Dietary and serum antioxidant capacity is inversely associated with patients in osteoarthritis: a case-control study

This study aimed to examine dietary antioxidant and serum antioxidant capacity in patients with knee osteoarthritis (OA). This case-control study consisted of 47 patients with OA (case group) and 30 healthy subjects (control group). The control and case group were matched age, gender, and body mass index (p > 0.05). A food frequency questionnaire was administered to participants, and dietary total antioxidant capacity (DTAC) was estimated using the ferric reducing antioxidant power method (FRAP). Participants' serum total antioxidant capacity (TAC) and total oxidant capacity (TOC) measurements were performed, and the oxidative stress index (OSI) was calculated. DTAC of case group was found to be lower than the control group (p < 0.05). The daily consumption of red meat and butter of the individuals in the case group was higher than that of the control group, and their fish consumption, dietary vitamin A and carotene intakes were found to be lower (p < 0.05). In addition, OA patients have TAC and OSI was also found to be significantly higher than in control group (p = 0.001 and p < 0.001). Since low dietary total antioxidant capacity and high serum total oxidant capacity, individuals with OA should pay more attention to their diet to increase serum antioxidant status.