In their quest to find new ways to fight cancer, researchers are increasingly turning to nature. They’re discovering that many of the vegetables we regularly consume in our diet —notably mushrooms—are potent cancer killers. A new study in the journal Nutrition and Cancer finds that the white button mushroom is particularly effective against prostate cancer.
A number of different mushroom species have been investigated for their cancer-fighting properties. “I think mushrooms, and especially medicinal mushrooms, are being used to prevent cancer because they potentially have the ability to affect immune function in our bodies,” says study author Shiuan Chen, PhD, Professor and Director of the Division of Tumor Cell Biology at the Beckman Research Institute of the City of Hope in Duarte, California.
In previous studies, Dr. Chen and his colleagues discovered that the white button mushroom was effective at suppressing the spread of breast cancer cells. For this study, the researchers again focused on the white button mushroom, but this time for its potential effect on prostate cancer cells.
Although it hasn’t been as well studied as medicinal mushrooms, the white button mushroom has the advantage of being edible, which makes it ideal for studying dietary cancer interventions, according to Dr. Chen. White button mushrooms contain a healthy fatty acid called conjugated linoleic acid (CLA), which is believed to be one of the active components responsible for halting cancer cell growth.
During this study, the researchers investigated the effects of a white button mushroom extract on prostate cancer cell lines in the laboratory, and in mice injected with prostate cancer. When prostate cancer cells in the lab were treated with the mushroom extract for a period of four days, the cancer spread was markedly reduced compared to untreated cells, and an increased number of cancer cells died. The higher the dose of mushroom extract, the greater the effect on the cancer cells. The mushroom extract appeared to work equally well on both hormone-dependent and hormone-independent prostate cancers.
When mice with prostate cancer were fed the mushroom extract, their tumors shrank by as much as 68 percent compared to the control mice. The extract also significantly slowed the cancer spread and triggered the process of programmed cancer cell death (apoptosis). The researchers discovered that CLA helped inhibit the spread of cancer cells, but Dr. Chen says other active substances in the mushroom were also likely involved in its biological activity.
Now that a strong anti-cancer effect has been noted in the laboratory and in mice, the next step is to test out white button mushrooms in human clinical trials. Human studies have begun at City of Hope, according to Dr. Chen. Participants are prostate cancer patients who have not responded to surgery, hormone therapy, or other standard treatments. The studies will try to determine whether the mushroom extract can slow the rise of prostate-specific antigen (PSA)—a marker of prostate cancer growth—and pinpoint the most effective dosage.
Although Dr. Chen cautions that this research is still preliminary, and dietary interventions should never take the place of standard prostate cancer treatments, he says this study adds to the growing evidence that adding white button mushrooms to the diet may help protect men against prostate cancer.
Adams LS, Phung S, Wu X, Ki L, Chen S. White button mushroom (Agaricus Bisporus) exhibits antiproliferative and propapoptopic properties and inhibits prostate tumor growth in athymic mice. Nutrition and Cancer. 2008;60:744-756.