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Over the last several months, there has been considerable debate between growers of medicinal mushrooms regarding the proper growing, identification and testing of these health products. As one party has put it, “Medicinal mushrooms are a category that has experienced high growth but few actual quality control standards.” These are not minor issues from the standpoint of health and efficacy or, for that matter, potentially from the standpoint of regulatory bodies. The chief protagonist in these discussions is Jeff Chilton, who has published somewhat detailed and technical articles under the heading of “Commercial Labeling of Medicinal Mushroom Products” (HerbalEGram: Volume 12, Issue 10, October 2015) and as a White Paper entitled Redefining Medicinal Mushrooms (Nammex Organic Mushroom Extracts | A much more accessible paper is available as “10 Questions to ask About Your Mushroom Supplement” ( A response has come from Paul Stamets under the heading Beyond Beta-Glucans: Evolutions in Mushroom Science (October 15, 2015), albeit Stamets’ rejoinder really does more to detour the discussion into additional topics than to refute any one of Chilton’s positions.

The use of mushrooms for health and medicine is a millennial-old practice in China, Tibet and Japan. In a simplified sense, much of the debate between Chilton and Stamets comes down to observations and judgments of traditional medical systems as reflected in science and terminology versus new approaches based on radically altered growing and related practices. Traditionally and in most of the scientific literature, the items loosely termed “mushrooms” actually are divisible into three main components: mycelium, mushroom and spore. These are the different stages of growth and in traditional practices are viewed as typically manifesting quite different qualities when consumed. Likewise, in traditional Chinese medicine (TCM) and related systems, the growth medium and growing conditions are extremely important. Chilton’s general position is that the active component mix is far different for the fruiting body (i.e., the mushroom) than it is for the mycelium and that these fungi manifest very different component mixtures grown on their native mediums (wood, for instance) than grown on grains (corn, rice, etc.).

In fact, Chilton’s observations are borne out all the time with common foodstuffs. Under-ripe fruits, grains and vegetables exhibit quite different properties — not usually desirable, but occasionally advantageous — compared with their ripe versions. Bitter melon is an example of a wonderful food always eaten in its immature stage and never when fully ripe, just as the fully ripe seeds are avoided. Similarly, only dairy products from animals grazing on grass or grass silage yield the valued CLA (conjugated linoleic acid) and also more of a variety of other nutrients. Hence, common observations in areas other than mushroom growing tend to support Chilton’s general positions.

Is the Product from Fruiting Body (Mushroom) or Mycelium?
According to FDA regulations, a dietary supplement is required to provide identification of ingredients, including the part of the plant or other source used. In practice this means, for example, that reishi extracts should give the common name (reishi), the Latin identification (Ganoderma lucidum) and the part used (mycelium, fruiting body/mushroom, and/or spore). If a portion of the product consists of other material(s), such as remnants of the growth medium, these must be listed under “other ingredients.”

There are many good reasons for this regulation and these are clear in the case of mushroom powders and extracts. Once more taking reishi as the example, it is well established that a number of the compounds valued in traditional usage are found primarily or in greater quantities in the fruiting body. Such compounds include ganoderans and various triterpenes (119 or more are known, including ganoderic and ganoderenic acids). Adenosine and Ling Zhi-8 protein are found in both. These are compounds that modulate the effects of the extract to such an extent that in Chinese medical terms the “mushroom” or “fruiting body” is considered to be either “neutral” or even “cool,” hence although reishi is a powerful immunostimulant, it remains balanced and anti-inflammatory whereas mycelium extracts are considered to be “warm” or even “hot,” meaning potentially inflammatory and sensitizing. Spore extracts, likewise, are very immunoactive, meaning, again, that they will not lead to the same results as are expected from extracts of the fruiting body. There can be reasons for using the spores, but the purchaser should be aware of the implications inasmuch as spores/spore extracts do not have either the history of medicinal use or the body of research true of the mycelia and fruiting bodies.

Mycelium products usually are very inexpensive compared to the mushroom fruiting body and therefore commercially it is tempting to obscure the distinction between the two. The FDA, by the way, plainly states that mycelium products cannot be listed as mushroom, i.e., fruiting body. The FDA’s position on this issue is found in Compliance Policy Guide, Section 585.525

The Medium Is Important
Chilton refers to grain-grown mycelium as mycelium on grain (MOG). The mycelium in these products is not separated from the grain, so residual grain becomes a dominant feature of the MOG products. Of course, the mycelium has medicinal properties and much research demonstrates this fact. The contentious issues include the degree to which MOG is composed of grain and the differences between the mycelium and the fruiting body of a given species.

In his papers and at the Nammex website, Chilton supplies test data demonstrating that the concentrations of one or more important components, such as the particular beta-D-glucans that are prized from mushrooms, generally are very different between the grain-grown mycelium and the fruiting bodies. Similarly, the mixtures of the various compounds are different. Grown on traditional substrates or media, mushrooms produce triterpenes and other compounds that either are not seen or are found in much reduced amounts with grain-grown products. The reason for growing mycelium on grain, of course, is that it is very inexpensive compared to native growing mediums such as characterize mushrooms in their natural environment.

Powder or Extract?
Those who have looked at textbooks of traditional Chinese herbal prescriptions will know that dosages typically run into many grams of the raw materials that then are boiled in water to produce decoctions for drinking. Sometimes water-alcohol mixtures are used to extract compounds not readily watersoluble, sometimes herbs are fried in oils or charred, and so forth and so on. Relatively few herbs are consumed in their simple powdered states and those that are usually must be consumed in large quantities.

In practice, this means that extraction is necessary to concentrate the range of available active ingredients in amounts and in forms that can readily be ingested and absorbed. One obvious reason for extractions is greater bioavailability. For reishi, properly prepared extracts must include triterpenoids as well as the beta-D-glucan fractions. As Chilton notes, grains supply glucan fractions that may be, for instance, simply starch. Other glucan fractions can be fibers, such as the well-known glucan found in oat fiber. Supplement Facts panels should make clear that it is the active compounds that are being tested and listed. Vague terms such as polysaccharide are not useful. Merriam-Webster defines polysaccharide as “a carbohydrate that can be decomposed by hydrolysis into two or more molecules of monosaccharides; especially: one (as cellulose, starch, or glycogen) containing many monosaccharide units…” Better products often will make clear the extraction solvents, as well, e.g., water or water-alcohol.

Other Issues
Inasmuch as mycelium-based products will generally contain a fraction of the material used as the medium, if GMO grains are used, the end product will most likely contain GMO grain fractions and, quite possibly, the glyphosate or other compounds used to raise the grain. Such contaminations are extremely common in foodstuffs — recently, a test of a large number of beers made and sold in Germany found that every single one contained trace or more amounts of glyphosate with one containing 30 micrograms per liter.1 Unfortunately, wording indicating “combination” products and “full spectrum” products can confuse purchasers as to the amount of grain residues that remain. With mushrooms, as with most other foodstuffs, organic is best.

Those interested in the topic of medicinal mushrooms might want to spend time with the literature and websites listed at the beginning of this article.2 For medicinal mushrooms, as is often the case with other products, reliable information can be hard to come by. Nevertheless, self-education with regard to medicinal mushrooms may be even more important than with most other dietary supplements and herbs.


  1. “Glyphosate weed killer found in German beers.”
  2. See Chapter 9 Ganoderma lucidum (Lingzhi or Reishi) in Benzie IFF, Wachtel-Galor S, editors. Herbal Medicine: Biomolecular and Clinical Aspects. 2nd edition. Boca Raton (FL): CRC Press/Taylor & Francis; 2011.

Dallas Clouatre, PhD

Dallas Clouatre, Ph.D. earned his A.B. from Stanford and his Ph.D. from the University of California at Berkeley. A Fellow of the American College of Nutrition, he is a prominent industry consultant in the US, Europe, and Asia, and is a sought-after speaker and spokesperson. He is the author of numerous books. Recent publications include "Tocotrienols in Vitamin E: Hype or Science?" and "Vitamin E – Natural vs. Synthetic" in Tocotrienols: Vitamin E Beyond Tocopherols (2008), "Grape Seed Extract" in the Encyclopedia Of Dietary Supplements (2005), "Kava Kava: Examining New Reports of Toxicity" in Toxicology Letters (2004) and Anti-Fat Nutrients (4th edition).