Green tea and cancer

Abstract

Despite being one of the most widely consumed beverages in the world, green tea is often seen by the media as a so-called superfood, attributed with various health benefits including protective effects against cancer. This reputation rests primarily on the fact that green tea is a rich source of polyphenols, which provide much of the colour and aroma of tea. Both green and black varieties are aqueous infusions of the plant Camellia sinensis, but whereas the constituent polyphenols of black tea are allowed to become oxidised to theaflavins during processing, green tea leaves are heat-treated to inactivate their polyphenol oxidase activity, enabling the native catechins to remain intact.