Development and evaluation of a nutrient-derived anti-inflammatory dietary index (NADI) among Chinese adults

To develop and evaluate an anti-inflammatory dietary index based on the specific dietary culture and preference among Chinese adults.

A total of 6322 participants were included and were further separated into a training (n = 4514) and a validation set (n = 1808). In the training set, we utilized reduced rank regression to derive a dietary index based on the intake of 33 food groups and five pre-identified anti-inflammatory nutrients. In the validation set, interleukin (IL)-1β, IL-4, IL-6, and high-sensitivity C-reactive protein (hs-CRP) were measured, and a total inflammation score (TIS) was constructed. Pearson partial correlation analysis and multivariate generalized linear regression were applied to explore the relationship between dietary indices and inflammatory biomarkers.

The derived dietary index, termed Nutrient-derived Anti-inflammatory Dietary Index (NADI), mainly characterized by a higher intake of fresh vegetables and fruits, mushrooms and fungi, soybeans, fresh eggs, and tea, alongside a lower intake of red meat, alcohol, and refined grains. NADI significantly correlated with several well-established dietary indices. Participants in the highest quintile of NADI had lower plasma levels of IL-1β (relative concentration [RC]: 0.67, 95% CI 0.58 ~ 0.77), hs-CRP (RC: 0.68, 95% CI 0.58 ~ 0.80), and TIS (RC: 0.43, 95% CI 0.31 ~ 0.59) compared with the lowest quintile in the fully adjusted model. Results were similar in subgroups and sensitivity analyses.

NADI effectively captures inflammation-related dietary quality and could serve as a valuable instrument for evaluating the impact of dietary inflammatory potential on health outcomes in Chinese adults.