Inadequate antioxidant nutrient intake and altered plasma antioxidant status of rheumatoid arthritis patients

Objective: Elevated free radical generation in inflamed joints and impaired antioxidant system have been implicated in rheumatoid arthritis (RA). The present study was performed to evaluate dietary nutrient intake and plasma oxidant/antioxidant status in RA patients. Methods: RA patients (n = 97) and their age, gender-matched controls (n = 97) participated in this cross-sectional case-control study. Nutrient intake was estimated using a semi-quantitative food frequency questionnaire. Twenty subjects from each group provided blood samples, and plasma concentrations of a-tocopherol and malondiadehyde (MDA) were measured. Also, plasma activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx) were measured. Results: The mean calorie intake of RA patients was lower than that of the healthy controls. Energy-adjusted intake of fat, vitamin A and beta-carotene were significantly lower in patients than those of the control subjects. RA patients had a decreased mean plasma alpha-tocopherol level. The activity of plasma SOD and GPx in patients was significantly lower than that in control subjects. Conclusion: These results suggest proper antioxidant nutrient intake management may reduce free radical generation and improve antioxidant status in RA patients.