This study examined the association between the intake of green tea, a natural source of polyphenols, and the risk of breast cancer in Japanese-American women. It included 119 participants before and 72 participants after menopause. All women were free of disease. The scientists found that estrogen and estradiol, two factors in the development of breast cancer, were approximately 20% and 40% lower in postmenopausal women drinking green tea daily, as compared to those drinking green tea less than at least once a week. It was thus suggested that intake of green tea can influence breast cancer risk. For more details, please see the study.
Barbara J Fuhrman, Ruth M Pfeiffer, Anna H Wu, Xia Xu, Larry K Keefer, Timothy D Veenstra, Regina G Ziegler