Plant-based dietary indices and biomarkers of chronic low-grade inflammation: a cross-sectional analysis of adults in Ireland

Linear regression models, adjusted for potential confounders, showed that higher hPDI scores were associated with lower concentrations of complement component 3 (C3), tumor necrosis factor-alpha (TNF-α), white blood cells (WBCs), neutrophils, and monocytes. Conversely, higher uPDI scores were associated with higher concentrations of C3 and TNF-α. The authors suggest these findings may provide a biological mechanism linking healthy plant-based diets to reduced cardiovascular disease risk, but note the cross-sectional design prevents causal inference. Other limitations include potential recall bias from self-reported dietary data and limited generalizability beyond the studied population.