Plasma total antioxidant capacity reflects plasma antioxidant status in overweight postmenopausal women

Increased plasma total antioxidant capacity (TAC) is associated with intake of fruits and vegetables. However, there is limited information available on the association of plasma TAC with individual endogenous and exogenous antioxidant components in plasma. This study assessed plasma TAC by two different assays to evaluate its predictability for plasma antioxidant status. Forty postmenopausal, overweight, and apparently healthy women were recruited. Seven‐day diet recalls and 12‐h fasting blood samples were collected for dietary and plasma antioxidant assessments. Plasma TAC was determined by ABTS and ORAC assays. TAC values from ABTS assay were significantly correlated with those from ORAC assay (r=0.34). After multivariate adjustment, plasma TAC determined by ABTS was positively associated with plasma total phenolics (p<0.05), α‐tocopherol (p<0.001), and uric acid (p<0.01); was marginally associated with β‐carotene (p=0.06), β‐cryptoxanthin (p=0.09), and SOD (p=0.08). Pearson correlation results showed total phenolics, uric acid and albumin were significantly correlated with vitamin‐C equivalent antioxidant capacity (VCEAC) (p<0.05). The findings indicate that plasma TAC reflects antioxidant status in vivo. Grant Funding Source : Donaghue Nutrition Research Program