March 2021 Issue

Medicinal Mushrooms — An Exploration of Their Purported Health Benefits in the Form of Powders and Liquid Extracts
By Carrie Dennett, MPH, RDN, CD
Today’s Dietitian
Vol. 23, No. 3, P. 20

Are mushroom powders in drinks and elixirs healthful or overhyped?

Mushrooms have been enjoying a place in the limelight for several years thanks to their nutrition, taste, and textural attributes. While their rich umami flavor and chewy texture make them an appealing meat substitute, their superfood status is increasingly driving a different market segment, one focused on using mushroom extracts to optimize health and prevent disease. Today, it’s easy to find teas, coffees, powdered lemonade mixes, protein shakes, and pills containing powdered and liquid extracts of mushrooms that promise to reduce stress or boost energy levels. Mushroom latte, anyone?

Because some people don’t appreciate the unfamiliar shapes and spongy textures of medicinal mushrooms—and may not know how to prepare them—mushroom extracts certainly can be an appealing way to reap purported health benefits, and the dietary supplement industry has jumped on board. Traditionally, most of the mushroom extract market share has been in capsules and tablets—which have a longer shelf life and are convenient to use—followed by powders and then liquids, but consumer interest in ready-to-drink tea may shift this trend.1,2 Many mushroom beverage manufacturers are going to great lengths to create products that disguise the presence of fungi by incorporating strong and familiar flavors such as coffee, cocoa, and matcha.

What’s Driving the Trend?
Mushrooms have been used in Eastern medicine for about 3,000 years. Now they’re being marketed in the West as “functional” or “medicinal” mushrooms. Growth is being driven by consumer interest in health and disease prevention, particularly in using food as medicine—foods that offer nutrition plus additional health benefits.3,4 Depending on the source and parameters of the market research, the global market is expected to grow 6% to 7% per year and be worth as much as $68 billion by 2026.1,5

A recent shift also has occurred in consumer priorities.6 “There’s currently increased interest in functional foods and especially foods and supplements that can potentially support the immune system,” says Seattle-based clinical dietitian Ginger Hultin, MS, RDN, CSO, a spokesperson for the Academy of Nutrition and Dietetics and owner of Champagne Nutrition, LLC. “Clients are often attracted to foods that have the potential to help them meet their health goals without the use of medications, so with all the marketing about how mushrooms can help reduce blood pressure, [improve] blood sugar, stoke the immune system, or even aid in cognitive support, people feel that it’s a fairly safe option that could have big payoffs.”

Originally used to treat infections, medicinal mushrooms recently have been used to help treat pulmonary diseases and cancer. In Japan and China, they’ve been approved adjuncts to standard cancer treatment for more than 30 years.7

However, while cancer and disease prevention are oft-touted claims, the trend in using mushroom extracts in beverages is more aligned with the broader adaptogen trend,8 as evidenced by the leader-of-the-pack status of reishi mushrooms, which are showing up in many adaptogenic herbal blends.9

Adaptogens are substances purported to help the body “adapt” to stress.10 While many adaptogens are herbs, mushrooms—especially reishi, cordyceps, maitake, and shitake—are classified as adaptogens in both traditional Chinese medicine and Ayurveda. Products using mushroom extracts and other adaptogens also have gained traction among “wellness” influencers and celebrities.11

“A lot of people claim that these mushrooms can improve mood, provide energy, improve brain function, and even fight off tumors and cancer, largely thanks to their alleged adaptogenic properties,” says Toronto-based dietitian Abbey Sharp, RD, who blogs and posts videos at Abbey’s Kitchen. “I definitely think it’s really dangerous to assume any of these supplements can ‘fight cancer,’ as it may encourage people to forgo lifesaving conventional medicine and treatment.”

Bioactive Compounds
Mushrooms contain vitamins, minerals, and antioxidants, including ergothioneine, an amino acid derived from histidine,12 as well as selenium, vitamin C, choline, and a small amount of vitamin D. They’re also rich in B vitamins. However, nutrition isn’t the basis for most of the health claims associated with mushroom extracts. Rather, the focus is on other bioactive compounds, which in some cases are extracted and used in their “pure” form. These include the following:

Beta-glucans are a soluble fiber also found in oats and barley that may support healthy immune function and blood glucose levels, and they have anti-inflammatory, antioxidant, antibiotic, antiviral, and cholesterol-lowering effects.13,14

Triterpenoids, a group of phytochemicals that have antioxidant and anti-inflammatory properties and may protect the liver, lower cholesterol, inhibit histamine release, and help prevent and treat cancer.15,16

Ergosterol, a precursor to vitamin D2, has purported antitumor and antioxidant properties.17

It’s important to note that different parts of the same fungi may contain varying levels of active compounds.18,19 Teas and supplements made from the “mushroom” itself—the fungal organism’s fruiting bodies or reproductive structure, encompassed by the cap and stem—aren’t the same as those made from the mycelium. Also known as the vegetative body, the mycelium is the filamentous web that makes up the majority of the fungal organism, growing embedded in the wood, soil, grain, or other growth medium. Mushroom extracts made from fruiting bodies generally are considered to be higher quality, offering a greater concentration of potentially beneficial compounds.19

The FDA states that mushroom mycelium (which is a misnomer, because the mushroom and the mycelium are two different parts of the fungal organism) are suitable for food use when grown in acceptable media, but that products should be labeled to clearly indicate that they contain mycelium.20 A 2019 guidance policy by the American Herbal Products Association allows for using the word “mushroom” on product labels but states that the particular fungi parts should be listed in the ingredient panel in order of predominance by weight.21

Health Claims
Mushroom-related beneficial claims for both physical and mental health are numerous, including boosting immunity and reducing anxiety,22,23 which can be appealing in the wake of the chaotic and difficult 2020. However, while in vitro research on mushrooms suggests numerous promising benefits, including killing cancer in human cells and reducing insulin resistance,24 evidence in humans is much scarcer.25 Looking at what human research does exist, it’s hard to draw conclusions about how these extracts would impact a broad range of people because the studies have been small and targeted to specific populations. The following is a snapshot of some of the major health claims for specific medicinal mushrooms:

Chaga (Inonotus obliquus) is claimed to be adaptogenic and contain antioxidant and immune-boosting properties. Despite its use as a “folk remedy” against cancer, a 2015 review by Memorial Sloan Kettering Cancer Center in New York found that no clinical trials had been conducted to assess safety and efficacy for disease prevention or treatment of cancer, CVD, or diabetes.26

Cordyceps is a genus with about 750 identified species—about 35 of which have been shown to contain medicinal properties—that use caterpillars and other larvae as hosts. Natural cordyceps is expensive and hard to get, so most supplements are made with lab-grown cordyceps.27 It’s touted as an energy booster, supposedly upregulating adenosine triphosphate synthesis and oxygen uptake.3 Research suggests cordyceps has anti-inflammatory, antioxidant, and antitumor effects and that it benefits lung, liver, kidney, and immune health as well as helps lower cholesterol.28 Cordyceps also is considered to be an adaptogen.

Lion’s mane (Hericium erinaceus) has been shown to inhibit the growth of human cancer cells and protect against neurodegeneration in in vitro and animal studies.22 It’s often touted as the “smart mushroom.”3

Maitake or hen-of-the-woods (Grifola frondosa) appears to help improve the immune system in some cancer patients and reduce blood glucose levels in rats.24,29 This contributes to general marketing claims that it lowers blood sugar levels and boosts immunity, and is an adaptogen.

Reishi (Ganoderma lucidum) is touted as the “mushroom of immortality” and may have antitumor, antimicrobial, anti-inflammatory, antioxidant, and cholesterol-lowering properties, largely due to its triterpenoids and polysaccharides.16 A 2016 Cochrane review concluded that reishi could be considered an adjunct to conventional cancer treatment, but evidence doesn’t support its use as a first-line treatment, and it’s unclear whether its use contributes to long-term cancer survival.30 Claims also include that it’s adaptogenic and can reduce stress, as well as benefiting cardiovascular health and boosting

Shitake (Lentinula edodes) is a widely consumed mushroom and its extracts may help humans improve their immune system31 and prolong the lives of some cancer patients undergoing chemotherapy.25,32

Turkey tail (Trametes versicolor or Coriolus versicolor) has been used to treat pulmonary diseases in traditional Chinese medicine and used as an adjuvant treatment for cancer since the 1970s.7 Its use in cancer treatment has fueled general claims that it boosts immunity. It’s also considered an adaptogen.

“You’ll always see influencers make over-the-top, sensationalized claims about products, many of which are not advertised by food manufacturers (probably in an effort to avoid a lawsuit),” Sharp says. “But generally speaking, we do see a lot of claims automatically transferred onto food products that are based on small animal studies or test tube studies of a particular ingredient (like reishi mushrooms) in isolation. The truth is that most food products don’t contain anywhere near the dosages used in test tube or animal trials.”

Recommendations for RDs
When counseling patients who have an interest in mushroom teas or products, there are three main considerations: Can the product interact with any medications the patient is taking, is the product high quality, and what does the patient want to achieve with the product?

Helping clients navigate supplement safety is key for any dietary supplement, including mushroom extracts. Hultin emphasizes that “natural” doesn’t mean harmless because even herbs and other dietary supplements, including mushrooms, can interact with other supplements and medications a patient takes. “Some mushrooms have powerful effects that can actually lower blood pressure or blood sugar, so taking into account medical conditions is also important,” she says, adding that the Natural Medicines Database states that reishi mushrooms have moderate interactions with a variety of medications and includes warnings for those with low blood pressure or bleeding disorders.

“It’s also worth noting that most supplements are not well regulated,” Sharp says. “It’s kind of the Wild West out there.” She and Hultin both recommend using products that have third-party testing certifications. That’s important to make sure that the product contains what the label says—and nothing more. Major third-party testers include US Pharmacopeia, NSF International, and

An analysis published in 2017 in Nature Scientific Reports tested 19 batches of reishi supplement products, most of which were sold through Amazon and eBay. Of those, just five products contained some element of reishi.33 Plus, as mentioned, it’s important to know what part of the fungus is in the product. Ideally, the product should state that it’s 100% derived from fruit bodies and identify the amount of beta-glucans it contains—and third-party testing confirms this.

Be wary of the term “full spectrum,” which some companies have adopted for marketing purposes, if a label simply lists well-known mushroom species or lists “myceliated brown rice” or other grains in its ingredient list. Grains often are used as fungal growth mediums, and unfortunately, many companies may be selling products primarily composed of mycelium-on-grain, also called mycelium biomass. That means starch may be the primary ingredient. If the product says it contains mycelium biomass but grain isn’t listed as an ingredient of the biomass, the product could be considered adulterated.18,34

True medicinal mushroom supplements will have a distinct, rich mushroom smell, which could be earthy, musty, or bitter, depending on the mushroom variety, and the mushroom powder should have a dark, rich color. Mycelium products, by contrast, are mildly sweet. If the product is light in color and smells like starch—perhaps with a cereal or crackerlike aroma—this suggests the product is grain based.18,34

“I think a lot of us want to believe that we can just add one of these superfood products into our diet and bam, we will be healthy. But health and wellness is a long game, it’s not something you can cheat,” Sharp says. “I recommend spending that money on nutritious fruits and vegetables, [for] which we have ample evidence to support their benefit.”

Hultin says that while some individual mushrooms and blends of mushrooms could have health benefits, much of the current evidence is from in vitro or animal studies. “It’s important to educate clients that one dietary supplement isn’t the answer to their health issues and that instead, we need to work on getting them medical care and testing to keep them safe; there’s a lot we can do with the overall dietary pattern and other lifestyle factors like sleep and physical activity, rather than leaning on supplements as a ‘cure’ or primary treatment.”

Sharp says glowing online reviews of mushroom products could be due to the placebo effect and recalls spending about $50 on a box of mushroom coffee, only to throw it away after trying it. “It tasted truly horrible and [is] something I would never drink, even if it did have health properties,” she says. “If I wasn’t a critical consumer and hadn’t looked into the research myself, I would have probably felt so compelled to use it up and put a lot of faith in those benefits to ‘get my money’s worth.’”

— Carrie Dennett, MPH, RDN, CD, is the nutrition columnist for The Seattle Times, owner of Nutrition by Carrie, and author of Healthy for Your Life: A Holistic Guide to Optimal Wellness.


1. Global medicinal mushroom extract market: information by type (shiitake, reishi, chaga, maitake, cordyceps, turkey tail and others), form (capsules & tablets, powder and liquid), function (antioxidants, immunity enhancer, skin care and others) and region (North America, Europe, Asia-Pacific and rest of the world) - forecast till 2026. Market Research Future website. Published July 2020.

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