Dietary Pattern or Weight Loss: Which One Is More Important to Reduce Disease Activity Score in Patients with Rheumatoid Arthritis? A Randomized Feeding Trial

Abstract

Objectives. Herein, disease activity score 28 (DAS 28) was compared between patients with rheumatoid arthritis (RA) receiving the Mediterranean dietary pattern (MD) and low-fat diet. Subjects/Methods. Overweight and obese RA patients aged 15–75 y participated in this randomized feeding trial. Participants were randomized to MD (n = 51) and low-fat high-carbohydrate diet (n = 53) for 12 weeks. The control group followed their regular diet (n = 50). Participants completed the form of tender and swollen joint counts before the study enrollment and after 12 weeks to compute DAS 28. Results. Weight loss was not statistically significant between the MD and LF-HC groups. DAS 28 significantly decreased in MD compared to the LF-HC group ( $p=0.02$ ) and controls ( $p=0.001$ ). Adjusting for the baseline variables, MD reduced DAS 28 by 76% (95% CI = −0.45, −0.2; $p=0.03$ ) after 12 weeks of intervention. The baseline serum ESR level showed 99.8% effect on DAS 28 score at the end (95% CI = 0.014, 0.035; $p<0.001$ ). Conclusions. The MD showed beneficial effects on DAS 28 compared to the LF-HC diet in patients with RA, regardless of weight loss. It is a better dietary choice for pain reduction in patients with RA. The trial is registered at Iranian Registry of Clinical Trials (IRCT20200929048876N2).