Antioxidant supplementation reduces inter-individual variation in markers of oxidative damage

The aim of this study was to examine the effect of antioxidant supplementation on oxidative damage and chromosome stability in middle-aged men, smokers and non-smokers. A total of 124 men aged 48+/-6 years from Bratislava and from the rural population near Bratislava were investigated; 64 men (22 smokers and 42 non-smokers) were supplemented for 12 weeks with antioxidants, while 60 (25 smokers and 35 non-smokers) were given placebo. The daily antioxidant supplementation consisted of vitamin C (100 mg), vitamin E (100 mg), ss-carotene (6 mg), and selenium (50 microg). Samples of blood were taken on two occasions: At the beginning and at the end of the supplementation trial. Concentrations of dietary antioxidants, ferric reducing ability, malondialdehyde as an indicator of lipid peroxidation in plasma, micronuclei and chromosome aberrations in lymphocytes were measured. Antioxidant supplementation significantly increased the levels of vitamin C, ss-carotene, a-tocopherol and selenium in plasma. The overall antioxidant status of plasma measured as ferric reducing ability of plasma (FRAP) increased significantly (p<0.001) after antioxidant supplementation as well. The increase in antioxidant parameters after supplementation were consistently more pronounced in non-smokers than in smokers. There was a significant decrease of malondialdehyde concentration in the non-smokers, while in smokers the decrease of malondialdehyde concentration was not significant. Antioxidant supplementation did not affect the proportion of lymphocytes with micronuclei or the total number of micronuclei; however, there was a significant positive correlation (p<0.001) between the malondialdehyde concentration at the beginning of the supplementation trial and the difference in number of cells with micronuclei before and after the supplementation. The percent of cells with chromosome aberrations decreased significantly after antioxidant supplementation in smokers. These results indicate that a combined antioxidant supplementation (a) is effective even at very moderate doses; (b) significantly diminishes oxidative damage to lipids when it is high initially; and (c) is effective in decreasing chromosomal instability in lymphocytes of middle-aged men.