Association between dietary inflammatory potential and rheumatoid arthritis: Evidence from the NHANES 2003 to 2018

Rheumatoid arthritis (RA) affects approximately 17.6 million people globally. While genetic factors contribute to RA development, dietary patterns may influence disease onset and progression. This study investigated the relationship between dietary inflammatory potential and RA prevalence using data from 25,137 adults (≥20 years) in the National Health and Nutrition Examination Survey (NHANES) 2003 to 2018. Dietary inflammatory potential was assessed using the dietary inflammatory index (DII) and energy-adjusted DII (E-DII). RA status was based on self-reported physician diagnosis. Weighted logistic regression models were used. Participants with RA had significantly higher DII (1.11 ± 1.53 vs 0.76 ± 1.61) and E-DII (0.95 ± 1.26 vs 0.67 ± 1.16) scores compared to those without RA. In fully adjusted models, each unit increase in DII or E-DII was associated with 9% higher odds of RA (DII: OR = 1.09, 95% CI: 1.05-1.13; E-DII: OR = 1.09, 95% CI: 1.04-1.14). Individuals in the highest DII/E-DII quartiles showed 36% higher odds of RA compared to the lowest quartiles (both OR = 1.36, 95% CI: 1.15-1.61). Stronger associations were observed among young adults (20-39 years) and physically active individuals. Higher dietary inflammatory potential is significantly associated with increased RA prevalence, particularly among younger and physically active individuals. These findings suggest that reducing dietary inflammatory potential might be a promising strategy for RA prevention and management.