Objectives: To compare the effects of lotus root and cucumber on antioxidant function in aged subjects.
Design: Pilot comparative study.
Setting: Research setting with vegetable intervention.
Participants: Healthy aged subjects over the age of sixty.
Intervention: 30-day supplementation of lotus root or cucumber powder.
Measurements: Plasma value of ferric reducing antioxidant power assay, activity of antioxidant enzymes, contents of some antioxidants, oxidation products, hemolysis, blood mononuclear cell DNA damage and urinary excretion of 8-hydroxy-2'-deoxyguanosine were measured before and after the intervention.
Results: Plasma glutathione peroxidase activity, contents of vitamin C, total phenolics were significantly increased, while plasma uric acid content significantly decreased in both groups at the end of the intervention. Meanwhile, hemolysis was significantly reduced in both groups and DNA injury rate of blood mononuclear cells in lotus root group and the ratio of comet tail length to total length in cucumber group were also declined significantly post-intervention. However, plasma value of ferric reducing antioxidant power assay, contents of reduced glutathione, vitamin E, malondialdehyde, oxidized low density lipoprotein, carbonyls and activity of superoxide dismutase and catalase were not changed significantly in both group after the intervention.
Conclusion: These results suggest that lotus root and cucumber are not remarkably different in improving antioxidant function in aged subjects, though they are significantly different in antioxidant capacity in vitro. The benefits observed in this study may come from the additive or synergistic combinations of antioxidants contained in vegetables.