A Medicinal Mushroom Warning (Cordyceps Sinensis)…Buyer Beware!

…The data are conflicting.

Some studies report immune-stimulating effects, while others report immune-suppressing activity of Cordyceps sinensis.

How Is This Possible?

One hypothesis is that different strains of Cordyceps sinensis can either suppress or stimulate the immune system. In fact, one strain of Cordyceps sinensis strains was reported to be as potent of an immune-suppressant as the powerful drug, Cyclosporin A (commonly used to inhibit the immune system from rejecting a transplanted organ.)

Another hypothesis for the varying results of these studies is that specific extracts of Cordyceps sinensis may be more potent  (i.e. strong immune suppressing or stimulating activity) depending on the extraction methods used in preparing the Cordyceps sinensis product. Interestingly, in June 2012, the U.S. Patent Office issued a patent to use Cordyceps sinensis extracts as immune-suppressing agents.

Two of the most concerning complications that can happen after being on immune-suppressing drugs are the increased risk of infections and cancer.

If the wrong strain (or extract) of Cordyceps sinensis is inadvertently used, a patient with an already compromised immune system or a history of cancer could be doing themselves more harm than good!

You still may not be safe even if you use a Cordyceps sinensis product that claims to contain an immune-stimulating strain, such as the widely studied Paecilomyces hepiali strain (also known as “CS-4’); CS-4 has been shown to have immune-stimulating effects in numerous studies. However…some Cordyceps Sinensis products contain more than one strain (see study.) If two strains are present, one strain being immune-stimulating (e.g. CS-4) and the other strain being immune-suppressing, the overall effect on the immune system is uncertain. In the best-case scenario, the immune-stimulating strain will outweigh the immune-suppressing activity of the other strain; the overall effect will likely be less immune stimulating than if you had been taking a pure immune-stimulating strain.

So, how do you find out what strain is in each Cordyceps sinensis product?

Unfortunately, many of the manufacturers currently do not indicate the strain(s) of Cordyceps sinensis on their packaging! Furthermore, the U.S. Food and Drug Administration does not monitor supplements for their quality control. Quality control is left up to the individual manufacturers to ensure that all strains are identified, and potency and consistency is maintained between each batch.

The Bottomline: My recommendation is to, at a bare minimum, select a Cordyceps sinensis product from a manufacturer that clearly indicates the strain type(s) used in their supplement.

• I highly recommend the Host Defense brand since their Cordyceps sinensis strain is pure CS-4 (immune-stimulating); this is per personal communication with founder and mycologist, Paul Stamets.

Read more about the potential anti-cancer benefits of medicinal mushrooms on our blog.