A common ingredient in many Chinese stir fry dishes is also a potentially powerful cancer fighter, according to a recent study published in the International Journal of Oncology. Researchers have discovered that the oyster mushroom can significantly inhibit the growth of colon and breast cancer cells without harming healthy cells.
Past studies have found that mushrooms have a number of therapeutic benefits, including promoting the immune system and preventing cancer development. Several research efforts have already looked at the effects of various inedible medicinal mushroom extracts on cancer cells.
For the current study, researchers wanted to focus on edible mushrooms. Because these mushrooms are available in any grocery store, they might one day play an important role in cancer prevention, according to lead author Daniel Sliva, PhD, Senior Investigator in the Cancer Research Laboratory at Methodist Research Institute in Indianapolis. The oyster mushroom is one of the most common edible mushrooms in the world, and it has been found to have both antioxidant and antitumor properties.
When Dr. Sliva tested an extract from this mushroom on two of the most common and deadly cancers — breast and colon cancer — the oyster mushroom halted the growth of even the most invasive cancers. The higher the dose and the longer the mushroom extract was applied, the greater the effect on cancer cells.
The researchers discovered that the oyster mushroom extract works by interfering with the cancer cell cycle. By stopping this cycle at a specific phase, the mushroom prevents the cancer cells from spreading, says Dr. Sliva. It also alters the size and shape of the cancer cells, which prevents them from growing and pushes them to a type of programmed cell death called apoptosis. Another of its effects is to decrease the production of certain proteins, which are abnormally over-expressed by cancer cells. “With the mushrooms we can actually modulate this microenvironment in cells so that these cancer cells can behave like normal cells,” says Dr. Sliva.
While the oyster mushroom attacks cancer cells, it spares healthy cells because it targets cellular mechanisms that are specific to cancer. “I think that this mushroom contains some special molecules, which are able to attack signaling pathways that are over-activated specifically in cancer cells,” Dr. Sliva says. “In normal cells those pathways are not over-activated.”
Because oyster mushrooms are all natural, they can be taken in relatively high doses without triggering unwanted side effects—a clear advantage over many current cancer therapies.
Laboratory studies done so far with the oyster mushroom have been very promising, and the results of animal studies are set to be released in the near future. The next step is to try out the mushroom extract in human clinical trials. “If we can show an effect at the molecular level and confirm it in animal studies, this would really be a help to human health,” Dr. Sliva says.
If you are interested in using mushrooms for any health reason you should speak to your licensed healthcare practitioner.
Jedinak A, Sliva D. Pleurotus ostreatus inhibits proliferation of human breast and colon cancer cells through p53-dependent as well as p53-independent pathway. International Journal of Oncology. 2008;33:1307-1313.