Proposed Anti-Inflammatory Diet Reduces Inflammation in Compliant, Weight-Stable Patients with Rheumatoid Arthritis in a Randomized Controlled Crossover Trial

Abstract

BackgroundIt is unclear to what extent adjuvant dietary intervention can influence inflammation in rheumatoid arthritis (RA). ObjectivesThe objective was to assess the effects of dietary manipulation on inflammation in patients with RA. MethodsIn a crossover design, participants [n = 50, 78% females, median BMI (in kg/m2) 27, median age 63 y] were randomly assigned to begin with either a 10-wk portfolio diet of proposed anti-inflammatory foods (i.e., a high intake of fatty fish, whole grains, fruits, nuts, and berries) or a control diet resembling a Western diet with a 4-mo washout in between. This report evaluates the secondary outcome markers of inflammation among participants with stable medication. Analyses were performed using a linear mixed ANCOVA model. ResultsThere were no significant effects on CRP or ESR in the group as a whole. In those with high compliance (n = 29), changes in ESR within the intervention diet period differed significantly compared with changes within the control diet period (mean: –5.490; 95% CI: –10.310, –0.669; P = 0.027). During the intervention diet period, there were lowered serum concentrations of C-X-C motif ligand 1 (CXCL1) (mean: –0.268; 95% CI: –0.452, –0.084;P = 0.006), CXCL5 (mean: –0.278; 95% CI: –0.530, –0.026 P = 0.031), CXCL6 (mean: –0.251; 95% CI: –0.433, –0.069; P = 0.009), and tumor necrosis factor ligand superfamily member 14 (TNFSF14) (mean: –0.139; 95% CI: –0.275, –0.002; P = 0.047) compared with changes within the control diet period. ConclusionA proposed anti-inflammatory diet likely reduced systemic inflammation, as indicated by a decreased ESR in those who completed the study with high compliance (n = 29). These findings warrant further studies to validate our results, and to evaluate the clinical relevance of changes in CXCL1, CXCL5, CXCL6, and TNFSF14 in patients with RA.