DNA damage in lymphocytes of elderly patients in relation with total antioxidant levels.

DNA damage may occur as a result of an imbalance between the production and removal of free radicals, a process in which age plays an outstanding role. The purpose of this study was to analyze the relationship between total antioxidants and DNA damage in a sample of old age people in Mexico City. The sample included a total of 88 subjects, 15 males and 69 females, with a mean age of 65.5 years old (range between 60 and 79 years old), all of whom had lived in Mexico City during the last 10 years and had been diagnosed as clinically healthy. Results showed that 52% of the subjects presented DNA damage in peripheral blood lymphocytes which was assessed through an alkaline unicellular electrophoresis procedure (Comet Test), regardless of total antioxidant serum levels quantified through a colorimetric method (Randox Kit). Higher non-damage occurrences were observed in subjects with low antioxidant levels, a difference that was statistically significant (P < 0.05). Furthermore, the highest incidence of damaged cells was observed in subjects belonging to the 70-years-old-and-above group (P < 0.05). As to the magnitude and intensity of the damage associated to total antioxidant concentrations, a trend toward greater DNA damage in subjects with low serum levels was observed. It is concluded that low antioxidant levels are not always indicative of oxidative strain and therefore should not be considered as predictors of DNA damage in this population.