We also studied serum concentrations of lipid peroxides in relation to consumption of green tea. It has been suggested that lipid peroxidation was involved in the process of oxidative DNA damage and cytotoxicity as well as in that of arteriosclerosis.25 26 Our data on the same cohort population of men showed that serum concentrations of lipid peroxides among current smokers (n=850) were higher (9.0 (SE 0.1) nmol/ml) than those among non-smokers (n=226) (8.4 (0.2) nmol/ml; P/= 500 was decreased with increased consumption of green tea (8.3 (0.3) nmol/ml among 171 smokers who consumed daily >/= 10 cups; 9.0 (0.2) nmol/ml among 262 smokers who consumed daily 4-9 cups; 9.4 (0.3) nmol/ml among 122 smokers who consumed daily /= 10 cups of green tea a day. Adjustments for age, alcohol consumption, and relative body weight did not affect the association.