The interest in, and consumption of medicinal mushrooms in North America, has increased enormously in the past decade. With each new study and finding, the excitement continues to build. As companies vie for market share, the truth about these important natural products can be stretched, sometimes beyond scientific credibility. This article will attempt to separate fact from fiction by looking at what some human clinical trials reveal; and explore the semi-truths and myths that are part of the “nature is better” viewpoint. 

As a professional herbalist and assistant professor in family medicine I often observe this disconnect. I have limited time for extremists on both ends of the spectrum; both those who believe supplements have poor quality control, and those who believe everything natural is safe. The key word is belief, as this suggests rational thinking has been avoided at all cost. 

Myth 1. All edible, fresh medicinal mushrooms in food stores are healthy. FALSE. 

Alas, some commercial mushroom growers have not converted to organic production. The use of fungicides, until the past decade, was industry standard, as optimal growing conditions for production of mushrooms are the same for disease-causing fungi. Always look for organic products and let your local grocer know your preference. I am extremely wary of the dried mushrooms coming from China. Dried shiitake, in particular, unless it specifies organic, is not found in my kitchen. Heavy metals are country-wide problems for all foodstuffs from some countries. 

Another concern is documented mis-identification of mushrooms in the market and in restaurants. Gyromitras instead of morels, and Catathelasmas sold as matsutake, are two examples noted in the marketplace.

Myth 2. Medicinal mushrooms have no side-effects. FALSE.

There are a number of issues concerning allergies and sensitivity to particular mushrooms. Dermatitis and allergic sensitivity have been noted in some individuals consuming raw or under-cooked cultivated shiitake.

Darkened nails have been noted in some long-term consumers of turkey tail. Morels are of particular concern to individuals of Mediterranean descent. Like favism, and severe anemia associated with ingestion of fava beans, morels will induce this same condition in those genetically predisposed. This syndrome is caused by a deficiency in the enzyme G6PD, and was a response on a genetic level to combat ill effects of malaria.

And of course, almost anyone can develop sensitivity to a particular edible or medicinal mushroom.

Myth 3. All polypores are safe to prepare and use for medicine. FALSE.

The polypore Hapalopilus nidulans may contain up to 40% polyporic acid. Two separate cases in Germany, cited by Michael Beug (2012) found the victims suffered dysregulation of kidneys and central nervous system. Vulpinic acid, found in the yellow wolf lichen, Letharia vulpina, is closely related, highly toxic, and was used to kill wolves by ancient peoples.

Myth 4. Medicinal mushrooms stimulate the immune system. FALSE.

Medicinal mushrooms are immune modulators, meaning they optimize immune function, whether deficient or excessive in nature. In the latter case, various autoimmune conditions such as rheumatoid arthritis, and a vast variety of neuromuscular conditions may benefit from damping down the over-response of cytokine cascade, inflammation, and tissue destruction. Optimizing immune function encourages the various T and B cells to recognize, attack, and destroy foreign cells, including cancer, bacteria, viruses, and even pathogenic fungi.

In order for a substance to be directly cytotoxic, it would have to come in direct contact with the cancer cell and destroy it, without harming surrounding healthy cells. The induction of apoptosis, or cell programmed death, is one of the more important mechanisms by which medicinal mushrooms help fight cancer (Indran et al., 2011; Wong, 2011).

Myth 5. Vitamin C enhances the benefit of many medicinal mushrooms. FALSE.

There are reports of in vitro synergistic effects on bladder cancer cell lines (Konno, 2007). And in many journals, books (including mine), and magazine articles, the promoted use of vitamin C with medicinal mushrooms purports to increase efficacy, absorption or reduction of side effects. There is no scientific evidence that confirms this long held belief. That is, vitamin C is not produced by humans and it may have an additive effect with mushrooms, but not synergistic and expediential.

A recent study by Sayin et al. (2014) suggests that synthetic antioxidants, may interfere with p53 and exacerbate cancer tumor cell lines, at least in mice. The inactivation of p53 is significant as acceleration of tumor growth by artificial antioxidants may reduce the efficacy of reishi and other mushrooms that optimize p53. Maybe. (A recent book by Sue Armstrong [2015] looks at the amazing p53 gene.)

And nearly all vitamin C in health food stores is produced from corn (so those with allergies should be aware); nearly all vitamin D on market is synthesized from sheep wool lanolin (vegans beware!) except that obtained from mushrooms.

Myth 6. Fruiting bodies and mycelium have the same medicinal benefit. FALSE.

The fruiting body of a mushroom is part of the reproductive strategy of the organism, similar to production of an apple by a tree. No one would suggest that the apple tree leaves or bark has similar health benefits to the fruit, and yet the commercial world of medicinal mushrooms does not always differentiate. The myco-chemistry of mycelium and fruiting bodies may well have synergy, and share some compounds in common, but to say they are the same is blatantly false. It is theorized that conks contain more plant sterols, because it has to modulate the tree’s “immune system,” allowing the organism to fruit through the bark without triggering the tree’s immune (hypersensitive) response. For example, Ganoderma conk (wild) has higher levels of triterpenoids, while cultivated Ganoderma mycelium may have increased beta glucans. Similarly, Reishi fruiting bodies contain triterpenoids lacking in mycelium powders. Traditionally, only fruiting bodies were used for food and medicine.

Myth 7. Wild-crafted fruiting bodies are superior to factory-produced products. FALSE.

Alas, there is no real proof either way. As a bioregional herbalist who loves to pick his own plants and mushrooms for medicine, I have my own bias and beliefs. But there is little evidence that Cordyceps produced artificially is inferior or superior to wild-crafted Tibetan product. What is true is that the average person cannot afford the latter, whereas well-produced cultivated products allow all of us to enjoy the health benefits.

Reishi cultivation is highly sophisticated and commercially-produced products can be very efficacious. This does not mean I will stop making my own extracts of Ganoderma, Trametes, and Fomitopsis species. I enjoy the hunt, the preparation and the love that goes into home produced products.

Myth 8. A high ORAC measurement means one medicinal mushroom is superior to another. FALSE.

The Oxygen Radical Absorbent Capacity test measures free oxygen radical absorption. High phenolics do this well. Mass media marketing suggests chaga has an ORAC score of 36,557 compared to blueberries at just 24.5. This “information” is then used to convince consumers that chaga is vastly superior to the tasty fruit. Chaga is an important medicinal mushroom, no doubt about it. But we cannot compare apples and oranges—or blueberries and mushrooms!

The USDA recently removed its ORAC database from its NDL website due to “mounting evidence that the values indicating anti-oxidant capacity have no relevance to the effects of specific bioactive compounds.” And remember, the all-important polysaccharide content of medicinal mushrooms is not measured by this scale.

Myth 9. The substrate source of cellulose does not influence the constituents of the mycelium or fruiting bodies. FALSE.

The nature and quality of the substrate can greatly influence both mycelium and fruiting body growth, and yield. Commercial companies are most interested in production yield. Dollar for dollar, the most expensive mushroom products on the market are grain substrate mycelium.

Undigested grain mycelium contains a high level of inactive linear polysaccharides. These are quite different from the non-linear branched beta-glucans that have been shown to modulate immune response.

My background as an herbalist leads to an interest in utilizing medicinal plants as part of the substrate and then searching for novel compounds produced by the mushrooms. Oyster mushrooms, for example, can be grown on newspapers (soy ink only), grapevines, Astragalus, Job’s tears, pea vines, soy, corn cobs etc. The significance of novel compounds, by growing medicinal mushrooms on a variety of substrates, has yet to be fully explored. Like any commodity crop, the herbal industry has significant tonnage of waste product that may well yield valuable, novel compounds for human health.

The Colorado-based company MycoTechnology has developed a way to grow reishi mushrooms on coffee beans. The immune modulating beta-glucans are found in the coffee beans, called ReishiSmooth. They have also developed a strain of Cordyceps that thrives on coffee and chocolate.

Myth 10. Medicinal mushrooms can be taken safely with chemotherapy or pharmaceutical drugs in general. FALSE.

Many medicinal mushrooms can be used as adjunct therapy with chemotherapy or radiation treatments. In fact, one of the great areas of success with medicinal mushrooms is the amelioration of side effects and optimizing immune function during toxic biomedical treatment.

Some medicinal mushrooms can interact with or change dosage of various pharmaceutical and over the counter medications.

Reishi, for example, should not be used before surgery due to its vasodilating effect. Women suffering heavy menstruation may wish to stop reishi during their period. Patients taking ACE inhibitors should proceed with caution. Wood ear mushroom (Auricularia spp.) thins blood and should not be used with patients taking warfarin, Coumadin, and other blood thinners. On the other hand, Cordyceps has been found to ameliorate the nephrotoxicity associated with cyclosporine, an anti-rejection drug used with organ transplant patients (Bao et al., 1999).

Myth 11. Never eat any raw mushrooms. FALSE.

There are a number of mushrooms that contain toxins destroyed by heat, including the common Agaricus species (including button, crimini, and portobello). The content of agaritine, is reduced by cooking but some does remain. Morels should be cooked. The woody polypores require decocting, or boiling, to release the medicinal polysaccharides from their tough chitinous cells.

On the other hand, I doubt I have tasted anything better than raw Boletus “edulis” from the hills around Telluride, Colorado. A drizzle of olive oil, pinch of salt and … all I can say is wow!

The verdict on enoki (Flammulina velutipes) is not certain. I throw them into a hot soup near the end of cooking, but no longer spread them on salads. They are probably not only safe, but may help reduce cancers, as the center of enoki production in Nagano, Japan showed the lowest rate of various cancers based on an epidemiological study done over twenty five years ago (Ikekawa et al., 1989).

Myth 12. Modern extraction methods are superior to traditional methods. YES AND NO.

The traditional method of boiling polypores such as reishi produces excellent results. Some alcohol appears to increase availability of other compounds with health benefits, including possibly more antiviral activity. The use of wine tonics in traditional Chinese medicine suggests that water and alcohol may play a role. There is great controversy over hot or cold water extraction, to the point where I am not sure where science ends and marketing begins. As all scientists say when applying for grants, “more research is needed.” Chitin is extremely difficult to break down, so heat may be beneficial as medicinal properties are not destroyed by heat.

Myth 13. All medicinal mushrooms are edible. FALSE.

The fruiting body of nearly all medicinal mushrooms are woody, tough, and difficult to eat or digest. I read in one book that young Piptoporus betulinus conks were delicious. So I found some small, young specimens, sliced them up and sautéed. The texture was like eating pencil erasers, and the taste was butter and garlic.

The reverse is true. Most edible mushrooms are medicinal, maybe all of them.

Myth 14. Because some mushrooms hyper-accumulate heavy metals from the soil, they can help remove heavy metals from the human body. FALSE.

Mushrooms can contribute valuable macro- and microminerals to our diet, including chromium, vanadium, and selenium. In fact, ongoing research will lead to availability of trace mineral-enriched edible mushrooms in your local grocery store.

But the underlying assumption that edible and medicinal mushroom draw heavy metals from the body is not proven by science. It may well be true, but I cannot find one paper that has studied before and after chelation therapies using mushrooms.

Pectins, including modified citrus pectins, various green vegetables such as kale, parsley and cilantro, as well as onions and garlic can be helpful. The most important compound, glutathione, is produced by the body from three amino acids. It is so important that 7% of the energy produced by our body is used to create this important detoxifier. Heavy metals stored in fatty tissue have to become water soluble in order to be removed from the body, and involve Phase One and then rapid Phase Two stages of liver involvement.

Myth 15. Alcohol and medicinal mushrooms should not be taken together. FALSE.

This is true if you consider alcohol inky caps, Coprinopsis atramentarius, as well as a few other mushrooms considered to be medicinal. Research suggests Coprinus comatus may be useful in prostate and breast cancers, various drug-resistant bacteria, blood sugar dysregulation, etc. (Rogers, 2011). Their rapid deliquescence makes the mushrooms difficult to preserve.

Myth 16. Any high percentage alcohol may be used to produce high quality medicinal mushroom tinctures. FALSE.

Several years ago I began to question the use of a popular 190 proof corn-based alcohol for herbal and mushroom tinctures. Because it is derived from GMO corn I choose to no longer buy or use it. Alchemical Solutions of Oregon produces superior organic alcohols from corn, wheat, grape, and sugarcane. Some medicinal mushroom experts claim alcohol denatures chitin, causing crystallization and hardening of the cross-linked makeup of this complex. 

Myth 17. Capsules of medicinal mushrooms are not as potent or efficacious as tinctures or other extraction methods. FALSE. 

The final product and the format in which it is offered does not decide the quality. It is up to the consumer to read the labels carefully and note the variables including ratio of extract, the percentage of fruiting body to mycelium, the substrate used, and do some homework about the company. There are products on the market that are simply powdered fruiting bodies that have locked-up polysaccharide content which cannot be used by the human body. 

Myth 18. Companies selling medicinal mushroom products on the internet use GMP or good manufacturing practices. FALSE. 

Are you kidding me? I recently saw a website from my home province that was selling turkey tail tincture. I was curious so emailed the site and questioned if the product was locally sourced, knowing that turkey tail is hardly found in Alberta. The reply was yes, so I asked for a picture. They sent me a Trametes or Stereum photograph, but certainly not Trametes versicolor. I politely asked them to stop selling fraudulent products to consumers and never heard from them again. Consumer beware! 

Myth 19. Standardized extracts are a guarantee of a high quality medicinal mushroom product. FALSE. 

As in herbal medicine, the various standardized markers associated with medicinal mushrooms vary widely. The use of cordycepic acid as a marker for Cordyceps efficacy, is useless, according to Paul Stamets and John Holliday. 

Other examples include a wide array of markers for chaga, reishi, and turkey tail which may or may not identify the medicinal component. In fact, when dealing with isolated compounds, one runs into the same pharmaceutical mindset that separates holistic herbalists from the health professionals with green coats. If a product is standardized to a percentage of this or that, it often means that something has been removed. 

References Cited

Armstrong, S. 2015. P53: The Gene That Cracked the Cancer Code. Bloomsbury Publishing New York, USA. 

Bao, Z.D. et al. 1999. Chung Kuo Chung His I Chieh Ho Tsa Chih. 14(5): 271-273. 

Beug, M. 2012. Polyporic acid in fungi: a brief note. McIlvainea 21. 

Ikekawa, T., N. Uehara, Y. Maeda, M. Nakanishi, and F. Fukuoka. 1989. Twenty-years of studies on antitumor activities of mushrooms. Cancer Research 29: 734-735. 

Indran, I.R., G. Tufo, S. Prevaiz, and C. Brenner. 2011. Recent advances in apoptosis, mitochondria and drug resistance in cancer cells. Biochemica et Biophysica Acta 1807(6): 735-745. 

Konno, S. 2007. Effects of various natural products on growth of bladder cancer cells: two promising mushroom extracts. Alternative Medicine Review 12(1): 63-68. 

Rogers, R. 2011. The Fungal Pharmacy: The Complete Guide to Medicinal Mushrooms and Lichens of North America. North Atlantic Books, Berkeley, CA. 

Sayin, V.I., M.X. Ibrahim, E. Larsson, J.A. Nilsson, P. Lindahl, and M.O. Bergo. 2014. Antioxidants accelerate lung cancer progression in mice. Science Translational Medicine 6: 221. 

Wong, R.S.Y. 2011. Apoptosis in cancer: from pathogenesis to treatment. Journal of Experimental & Clinical Cancer Research. 30: 87-101.

Posted with permission from FUNGI Vol 82



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