Revista de Nutrição e Ciências Alimentares
Acesso livre

Abstrato

Modulation of Oxidative Damage by Green and Black Tea: Role of Smoking and Gender in a Randomized Trial

Hakim IA, Garland L, Harris R, Cordova CA, Mikhael DM and Chow HHS

Background: Oxidative stress has been implicated as an important modulator of human health and can play a role in both disease prevention and disease development. Objectives: The overall goal of this study was to determine the effects of high tea consumption on biological markers of oxidative stress that mediate lung cancer risk, including, 8-hydroxydeoxy-guanosine (8-OHdG) and F2-isoprostanes (8-iso-PGF2α). Design: We completed a 6-month randomized, controlled, double-blinded trial in a group of former and current smokers who were randomized to receive green or black tea preparations or a matching placebo.

Results: A total of 146 participants (80 females and 66 males) completed the study. At the end of the 6-month intervention, female smokers in the green tea group showed a 35% decrease (p=0.04) in DNA damage while female former smokers in the black tea group showed a 26% decrease (p=0.015) in lipid damage. No significant changes in markers of oxidative stress were observed in men.

Conclusion: This data confirm our previous findings related to the beneficial effect of green tea on oxidative DNA damage among female smokers. The significant beneficial effect of black tea on oxidative lipid damage as well as the gender difference merit further studies.