Zhang M, Huang J, Xie X, Holman CD. Dietary intakes of mushrooms and green tea combine to reduce the risk of breast cancer in Chinese women. Int J Cancer. 2009;124(6): 1404-1408.
To investigate effects of dietary mushrooms and joint effects of mushrooms and green tea on breast cancer, a case-control study was conducted in southeast China in 2004-2005. The study included 1,009 female patients ages 20 to 87 years with confirmed breast cancer and an equal number of healthy women similar in age. Information on frequency and quantity of dietary intake of mushrooms and tea consumption, usual diet, and lifestyle were collected during face-to-face interviews using a validated questionnaire. Compared with nonconsumers, the odds ratios (ORs) were 0.36 (95% CI = 0.25 to 0.51) and 0.53 (0.38 to 0.73) for those whose daily intake was 10 grams or more of fresh mushrooms and 4 grams or more of dried mushrooms. Compared with those who consumed neither mushrooms nor green tea, the ORs were 0.11 (0.06 to 0.20) and 0.18 (0.11 to 0.29) for daily high intake of fresh and dried mushrooms combined with consuming beverages made from 1.05 grams dried green tea leaves or more per day. The study concluded that higher dietary intake of mushrooms decreased breast cancer risk in pre- and postmenopausal Chinese women and an additional decreased risk of breast cancer from a joint effect of mushrooms and green tea was observed. More research is warranted to examine the effects of dietary mushrooms and the mechanism of joint effects of phytochemicals on breast cancer.