Lifestyle predictors of oxidant and antioxidant enzyme activities and total antioxidant capacity in healthy women: a cross-sectional study.

The aim of this study was to identify demographic and modifiable lifestyle factors that may be related to endogenous oxidant and antioxidant activity measured in blood specimens from putatively healthy women recruited at the Roswell Park Cancer Institute (Buffalo, NY, USA). Total glutathione (TGSH), catalase (CAT), CuZn-superoxide dismutase (CuZn-SOD), glutathione peroxidase (GPx), glutathione reductase (GR), and myeloperoxidase (MPO) activity, and total antioxidant capacity (TAC) were measured in 124 healthy women, and associations with epidemiological factors were tested using general linear models. There were significant differences in oxidant and antioxidant enzyme activities according to lifestyle factors, after adjusting for duration of blood storage and season of blood draw. Compared to women who consumed ≤2.8 servings of fruits and vegetables daily, those consuming >5.3 servings had on average 31 % lower MPO activity (p-trend = 0.02), as a marker of oxidative stress, 16 % higher antioxidant GPx activity (p-trend = 0.08), and 9 % higher TAC (p-trend = 0.05). Obese women (body mass index, BMI ≥ 30) in contrast showed 17 % lower antioxidant GPx activity, 44 % higher MPO activity (p-trend = 0.03), and 10 % higher TAC (p-trend = 0.03) compared to women with normal BMI < 25. Smoking was associated with higher TGSH activity (p-trend = 0.01) and lower TAC (p-trend = 0.05). Higher TAC levels were most strongly associated with increasing age (standardized β = 0.40, p < 0.0001), BMI (standardized β = 0.17, p = 0.03), and GPx activity (standardized β = 0.23, p = 0.005), and inversely associated with CuZn-SOD activity (standardized β = -0.14, p = 0.07). Physical activity levels, multivitamin use, and alcohol intake were not associated with TAC. Our data indicate that endogenous oxidant and antioxidant enzyme activities are associated with lifestyle factors and, therefore, may be potentially modifiable, with implications for risk reduction of chronic conditions related to oxidative stress.