on plasma antioxidant capacity and a number of risk factors in patients with coronary artery disease. While some human intervention studies evaluating effects of tea consumption on selective biomarkers of oxidative stress have been confronted with certain confounding lifestyle factors, this study was designed to minimize effects of smoking and alcohol on levels of the measured biomarkers. It is impossible for all subjects to maintain the same food consumption throughout the study period. The subjects were asked to maintain their former diet during the study and it was expected that the randomized design could balance eventual bias between the study and control groups. Nevertheless their daily diet was monitored and diet form data indicated that the fat/lipid content of the population diet did not change significantly during the intervention trial.