The association between dietary total antioxidant capacity with risk of rheumatoid arthritis in adults: A case-control study.

ABSTRACT

OBJECTIVE: Rheumatoid arthritis (RA) is a chronic disease associated and oxidative stress. The critical role of a dietary antioxidant in increasing the antioxidant defense system is undeniable and makes the assessment of the potential link between dietary antioxidants and diseases informative. Given the limited available data on dietary antioxidants, this study aimed to evaluate the association between DTAC and the risk of RA. METHODS: This case-control study was carried out on 100 patients with RA and 197 healthy individuals aged 19-69 years. Data on dietary intake were collected using a validated 168-items quantitative food frequency questionnaire. DTAC was calculated based on the ferric reducing ability of plasma (FRAP), the ability of dietary antioxidants to reduce ferric to ferrous ions, presented in mmol per 100 g of foods (mmol/100 g). To find the association between DTAC and risk of RA, binary logistic regression adjusted for potential confounders was used. RESULTS: The mean age of the study participants was 49.26 and 40.88 years in the case and control groups, respectively. Participants in the top tertile of DTAC were less likely to have RA in the crude model (OR, 0.34; 95% CI, 0.18-0.64; P-trend 0.001). Such that, when multiple potential confounders were controlled, the association remained significant in the full adjustment model (OR, 0.28; 95% CI, 0.10-0.76; P-trend 0.001). CONCLUSIONS: The finding indicates a significant inverse association between DTAC and the risk of RA, suggesting that promoting a naturally elevated antioxidant capacity might help prevent the development of RA. Further prospective studies are required to confirm these findings.