Impact of apple and grape juice consumption on the antioxidant status in healthy subjects.

It is reported that consumption of antioxidant-rich foods significantly increased plasma total antioxidant capacity (T-AOC) in humans. Also, it is proved that the antioxidants from plant foods improve the body's antioxidant defence by acting additively and synergistically. As a result, rational combination of antioxidant-rich foods is recommended to population in the prevention of oxidative stress-related diseases. Both apple and grape are antioxidant-rich fruits. In this study, 2 weeks dietary intervention study was carried out in 25 healthy subjects to investigate the influences of apple and grape juices consumption on body antioxidant status. Our results indicated that 2 weeks of apple and grape juice consumption increased the plasma T-AOC and decreased the concentration of malondialdehyde. However, no change was found in the content of plasma carbonyl. Erythrocyte glutathione peroxidase and catalase activities were enhanced by 2 weeks of fruit juice consumption; however, no change was found in the activity of erythrocyte superoxide dismutase. The in vitro comet assay results indicated that apple and grape juice consumption did not influence lymphocyte damage upon hydrogen peroxide treatment. Urinary 8-hydroxy-2-deoxyguanosine content was not affected by 2 weeks of fruit juice intervention. These findings indicated that concomitant intake of apple and grape juice was efficient in enhancing the body's antioxidant status.