Reuters Health Information
Green Tea Appears to Protect Against Breast Cancer
 

NEW YORK (Reuters Health) Sept 02 - Among Asian-American women, consumption of green tea is associated with a reduced risk of breast cancer, according to a report in the September 10th issue of the International Journal of Cancer.

In a population-based, case-control study, Dr. Anna H. Wu, of the University of Southern California, Los Angeles, and colleagues examined the consumption of green tea among 501 Asian-American women with breast cancer and 594 matched controls. The investigators also collected data on menstrual and reproductive factors, dietary habits, and other lifestyle factors.

There was no association between consumption of black tea and the risk of breast cancer. Green tea, however, was associated with a significant reduction of breast cancer risk. This association was maintained after adjustments for age, specific Asian ethnicity, birthplace, age at menarche, parity, menopausal status, use of hormones, body size, and intake of total calories.

"Compared to women who did not drink tea (either black or green) regularly (i.e., less than once a month), risk of breast cancer was lowest among those who drank green tea only (odds ratio = 0.57), intermediate among those who drank both green and black tea (odds ratio = 0.69), and unchanged among those who drank black tea only (odds ratio = 1.00) after adjustment for the covariates mentioned above," Dr. Wu and colleagues report.

The inverse relationship between breast cancer risk and green tea consumption remained significant after adjusting for smoking; intake of alcohol, coffee, black tea, soy, and dark green vegetables; family history of breast cancer; and physical activity, according to the investigators.

Both green tea and soy intake were significantly and independently protective against breast cancer. However, the beneficial effect of green tea was primarily observed among those who consumed low levels of soy, and the beneficial effect of soy were primarily observed among those who did not drink green tea.

"In conclusion, our study shows that green tea may act as a chemopreventive agent against breast cancer development," the researchers write.

Int J Cancer 2003;106:574-579.