In a study carried out in China and published in the International Journal of Cancer researchers concluded that women who consume at least a third of an ounce of fresh mushrooms every day were 64% less likely to develop breast cancer. Dried mushrooms were not as effective as fresh but reduced the risk by about 50%. In addition, women who combined mushrooms with regular consumption of green tea reduced their risk by about 90%. The researchers cautioned that the findings do not prove eating mushrooms stop cancer and more studies are needed. However, animal studies have also shown that fungi have anti-tumor properties and also stimulate the immune system.
Further research is ongoing. For example, scientist at the U of California are studying the effect of taking mushroom extract in helping breast cancer survivors remain free of cancer.