An essential guide to Medicinal Mushrooms

 Of an estimated 2.2 to 3.8 million species of fungi on Earth, only about 4 percent have been documented and described.

The interactions between fungi and humans are ancient — fungi have been around for about 1 billion years, according to a recent discovery based on fossils collected in northern Canada by an international team of researchers. The previous estimate was about 460 million years. This research shows that fungi appeared on land prior to the evolution of flowering plants, prior to the rise of insects, and long before the evolution of mammals. Other research shows that our distant ancestors were interacting with fungi. It’s no wonder, then, that we have developed sensors throughout our bodies to detect the presence of fungi.

Since then, the scientific research and publication on the myriad ways fungi interact with our immune system and other body systems, as well as their disease-preventing and healing properties, have grown tremendously. Currently, the published scientific literature on turkey tail fungus alone is likely to rival all the combined literature that existed in 1985 on all species of fungi used for medicine by all world cultures. In 1985, about 70 studies were published based on the keywords “medicinal mushrooms” in the scientific literature. By 2019, that had grown to about 4,400.

Turkey Tail Mushroom

Fungi are medicinal because they affect our nutrition, metabolism, and immunity. Mushrooms and fungi could activate many aspects of our immune response, whose fundamental purpose is to protect us from pathogenic types of viruses and bacteria.

What causes disease? Why does it come to some people who seem perfectly healthy, despite their best efforts to take care of themselves in a good way? Is good health just the absence of disease, or something greater?

-Christopher Hobbs

According to traditional Chinese medicine, disease-promoting factors are created in our bodies through our constitution, diet, and metabolism, as well as external influences from the environment like hot, cold, dry, and damp. To the ancients, fungi like reishi could help remove these pathogens and restore healthy balance throughout our body’s systems, enabling us to maintain homeostasis.

THE HEALING POTENTIAL OF FUNGI

I want to share the amazing story of how fungi interact with our body to activate global immune responses, help calm our nervous system, benefit our cardiovascular system, and protect us from toxins and stresses in our environment, all the while supplying important nutrients. The healing potential of fungi is promising indeed.

Hippocrates is thought to have said, “Let your food be your medicine and your medicine be your food.” This statement is more relevant than ever, now that modern science has found so many active and healing compounds in common foods like curcumin in turmeric and curry, allicin in garlic, quercetin in apples and onions, and the cancer-preventive compounds in brassica vegetables like broccoli and kale called Se-methylselenocysteine and glucosinolates.

High in Minerals, B Vitamins, and Protein

When it comes to nutrition, mushrooms have so much to offer! They are a rich source of vitamins, and they have an incredibly high mineral content (some types have 7 to 12 percent total minerals); they are a particularly good source of trace minerals such as zinc, copper, and iron, as well as the macrominerals phosphorus and potassium. Mushrooms also have a significant amount of all the B-complex vitamins (including B12) — almost as much as meat. Since B12 is a crucial vitamin for our body to create new, healthy blood cells, and meat is the highest and most bioavailable source, vegetarians can become deficient in this important nutrient. Cooking mushrooms helps break down cell walls and render the minerals more bioavailable. Heat can destroy some of the vitamins, but stir-frying mushrooms like oyster mushrooms and shiitakes with a ­little water will ­preserve a good portion of the B vitamins.

Fungi are also an excellent source of high-­quality protein; some oyster mushrooms, for example, contain up to 30 percent protein. This makes mushrooms a valuable addition to the diet, especially in parts of the world where protein is scarce; fungi can efficiently convert plant waste into a sustainable form of protein that humans can digest and assimilate efficiently. The protein in mushrooms contains all nine essential amino acids.

THE HIGHEST FIBER FOOD

Not only are mushrooms high in fiber, they have the highest dietary fiber content of any food, on a dry-weight basis. (Most fresh mushrooms contain up to 95 percent water.) Dietary fiber comprises several types of sugar polymers — in mushrooms, this includes beta-glucans and chitin. These polymers aren’t digestible in the upper digestive tract, so they travel almost intact to the lower bowel, where bacteria degrade them as prebiotics. These support an environment where beneficial ­bacteria are encouraged and potentially harmful bacteria are suppressed. In this way, when consumed regularly, mushrooms can help us maintain an optimal microbial balance for health.

Mushrooms Support Good Gut Microbes

Scientists are discovering just how important the presence of certain beneficial microbial species is for overall health, mood, immunity, and even longevity.1 Research has shown that eating a high-fiber diet is the single most important way to prevent a range of cardiovascular-­related diseases and concerns — including blood cholesterol imbalance, heart attack, stroke, and atherosclerosis (the damage to our vessels that progresses as we age, including “hardening of the arteries” due to plaque buildup) — in addition to reducing the risk of colon cancer, preventing diabetes, and simply keeping bowel movements regular.

In fact, the research shows that many of our modern health problems stem from the fact that we don’t get enough fiber in our diets. People in most industrialized countries consume around 15 grams of fiber per day, whereas people in nonindustrialized countries who eat a traditional diet — one that contains almost no processed food, only moderate amounts of animal products, and lots of roots, leaves, nuts, seeds, whole fruit, grains, and beans — consume closer to 50 or 60 grams of fiber daily. Several studies have shown that people who eat that much fiber lower their risk of cardiovascular disease and cancer by one-half to three-quarters, compared to those who get only 15 grams of fiber per day. (For more details about and to get a better understanding of the benefits of mushroom fiber for health, I recommend reading the article by Peter Cheung from the Chinese University of Hong Kong).

Mushrooms like shiitake contain up to 35 percent total dietary fiber, and some polypores like reishi or fu ling contain up to 85 percent.

A DAILY DIET THAT’S HIGH IN FIBER

To achieve a goal of consuming 40 to 50 grams of fiber a day, you obviously need to eat lots of vegetables, whole grains, beans, and other high-fiber foods. Mushrooms can really boost the total amount of fiber you take in. Here are some foods — including mushrooms! — that can get you up over 50 grams of fiber.

• 1 cup raw oats, soaked (museli, oatmeal) / 8 g
• 1 medium banana / 3 g
• 1 cup cooked broccoli / 3.6 g
• 3 medium shiitake mushrooms in soup or stir-fry / 7 g
• 1 cup cooked beans (lentils, split peas, red kidney beans, or others) / 16 g
• 1⁄2 cup cooked whole grains (buckwheat, brown rice, or others) / about 3 g
• 2–3 cups salad (with mixed vegetables: medium tomato, medium carrot, 1⁄4 onion, lettuce) / 3 g
• 1 cup dark veggies (carrots, beets, ­collard greens) / 4 g
• 1 ounce nuts, seeds (small ­handful) / about 3 g
• 1 medium yam, baked / 4 g
• 1 medium apple or 1⁄2 cup berries / 4 g

SOLUBLE AND INSOLUBLE FIBER

When you simmer turkey tails and blend them up to dry for powder, you will see a lot of gel ­separate out in the water. This gel contains soluble fibers — both the valuable immune-­stimulating beta-glucans and the non-starch alpha-glucans. These soluble fibers reduce inflammation in your digestive track as they pass through, reducing the risk of bowel cancer and promoting cholesterol balance.

For the full benefit of fiber, you need both soluble and insoluble fiber. Other parts of the cell wall in cooked mushrooms, as well as the concentrated mushroom powders, are mostly insoluble fiber. The insoluble fiber can give your digestion something to work with to help remove waste products and stimulate peristalsis, helping to keep you regular. This is why it is best to consume the cooked mushrooms along with the cooking water, rather than filtering the cooked mushrooms out of the cooking water and just using the liquid as a tea.

Achieving Your Dietary Goals with Mushrooms

Because mushrooms can be consumed in a variety of preparations, they are easy to add to meals to help you achieve your dietary goals. Here are just some of the ways to get your daily dose of fungi.

POWDER. An easy way to get more fiber into your diet and reap the other nutritional and immune-boosting benefits of mushrooms is to powder them. The process of making the powder releases the beta-­glucans from other polymers like chitin, much improving their water solubility and bioavailability. You can cook mushrooms, dry them, and make a powder to sprinkle savory mushroom flavor, minerals, protein, and fiber on any food or to add to smoothies or soups. Making a tea from just one rounded teaspoon of dried, powdered mushroom, such as shiitake, adds more than 5 grams of fiber to your daily diet. Other good mushrooms for concentrated tea powder include maitake, lion’s mane, and even a nonbitter species of reishi such as Ganoderma lingzhi.

STIR-FRY. Tender species like shiitake, lion’s mane, and oyster mushrooms can be stir-fried. I usually add 1⁄4 cup of water to a tablespoon of oil in the skillet, to avoid overheating the oil and to steam-cook everything without scorching; add a bit more water later, if the mushrooms start drying out. You won’t need additional water if you’re cooking fresh mushrooms that are very wet or that have been harvested during rainy weather. Always cook the mushrooms before adding any vegetables because the mushrooms often need higher heat and longer cooking. I like to add cooked lentils and a variety of herbs — including garlic, curry powder, oregano, thyme, sage, savory, and parsley — to the stir-fried mushrooms and vegetables to make a delicious soup. Stir-fried mushrooms are also perfect for adding to an omelet.

GRILL. Grilling is a good option for firm mushrooms like milky caps or members of the genus Russula. Brush the caps with or soak them in a sauce made from tamari, a little olive oil or toasted sesame oil, and ­seasonings like crushed garlic, ginger, and curry powder, then grill until tender.

PRESSURE-COOK. I often use my multi­cooker/pressure cooker for tenderizing polypores like turkey tails and other tough fruiting bodies. This reduces the cooking time, as well. An additional benefit is that pressure cooking increases the bioavailability of certain medicinal compounds. Use the high setting on the multi­cooker for up to 60 minutes, depending on how tender the mushrooms are. Tough fruiting bodies like artist’s conk need 60 minutes, but tender ones like lion’s mane can be done in 30. After cooling, blend the well-cooked fruiting bodies with the cooking water. Add 1⁄4 to 1⁄2 cup of this purée to soups for a mushroomy flavor and the benefits of the abundant fiber and immune-activating beta-glucans.

MAKE DUXELLES. This is a well-chopped mixture of mushrooms, onions, and herbs like oregano, parsley, or pepper that is sautéed in olive oil or butter until cooked. For extra protein, I add two beaten eggs once the mushrooms are cooked, then turn off the stove, cover the pan, and let the eggs set in the residual heat. You can use the more tender medicinal mushrooms — such as shiitake, maitake, oyster mushrooms, clamshells, or beech mushrooms — in this fashion.

FUNGAL BETA-GLUCANS AND THEIR BENEFITS

In addition to contributing to our overall health, some of the components that make up the fiber in fungi help modulate the immune system. These components, called immunomodulators, are found in the cell walls of all fungi. Specifically, the fiber in the cell walls of all fungi is partly composed of glucans, which are long chains of glucose molecules (and a type of polysaccharide) that are often indigestible to humans. (Starch is also a polysaccharide, but the way the glucose units are attached to one another allows our body to easily break them down and obtain glucose for energy, either utilizing it immediately or storing it as glycogen or fat.) There are two major types of glucans — alpha-glucans and beta-­glucans — so-called because of how their attached glucose units are oriented.

Research over the last few decades, and especially in the past 5 to 10 years, has clearly shown the significant effect fungal beta-­glucans have on the immune system — for cancer treatment; to increase our resistance to viral, bacterial, and even fungal infections; and for restoration of damaged bone marrow, where immune stem cells that can replenish and “reboot” our immune system are produced. A tremendous worldwide research effort has demonstrated that fungal beta-glucans work as an immunomodulating agent through the activation of innate immune cells such as macrophages, dendritic cells, granulocytes, and natural killer cells. Once our immune system is activated by fungal beta-glucans, adaptive responses are triggered through key immune “effector” cells (such as CD4+ or CD8+ T cells and B cells). These patrol the blood and tissues, sense potential pathogens and waste products like dead cells, and respond by producing immunologically active chemicals such as cytokines, resulting in the inhibition of tumor growth and metastasis or destruction of pathogens like viruses and bacteria.

BOLSTERING IMMUNITY AFFECTS ALL OUR SYSTEMS

One reason reishi has been known throughout history as an important medicine for calming the spirit, soothing our nervous system, and acting as a sleep aid may have to do with its complex effects on our immune system. When our immunity has been weakened by constant stress, poor sleep quality, lack of important nutrients due to poor diet, and chronic infections, this can affect our mood, energy, vitality, and ability to heal. The intimate connection between our immune, hormonal, nervous, and digestive systems is well known.3 The beta-glucans in medicinal mushrooms can have a profound effect on our health; they can help restore the balance and healthy functioning of our systems, fostering better sleep and a more balanced mood.

Heating to Release the Active Compounds

In order to access the active compounds in fungal cell walls, we must heat mushrooms before consuming them.

BETA-GLUCANS. Beta-glucans in the cell walls of mushrooms are tightly bound with a tough amino-glucose polymer called chitin (which is also found in crustacean and insect shells). These bonds need to be broken by high heat to make the beta-­glucans more soluble and bioavailable as they pass through our digestive tract, where they interact with specialized immune tissues and are engulfed by big immune cells called macrophages.4 Only about 20 percent of the beta-glucans are soluble without significant heating. When mushrooms or mushroom powders are heated — steamed, simmered, or boiled — some of the chitin-glucan bonds will break, making them more water soluble and bioavailable in the gut. On the other hand, when the bonds remain connected after regular cooking — for instance, giving shiitake mushrooms a quick stir-fry — they remain intact through the upper digestive tract (where they can still interact with some immune sensors). In this form, the bonds can make it all the way to the lower intestines nearly intact, where abundant species of bacteria can break them down for food (prebiotics). The bacterial metabolic products, especially those of beneficial bacteria species, can benefit us as well; the epithelial cells that line the lower gut can utilize some of the ­sugars that are released as food and energy.

OTHER ACTIVE COMPONENTS. Beta-glucans are not the only type of immunologically active polymer found in the cell walls of fungi that needs to be heated to become more bioavailable. The beta-glucans are by far the most studied of the bioactive cell wall molecules, but other active compounds, such as non-starch alpha-glucans, chitin, and proteins, can also interact with our immune system and need to be heated in order to become fully available to us.

Finally, some mushrooms contain indole compounds like serotonin, melatonin, and 5-hydroxytryptamine (a precursor to melatonin), which also need heat treatment to become fully available. Chanterelles, in particular, contain a high amount of them. Mushrooms with these active compounds might be useful for counteracting sleeping problems and mood disorders (though more research on humans is needed).

In some species, beta-glucans in cell walls form structures like the triple helix, adding strength and flexibility in mushrooms like turkey tail and reishi. Some research has shown that beta-glucans in the triple helix form, in addition to boosting a species’ ability to penetrate tough wood, have enhanced immune-activating properties.

Beta-Glucans Vary by Species

Beta-glucans are found in all fungi, including yeasts. Some species of edible and medici­nal fungi have much more of these active compounds than others do. Not surprisingly, the species of fungi that have been most revered for two to three thousand years also have the highest content of beta-glucans. These include the popular mushrooms reishi and turkey tail.

The type of active beta-glucans varies from one species to the next. More than 270 recognized species of mushrooms have been studied and are known to have specific immunotherapeutic properties; these species all have different types of active beta-­glucans and other compounds.9 The beta-glucans in their cell walls have different configurations and different branching patterns. Based on these differences, the protective effects of each fungal species can be slightly different, or even widely different.

THE ANTIOXIDANT POTENTIAL OF MUSHROOMS

Cell wall polymers like beta-glucans, some special alpha-glucans,10 chitin, and proteins aren’t the only active compounds associ­ated with health benefits in fungi. Other active compounds in fungi that are less studied for their health benefits are smaller, low-­molecular-weight compounds. The two most-studied compounds in fungi are terpenes and phenolic compounds. These are common in both plants and fungi, and a number of phenolic compounds in edible fungi have been studied for their antioxidant and anti-inflammatory properties. Much more research is needed, but fortunately, most of the terpenes and phenolic compounds seem to have beneficial properties and low toxicity.

SUNLIGHT BOOSTS VITAMIN D

All mushrooms contain ergosterol, a cell wall component that, when exposed to sunlight, partially converts to vitamin D2. Studies show that eating mushrooms after exposing them to sunlight 30 to 60 minutes can raise your blood serum vitamin D levels. Only the part of the fruiting body that is exposed to light will have increased levels; slicing mushrooms before laying them out in the sun can increase the levels of vitamin D by up to 10 times.

Terpenes and Phenolic Compounds

Terpenes are a large and ancient group of hydrocarbons — compounds that contain carbon and hydrogen backbones and are found in most living things. Terpene hydrocarbons often form six-membered rings, with a set number of carbons: 10 (monoterpenes), 15 (sesquiterpenes), 20 (diterpenes), and 30 (triterpenes). For example, the essential oils found in plants like lavender, mint, and cannabis — aromatic compounds that confer anti-inflammatory, muscle-­relaxing, nerve-stimulating, and antibacterial effects — are mostly made up of mono­terpenes and sesquiterpenes.

DITERPENES AND TRITERPENES.

These are important and well-studied active compounds in lion’s mane, reishi, and other fungi. Diterpenes in lion’s mane are associated with nerve-regenerative effects.

There are over 300 triterpenes in reishi-­like mushrooms, many of which have been named and studied, including ganoderic acid, ganoderenic acids, ganoderols, and lucideric acid. Significant research into these compounds shows many potentially beneficial biological activities such as anticancer, antiviral, anti-inflammatory, antioxidant, liver-protective, antiobesity, blood-sugar-­regulating, and antimicrobial effects.

PHENOLIC COMPOUNDS.

These compounds, which include flavonoids, phenolic acids, and polyphenols like tannins, are produced in many plants and fungi and are considered protective. Some studies show they have antiaging effects. Elagic acid (also found in pomegranate) and caffeic acid, which are both found in the beefsteak fungus (Fistulina hepatica), had a strong antioxidant and free-radical-lowering effect in laboratory studies using both human and animal cell cultures.

LOOK FOR TRITERPENES ON THE LABEL

This group of compounds is highly talked about when reishi-like fungal products are considered, especially when it comes to the quality of the extract and biological activity. Companies tout the high concentrations of triterpenes in their products, sometimes even more than the beta-glucans. The amount of triterpenes in commercial products varies considerably, depending on species, how the fungi are grown, and whether mycelium or fruiting bodies are used. Depending on the species, some terpenes are higher in the mycelium, and some are higher in the fruiting body. In reishi, for example, it’s more important to know what it was grown on — whether it be cooked rice, sunflower hulls, or wood chips.

Antioxidant Activity

Interestingly, the antioxidant potential in mushrooms is higher than in the most commonly eaten vegetables and fruits. Studies have shown that many phenolic compounds in mushrooms are very effective free-­radical scavengers. Free radicals are known to induce oxidative damage in physiologically important molecules; reducing free-radical damage can play a key role in mitigating a number of degenerative processes related to aging, cardiovascular disease, cancer, impaired immune function, and inflammatory diseases.

Some of these phenolic compounds are well-known antioxidants — tocopherols, flavonoids, carotenoids, some glycosides, and tannins, among others. They can be found in the fruiting bodies, mycelium, and liquid cultures of fungi. Researchers have observed antioxidant properties in the compounds found in the fungi Hymenochaete xeranticus and Tropicoporus linteus.18 An alcoholic extract of Ramaria flava, a common edible coral mushroom, exhibited a wide range of anticancer, antioxidant, and antibiotic activities.19 One study found a significant amount of total phenolic compounds in a wood-degrading fungus, Cerrena unicolor; an extract of the fungus had anticancer, antibacterial, and antioxidant effects.

Accessing the Benefits of Terpenes

Which types of terpenes you’re hoping to access determines how the mushrooms should be processed. Different types of terpenes are water soluble to varying degrees; typically, the larger and bulkier the compound, the less soluble it is in water. These are more soluble in alcohol or a mixture of alcohol and water. Monoterpenes (10-­carbon terpenes, which are often volatile and have an odor) have some solubility in water and can also be accessed via alcohol. Sesquiterpenes (15-carbon molecules) and diterpenes (20-carbon molecules) have some water solubility, especially in boiling water. Triterpenes (30-carbon molecules called sterols) tend to have low water solubility, but some can be extracted with boiling water, and even more in a pressure cooker set on high for 15 to 30 minutes. Triterpenes in the glycoside form (which means they have sugars attached to them) are an exception; they are highly water soluble.

HYDROALCOHOLIC TINCTURE. For terpenes with low water solubility, a hydro­alcoholic tincture — an 80/20 mixture of ethanol and water — works well. This is suitable for extracting triterpenes from reishi or diterpenes from lion’s mane, for instance.

DOUBLE-EXTRACTION ­TINCTURE. This combination of tincturing and hot-­water extraction accesses a variety of terpenes, as well as some beta-glucans.

DRIED TEA EXTRACT. Since hot water alone will extract a significant amount of terpenes, phenolics, and beta-glucans, I make dried tea extract. It’s less expensive to produce because it doesn’t require using alcohol, and is more appropriate for children and those avoiding alcohol.

SUMMARY OF MEDICINAL BENEFITS

The high fiber content, substantial minerals, vitamins, fatty acids, and high-quality digestible protein count among the most important medicinal components of medicinal mushrooms, as they help prevent heart disease, diabetes, and cancer — especially when included in your regular diet. In addition to their nutritional value, mushrooms have been studied for other specific medicinal benefits, including their ability to strengthen and regulate immune functions, protect us against pathogenic viruses and bacteria, and suppress cancer cells because of their strong immunomodulating effects. One of the most exciting benefits of medicinal mushrooms is the ability of fungal beta-glucans to trigger innate and adaptive immunity to focus and energize our immune power, in order to prevent and treat infections of all kinds — viral, bacterial, parasitic, and even infections caused by other species of pathogenic fungi.

Overall Immune Support

TOP CHOICES: turkey tail, reishi

All fungi contain beta-glucans, which are helpful for supporting the immune system. Turkey tail and reishi have some of the highest amounts of beta-glucans, so if immune support is one of your goals, start with these two. For powerful immune support, the recommended dose is at least 6 grams/day of a dried tea powder. If you’ll be consuming mushrooms for immune support over the long term, switching species every three months or so may prevent your body from becoming habituated to a particular type of fungal compound (and thus lessen its response). After reishi and turkey tail, other powerful immune-stimulating mushrooms include shiitake, phellinus, split gill, fu ling, and some of the other polypores (mushrooms that have pores or tubes on the underside, rather than gills) mentioned in Other Useful Polypores.

DOES THE SITE MAKE THE MEDICINE?

Wild-harvested mushrooms naturally vary in their potency; one collection may have only a quarter of the average concentration of medicinal compounds, while another may have up to four times the average amount. Where the mushrooms grow may be one reason why.

Little research has been carried out on the potential effect a substrate might have on the medicinal constituents of fungus grown on the substrate, but more studies are certainly warranted. For example, one reason chaga is so effective is that it grows primarily on birch trees, which produce betulin — a powerful chemotherapeutic agent. And according to a famous Japanese story, people with various forms of cancer would walk a hundred miles to harvest reishi mushrooms from a particular cherry orchard. These supposedly had the strongest medicinal activity of any reishi. It turns out that cherry trees contain amygdalin — a naturally occurring cyanogenic glycoside that has a reputation as an anticancer compound (and is also a major component of bitter almonds).

Cancer Support

TOP CHOICES: reishi, turkey tail, ­shiitake, chaga, split gill

For cancer support programs, start with species that have clinical trials for the strongest immune response as well as antitumor or anticancer effects: reishi, turkey tail, shiitake, chaga, and split gill. These all have high levels of beta-glucans and clinical trials showing benefits for keeping the immune response strong and for helping patients rebound after chemotherapy and radiation treatment.21 Chaga, reishi, and turkey tail should be considered at the top of the list. Turkey tail fungi have the most clinical trials that demonstrate beneficial effects using oral doses of pure (no starch residues) mycelium extracts, called PSK (polysaccharide-K). In the best of the studies, patient volunteers with several types of cancer — cancers of the stomach and colon, in particular — who took turkey tail along with chemotherapy had significantly higher five-year survival rates and fewer side effects from the chemo, such as fatigue and nausea, compared with those who only got the chemotherapy. Shiitake, reishi, chaga, and many other mushroom extracts are likely to be helpful because of their high levels of beta-glucans and their immune-­supportive effects. All of these species should be cooked and made into tea powders. Alternatively, you can purchase them as ready-made powders that have already been heat processed and finely ground.

Fungi have other classes of compounds that are known to be active against cancer cells and tumors. These include proteins, chitin, lectins, triterpenes, lipids, and phenolic compounds. Most of these work by stimulating our defenses against tumor cells, and they can act synergistically. Many fungi species, like reishi, contain a complex mixture of chemicals that activate our immune response against a variety of pathogens and cancer types.

Cancer cells are wiley. They can quickly develop ways to elude our immune response. They can develop resistance to one of the most important killing mechanisms we have: the coating of tumor cells (called opsonization) with iC3b, which is a protein fragment that marks cancer cells for destruction. Fungal beta-glucans are able to override this resistance by activating natural killer cells.

Other exciting research has to do with the synergistic effects of fungal beta-glucans with the use of monoclonal antibodies for treating some cancers that have been very difficult to treat, such as melanoma of the skin that has spread to internal organs and the brain.

Preventing and Treating Infections
TOP CHOICES: shiitake, phellinus, agarikon, fu ling, chaga, reishi, red-belted polypore, birch polypore, agaricus

For prevention and treatment of infections, the immune response of the individual being attacked by microbial pathogens is the key, so fungi with the highest beta-­glucan content are the most helpful; research shows that the chitin, mannans, phenolics, and terpenes also contribute to the overall immune-strengthening and regulating effects. Some mushrooms — such as turkey tail, oyster mushroom, agarikon, fu ling, chaga, reishi, red-belted polypore, birch polypore, and the russulas (used externally) — have direct antiviral and antibacterial effects as well. Of real interest are the many studies that show that “pretreatment” with fungal beta-glucans — taking them ahead of a potential infection, to prime the immune system — can protect against bacterial, parasitic, and viral infections, such as those caused by coronaviruses and seasonal influenza.

Heart Disease Prevention and Support
TOP CHOICES: reishi, shiitake, oyster

All edible fleshy mushrooms — such as shiitake, maitake, and agaricus — can be cooked and eaten to provide fiber and antioxidant phenolic compounds, helping to slow the progression of heart disease and help heal from it as well. Shiitake and oyster mushrooms both have well-known cholesterol-­regulating effects. Reishi also offers a special cardiovascular-protective activity because of its triterpenes, plus cholesterol-­lowering effects, liver support, and strong anti-inflammatory effects, as well as improving circulation. It is used in traditional Chinese medicine for benefiting the cardiovascular system. According to the doctrine of signatures (the belief that the shape of a plant or plant part indicates the body part it can be used to treat), the color red is associated with the cardiovascular system as well. If you have a family history of cardiovascular disease, high cholesterol, or even diagnosed ­atherosclerosis, I recommend taking a teaspoon of extract powder once or twice daily in water.

Excerpted from Christopher Hobbs’ — Medicinal Mushrooms the Essential guide.