Background and objective: It has been proposed that women have an estrogen activity-linked biological antioxidant advantage and that this advantage is lost in the postmenopausal stage. The latter remains controversial. Our aim was to determine age-related sex differences in oxidative stress and oxidative DNA damage in a healthy Mexican population.
Methods: A cross-sectional and comparative study was carried out in a convenience sample of 162 healthy subjects aged as follows: (1) 25-44 years (n = 35 women and 38 men), (2) 45-64 years (n = 41 women and 27 men), and (3) >or=65 years (n = 13 women and 8 men). We measured plasma lipoperoxides (LPO), superoxide dismutase (SOD), glutathione peroxidase (GPx), and DNA damage by comet assay.
Results: We found greater activity of GPx in women than in men according to age increase (p < 0.05). This activity is maintained in old age in women. In contrast, men exhibited a significant diminution in GPx according to age increase. Similarly, we observed a greater percentage of cells without oxidative DNA damage in women in the 45-64-years age group and in the group of women aged >or=65 years.
Conclusions: Our findings suggest that women have a more efficient antioxidant activity than men, which has been linked with the greater longevity observed in women.