RESUMO
Tea has been consumed worldwide since ancient times to maintain and improve health. Its main active components are a type of polyphenols known as flavonoids, which include catechins and theaflavins. Several epidemiological studies suggest that the consumption of green tea could prevent cancer development in humans. Likewise, animal studies have shown that green tea consumption may inhibit the development of prostate and breast cancer. It has been shown that, through several mechanisms, tea polyphenols present antioxidant and anticarcinogenic activities, thus affording several health benefits. It is important to better characterize tea components, to study their bio-availability and bio-transformation in vivo and to conduct clinical studies of its main active compounds.