Medicinal mushrooms have been traditionally used for protection against infectious diseases and various cancers. (3) These mushrooms have a long history of use for supporting health, particularly in early Chinese, Egyptian, Greek, Mexican, and Roman cultures. (4) In fact, in 1991 a 5,300 year-old mummy was discovered carrying birch polypore fungus, which exerts a purgative effect and may have been used to treat the mummified person’s intestinal parasites. (1)
Modern research has shown that medical mushrooms provide a rich source of nutrients and bioactive compounds that are associated with several health effects, including supporting the immune system. (20) Read on to learn more about medicinal mushrooms, their health benefits, the top mushrooms for immune support, and how to consume medicinal mushrooms.
What are medicinal mushrooms?
Medicinal mushrooms are edible macroscopic fungi (visible to the naked eye) that are used for their beneficial health properties. (15) Fungi, which include yeasts, molds, and mushrooms, live on the dead matter found in soil or on plants, animals, and other fungi. (4) There are an estimated 14,000 to 22,000 known species of mushrooms worldwide, (14) of which approximately 20 to 30 are cultivated edible species and approximately 15 species are wild-foraged for consumption. (4) These mushrooms may be consumed as functional foods or as dietary supplements. (15)
Mushrooms are a source of many nutrients, including fiber, protein, selenium, and potassium, as well as the vitamins B1, B2, B12, C, D, and E. (20) Additionally, they possess several bioactive components, such as alkaloids, flavonoids, (20) terpenes, phenolic compounds, polyunsaturated fatty acids, and polysaccharides. (16) Notably, β-glucan, a polysaccharide commonly present in mushrooms, has been studied for its immune-stimulating and prebiotic properties. (10)
Health benefits of mushrooms
Research examining the health effects of mushrooms has identified approximately 130 possible therapeutic properties, including:
- Immunomodulating (21)
To date, much of the research on medicinal mushrooms is based on animal or in-vitro trials. However, some early clinical trials suggest that mushroom intake may reduce the risk of breast cancer, (4) and may improve cancer-related symptoms, such as insomnia and sweating. (14)
Several mechanisms have been proposed to explain the beneficial effects of mushrooms for immune health. Certain mushrooms may positively influence the gut microbiota, improving protection against pathogens. (10) Further, several mushrooms have been shown to support immune health by enhancing the innate and adaptive immune responses. (21) Conversely, certain mushroom extracts may also suppress the immune response, thereby exerting anti-allergic effects. (14)
The top 8 mushrooms for immune support
Outlined below are eight of the top mushrooms with immune-supportive properties.
1. Chaga (Inonotus obliquus)
Chaga mushroom, also referred to as birch mushroom and chaga conk, is a dark brown and black fungus that grows most often on birch trees. Several compounds found in chaga may result in its beneficial effects, including anti-oxidant polyphenols, as well as betulin and betulinic acid, which are associated with anti-cancer effects. (6)
2. Cordyceps (Ophiocordyceps sinensis)
Though not technically a mushroom, cordyceps is a rare caterpillar fungus that grows only in high-altitude regions of Sikkim, a state in northeast India. (14)(18) The bioactive components in cordyceps include polysaccharides, cordycepin, and cordycepic acid. An eight-week study in healthy Korean individuals found that supplementation with cordyceps extract was associated with increased activity of natural killer immune cells (NK-cells). This change was accompanied by improved immune regulation compared to controls. (12)
3. Lion’s Mane (Hericium erinaceus)
Hericium erinaceus is commonly known as lion’s mane mushroom due to its white, fur-like appearance. Animal models have demonstrated that lion’s mane may promote beneficial gut microbiota growth and be associated with reduced colon tissue damage in cases of inflammatory bowel disease (IBD). The researchers suggest that lion’s mane may help regulate the immune system and improve the health of individuals with IBD, however, clinical trials are needed to confirm this in humans. (2)
4. Maitake (Grifola frondosa)
Maitake is a culinary and medicinal mushroom that has shown anti-cancer activity on breast cancer, melanoma, and hepatoma cells in animal studies. Proteoglucan, a component of maitake, has been associated with the immune-stimulating effects of the mushroom. In mouse models, proteoglucan has been shown to decrease mammary tumor cell behavior. (10) Further, in in-vitro and animal studies, polysaccharides found in maitake have been shown to exert anti-viral activity against hepatitis B and human immunodeficiency virus (HIV). (8)
5. Oyster (Pleurotus)
Oyster mushrooms are a genus of fungi that include several species, such as Pleurotus ostreatus and Pleurotus florida. (5) In vitro research has found that the polysaccharides present in P. ostreatus mushrooms may activate NK cells against lung and breast cancer cells. (3) Additionally, an extract of P. florida, which contains a number of active components, including phenolics, flavonoids, and polysaccharides, was shown to have anti-inflammatory and analgesic effects in animal models. (5)
Culinary mushrooms such as oyster, shiitake, and maitake have beneficial properties.
6. Reishi (Ganoderma lingzhi)
Reishi is commonly referred to as the “king of mushrooms” (5) or the “mushroom of immortality”. (20) It has been shown to prevent or treat various diseases (20) and modulate the inflammation associated with a high-cholesterol diet. (5) The health effects of this mushroom may be a result of its ability to regulate microbiota composition, as the polysaccharides found in reishi demonstrate prebiotic effects and may increase counts of beneficial bacteria in the host. (5)
7. Shiitake (Lentinula edodes)
Shiitake mushrooms have been traditionally used to treat conditions such as the common cold. A four-week clinical trial suggests that shiitake intake was associated with favorable changes in secretion patterns of various immune compounds. These changes may indicate an improvement in gut immunity and an anti-inflammatory response. (4) As with many other mushroom varieties, shiitake may have anticancer effects. Lentinan, which is a glucan derived from shiitake, is currently used as a complementary treatment for tumors, particularly in China and Japan. (14)
8. Turkey Tail (Coriolus versicolor)
The turkey tail mushroom obtains its name from the tan and brown rings on its surface, similar in appearance to the tail feathers of a turkey. (19) In traditional medicine, turkey tail has been used therapeutically for fungal infections, cancer, and acquired immunodeficiency syndrome (AIDS). (10) Contemporary research in animal models of breast cancer suggests that C. versicolor exerts an anti-tumor and anti-metastasis effect, indicating that it may reduce the risk of developing secondary cancerous growths. Polysaccharide-K (PSK), a proprietary formulation of turkey tail, is approved in Japan as a complementary cancer treatment. (19) A 2007 meta-analysis of over 8,000 patients conducted by the Kyoto University Graduate School of Medicine in Japan found that PSK in combination with chemotherapy increased the survival rate of patients following gastric cancer resection. (17)