Research conducted in the US and China has identified that regular consumption of green tea may reduce a woman's risk of breast cancer by about 12 per cent.
The scientists report that the reduction was observed for regular tea drinkers, compared to non-drinkers, after evaluating the diet of 3454 women with breast cancer and 3474 healthy controls aged between 20 and 74. Furthermore, benefits for pre-menopausal women were related to the number of years they had been regular drinkers, and a dose-response was also observed.
Green tea contains between 30 and 40 per cent of water-extractable polyphenols, while black tea (green tea that has been oxidized by fermentation) contains between 3 and 10 per cent. Oolong tea is semi-fermented tea and is somewhere between green and black tea.
In addition to the potential anti-cancer benefits, previous studies have reported a range of health benefits for green tea and its extracts, including the potential to promote weight loss, and protection against Alzheimer's.