Aims: To investigate the effects of factors including dietary habits, lifestyle, anthropometric characteristics, plasma lipid profiles, and antioxidants on DNA damage among the Korean population. Methods: Blood samples were collected from 109 healthy Korean volunteers, aged 19-28 years, of whom 34% were smokers. Epidemiological information was collected by personal interviews, and anthropometric characteristics were measured directly. Oxidative DNA damage was quantified using the Comet assay; tail length (TL) and tail moment (TM) were measured. Results: Statistically significant (p < 0.05) positive correlations were observed between DNA damage (TM or TL) and smoking habits expressed as cigarettes smoked per day and number of packs smoked over time (r = 0.332 and 0.370, respectively, for TM; r = 0.266 and 0.304 for TL, respectively). There were also significant and positive correlations between DNA damage parameters and waist-hip ratio (r = 0.352 for TM and r = 0.226 for TL), but this significance disappeared after data were adjusted to account for smoking effects. Higher plasma triglyceride levels were associated with increased damage to DNA (r = 0.234 for TM and r = 0.271 for TL). Conclusions: Our results indicate that cigarette smoking and high plasma triglyceride levels significantly increase DNA damage to peripheral lymphocytes in a sample of Koreans. Copyright (C) 2004 S. Karger AG, Basel.