Effects of Soy Bread on Cardiovascular Risk Factor, Inflammation and Oxidative Stress in Women With Active Rheumatoid Arthritis: A Randomized Double-Blind Controlled Trial

Abstract

Rheumatoid arthritis (RA) is a systemic inflammatory autoimmune disorder with widespread synovitis. Isoflavones, the main active component of soy, have been reported to have potent anti-inflammatory effects; the previous RA animal models showed the promising effect of soy supplementation. We aimed to evaluate the effect of soy bread on inflammatory markers and lipid profiles in RA patients. The present study was designed as a randomized controlled trial. RA patients were randomly allocated to obtain soy bread (n = 22) or placebo bread (n = 22) for 8 weeks. Fasting serum levels of lipid profile, total antioxidant capacity (TAC), tumor necrosis factor-α (TNF-α), C-reactive protein (CRP), and DAS28 were checked. Findings showed that there were no significant differences between the two groups in physical activity and dietary intake at the beginning of the study and the end of the study. There were no significant differences between the two groups in measured lipid profile markers, including high-density lipoprotein, low-density lipoprotein, total cholesterol, triglyceride, and very low-density lipoprotein, at the end of the trial. In addition, TAC and CRP also were not significant at the end of the trial between the 2 groups (0.66 and 0.12, respectively). However, the serum levels of TNF-α reduced significantly in the soy bread group at the end of the intervention (p < 0.000) and compared with the control group (p < 0.019). Soy bread consumption only decreased circulating TNF-α serum concentration. Other outcome measures were not changed following supplementation. Future long-term, well-designed studies are needed to confirm these findings. Trial Registration Iranian Registry of Clinical Trials Identifier: IRCT20181021041396N1