AGING AND CIGARETTE-SMOKING ARE ASSOCIATED WITH DECREASED GLUTATHIONELEVELS IN HUMANS

The relationships between age, smoking status and plasma glutathione l evels were investigated in 90 current, asymptomatic, male cigarette sm okers and in 75 non-smoking, matched control subjects. Relative to non -smokers, the plasma glutathione levels of smokers were decreased by a n average 23% (P < 0.0001). plasma levels of this anti-oxidant were al so considerably lower in both smokers and non-smokers aged 35 years an d over The mean decrease in plasma glutathione of non-smokers aged > 3 5 years was 48% (P < 0.0001), the corresponding decrease being 39% (P < 0.0064) in smokers. These observations demonstrate that ageing in pa rticular, as well as cigarette smoking, have pronounced effects on pla sma glutathione levels in humans.