Questionnaire-Based Anti-Inflammatory Diet Index as a Predictor of Low-Grade Systemic Inflammation

There is accumulating evidence that diet may be associated with markers of inflammation. We have evaluated if an empirically developed questionnaire-based Anti-Inflammatory Diet Index (AIDI) may predict low-grade systemic chronic inflammation in a Nordic population. The AIDI was developed using a 123-item food frequency questionnaire among 3503 women (56-74 years old) with high-sensitivity C-reactive protein (hsCRP) plasma concentration <20 mg/L. Using Spearman correlations, we identified 20 foods (AIDI-20) statistically significantly related to hsCRP. The median (range) of AIDI-20 was 8 (0-17) scores, and the median concentration of hsCRP in the lowest versus the highest quintile of AIDI-20 (≤6 vs. ≥11 scores) varied by 80% (1.8 vs. 1.0 mg/L, respectively). In a multivariable-adjusted linear regression model, women in the highest quintile of AIDI-20 compared with those in the lowest had a 26% (95% confidence interval [CI] 18-33%; p-trend <0.001) lower hsCRP concentration; each 1-score increment in the AIDI-20 was associated with a 0.06 (95% CI 0.04-0.08) mg/L lower hsCRP. The observed association between the AIDI-20 and hsCRP was robust by all hsCRP levels and in subgroups defined by inflammatory-related factors. Our results lead to the hypothesis that the empirically developed questionnaire-based dietary anti-inflammatory index may predict low-grade systemic inflammation. Antioxid. Redox Signal. 28, 78-84.