Erythrocyte Zn concentration and antioxidant response after supplementation with Zn in a postmenopausal population. A double-blind randomized trial

Abstract

Background & aims: Menopausal hormonal changes increase the risk of deficiencies of minerals such as zinc (Zn), which could further worsen the decreased antioxidant defense of postmenopausal women. This study assesses the effect of 8 weeks of Zn supplementation upon the antioxidant status and clinical nutritional parameters of a postmenopausal population. Methods: Fifty-one postmenopausal women were divided into two groups: placebo (PbG) and zinc supplementation (ZnG). Mineral status was determined by Flame Atomic Absorption Spectrophotometry (FAAS). Total Antioxidant Capacity (TAC) and Superoxide Dismutase (SOD) were analyzed by kinetic colorimetric methods. Glutathione Peroxidase (GPx) was assessed by an enzymatic immunological method. Results: Poor Zn status was initially observed in erythrocyte samples. Total antioxidant capacity showed a significant correlation (r = 0.730; p < 0.05) to erythrocyte Zn after the intervention (ZnG: r = 0.96; p < 0.001). Moreover, erythrocyte Zn concentration in ZnG was positively correlated to GPx activity after the intervention (r = 0.61; p < 0.01). Conclusions: The postmenopausal women initially presented Zn deficiency, and the status of this mineral improved after the intervention. Zinc supplementation may be an effective approach for correcting the observed deficiencies, enhancing antioxidant defense in this risk population.