Dietary inflammatory potential estimated by three metrics and their association with systemic low-grade inflammation...

Inflammatory dietary indices and dietary quality indices are frequently applied to investigate the inflammatory potential of diets. However, their relative ability to explain plasma inflammatory biomarker concentrations remains unclear.

To compare the effectiveness of the Dietary Inflammatory Index (DII), the Empirical Dietary Inflammatory Pattern adapted to the São Paulo population (EDIP-SP), and the Global Diet Quality Score (GDQS) in explaining plasma inflammatory biomarker concentrations.

A cross-sectional population-based study was conducted with 501 participants from the 2015 Health Survey of São Paulo. Dietary data were assessed through two nonconsecutive 24-h dietary recalls, and the DII, EDIP-SP, and GDQS were scored. Plasma concentrations of high-sensitive C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), and adiponectin were determined. Multivariable-adjusted linear regression models were used to investigate the associations between dietary indices and inflammatory biomarkers. Model fit was compared using the coefficient of determination and the Akaike Information Criterion.

The EDIP-SP was positively associated with plasma CRP concentrations in the multivariable analysis adjusted for body mass index. The DII showed an effect modification by sex in association with plasma CRP concentrations. The GDQS submetric composed of healthy food groups was inversely associated with CRP and positively associated with adiponectin concentrations. No significant associations were observed between dietary index scores and plasma TNF-α. No substantial differences in model fit were observed among the dietary indices for explaining plasma inflammatory biomarker concentrations, except for CRP, which presented a higher percentage of variance explained by EDIP-SP.

The EDIP-SP and DII explained plasma inflammatory biomarker concentrations more consistently than the GDQS, indicating that dietary inflammatory indices were more effective for capturing systemic low-grade inflammation.