, cancer, diabetes, high blood pressure, heart disease, and rheumatoid or other arthritis. ADIP, adiponectin; CDII, composite dietary inflammatory index; CRP, C-reactive protein; DII, dietary inflammatory index; EDIP, empirical dietary inflammatory pattern; TNFαR2, TNF-α receptor 2.