Drinking green tea may not protect against breast cancer

Green tea is often touted for its antioxidant properties, but a study finds that drinking the stuff -- even a lot of it -- may not protect against breast cancer.

The study, released this week in the journal Breast Cancer Research, analyzed self-reported data on the green tea drinking habits of 53,793 women in Japan. During 13.6 years of follow-up, 581 cases of breast cancer were diagnosed among the women.

Women’s consumption of green tea varied; at the beginning of the study about 12% drank less than one cup per week and 27% drank five or more cups a day. Researchers found no link between drinking green tea and incidences of breast cancer, regardless of how much they drank, their menopausal stage, or the type of tea they consumed.

One of the study’s strengths, said lead author Motoko Iwasaki of the National Cancer Center in Tokyo, via a news release, is that it followed women over time, “…in which information was collected before the subsequent diagnosis of breast cancer, thereby avoiding the exposure recall bias inherent to case-control studies. Drinking green tea as a beverage is unlikely to reduce the risk of breast cancer regardless of green tea type and number of cups.”