Attenuation of DNA damage with green tea consumption in active smokers. A, comparison between active smokers not taking- and those who were using one or two cups of green tea every day. The length of DNA comet was greatly decreased in active smokers who were using green tea. B, quantitative analysis of DNA damage in different levels of active smokers and those who were using green tea. The analysis showed that green tea significantly reduced the TCS values or DNA damage in class 4 compared to active smokers with no usage of green tea on daily basis.