Mushrooms are some of the most exciting types of food and have been used as both food and medicine for a very long time. In particular in Asia, mushrooms have a very rich history of medicinal usage. Numerous mushroom species have attested medicinal qualities and over 270 of them are recognized by scientists. Even the oldest versions of the Chinese Materia Medica prove that mushrooms were used in the local herbal medicine.
Mushrooms continue to grow in the wild and most species are still harvested from nature. However, we can cultivate many types today and important breakthroughs have been made in this field in the last decades. Asian countries such as China, Korea or Japan have focused on the study of mushrooms and have dedicated big resources to their research. These studies have validated the traditional medicinal uses, as well as discovered new ones.
Studies conducted both in laboratories and during clinical trials have revealed one of the most valuable effects of mushrooms: they can limit the expansion of tumours and boost the immune function due to some of the compounds in their composition. The most exciting of these are the complex molecules with a branched chain structure known as polysaccharides. These have been thoroughly investigated starting in the 50’s and consist of linked smaller sugar molecules. Scientists have discovered their very strong effects on immunity and against cancer cells.
A study conducted in Germany has proven an interesting fact: the polysaccharides with immune-stimulating effects found in mushrooms are also present in more complex plants. These include astragalus, which plays a key role in Chinese herbal medicine, as well as the widespread Echinacea. These huge molecules have the ability to trigger a reaction from the human immune system, with no actual side effects. This is because polysaccharides are very similar to the molecules that form the cellular walls of bacteria, so the immune system is tricked. In response, the body activates killer T-cells and macrophages, as well as other immune reactions. Scientists now believe that heteropolysaccharides are the most important compounds in mushrooms and many ongoing research programs focus on their properties.
The polysaccharides found in fungi are often bound to proteins at molecular level. If proteins enter the body, they usually trigger an immune response since they are used to identify various organisms and are unique to them. Proteins start immune responses that aren’t always beneficial. Instead of stimulating the immune system to respond to threats, they can trigger an over-reaction of the immune function that becomes a harmful allergic reaction. Some of the proteins associated with allergies are the ones found in pollen, casein in dairy products or the gluten in wheat and other cereals. Proteins in the stings of bees and other insects can even start deadly allergies.
Proteins in medicinal mushrooms don’t trigger such extreme reactions, or at least none have been reported so far. However, some people are very sensitive to mushrooms and can have strong reactions even to edible varieties like Boletus edulis, which are safely consumed usually. Scientists have failed so far to identify the exact allergens in such rare cases. Most mushrooms have the opposite effect and actually improve the effectiveness of the immune response.
The precise role of polysaccharides or protein-bound polysaccharides is not fully understood and the scientific community still tries to find answers to a number of questions. It is not clear if these compounds are the ones responsible for the medical benefits of the plants and mushrooms that include them.
Rats, mice and other test animals are extensively used in modern scientific studies. Instead of oral administration, these test animals are usually injected with extracts of the active components of medical mushrooms, in order to research their effectiveness. Since fungi are part of the human diet, one might wonder why these tests are even relevant for our health, since we ingest them.
There are many aspects that require further research. Scientists are trying to establish if the large molecules named polysaccharides are even able to be used by the body, since they must pass through the very strong acids inside the stomach, as well as the duodenum and its highly alkaline environment. It is not fully understood if these heavy molecules must be injected in order to work, or if they can just be eaten. Tinctures are mushroom extracts mixed with water and alcohol, researchers are trying to find out the effect of alcohol on them and the associated proteins. It is unclear if they are destroyed or their effect is diminished in such a case. In addition, the exact role of polysaccharides is unknown, as well as their influence on macrophage activity, T-cell production and growth, or other parts of the immune system. Another question is the duration of the positive effects.
The ingestion of polysaccharides appears to boost immunity, even if all the above questions remain unanswered for now. Clinical evidence also proves that their effectiveness is not decreased when combined with low concentrations of alcohol, of no more than 25%. Echinacea purpurea is still used today to produce a very popular and old remedy that combines freshly pressed juice from the plant with about 24% alcohol in ethanol form. This is a very effective cure that doesn’t include any alkyl amides or other potentially bioactive components, so the producer lists polysaccharides as the active ingredient that stimulates immunity.
Researchers now know that the effectiveness of polysaccharides depends on their molecular weight. The very large compounds can trigger a variety of immune responses, while heating reduces their size and makes the molecules a lot weaker than normal. Tests made on compounds with a molecular weight of about 6400 (compared to the molecular weight of 800,000) found they only stimulate glucose use and the production of the anti-bacterial lysosomal enzyme, with no other benefits.
The powerful immune-boosting and anti-tumour effects of numerous varieties of polysaccharides and protein-bound polysaccharides, which are connected naturally to proteins, are well-known by scientists.
Health benefits of medicinal mushrooms
Mushrooms are famous for their ability to improve immune reaction and fight cancer. However, they have many other medical benefits, some of which haven’t been properly researched. These include decreasing the level of cholesterol, anti-viral and anti-microbial effects, as well as antioxidant, anti-hypertensive, anti-inflammatory, anti-diabetic and liver protecting properties. All of the top pharmaceutical giants in the world are investing heavily in mushroom research, since they include many bioactive molecules with huge potential that haven’t been investigated yet.
Consuming mushrooms can prevent many diseases, both mild and severe. This is due to their adaptogen, antioxidant, immune stimulant and immune modulator properties. The fruiting bodies and mycelium of more than 30 mushroom species are currently used for medical purposes. The split-gill, turkey tail, shiitake, reishi, maitake, cordyceps and blazei mushrooms are the most used and have been researched intensively. However, there are many other varieties that are used in medicine and have shown excellent qualities. Some of the species that have proven their effectiveness in clinical tests are tinder polypore, enoki, mesima, chaga or oyster mushrooms. All medicinal mushrooms are a great source for the so-called essential sugars and contain big amounts of bioactive compounds.
Since mushrooms stimulate the immune system, they are extremely useful in the fight against cancer and various infections. A stronger immune response releases more white blood cells, as well as antibodies, complement proteins and cytokines. Very big polysaccharides scientifically known as 1,3 ß-D-glucans are bound to the chitin structure of the mushroom cell walls. Smaller branching chains named 1,6 ß-D-glucans are also present in their composition. It is also possible to encounter fungi with 1,6 ß-D-glucans with 1,3 ß-D-glucan branching. Since the exact layout and structure is different from one mushroom species to another, the immune responses triggered are also distinct.
Macrophage cells show tiny parts of mushroom ß-glucan on their surface as antigens, which are presented and read by the T-cells that act as helpers. The T-cells will then produce cytokines, which are compounds that stimulate the immune system and trigger a wave of responses. The macrophages also release these chemicals, which in turn stimulate the body to produce more B and T cells, as well as the proteins required for an effective immune reaction. Reishi, maitake and multi-mushroom blends are some of the special fungi that are able to make killer cells significantly more effective and limit the size of tumours through the apoptosis of cancer cells.
Antiseptic compounds are also found in larger amounts in both macrophages and neutrophils. There are many such compounds, for example hydroxyl radical, hydrochloruous acid, nitric oxide, super oxide radical, hydrogen peroxide as well as other toxins and natural enzymes. In order to keep these compounds away from the cytoplasm of the white blood cell, they are produced inside lysosomes, which are sacs sealed by membranes. Another sac with a membrane, named phagosome, is employed to envelop any pathogens that are captured by a macrophage or neutrophil, to protect their own cytoplasm. The lysosome and phagosome will then merge, killing the bacteria or virus with the toxins inside them. Mushroom ß-glucan fragments are very important to boost the effectiveness of the human immune system by activating its defences and making it react faster to any threats.
Mushroom mycelium grown on brown rice provides arabinoxylanes, a strong antigen that triggers a powerful immune response by stimulating the entire system. The mycelium releases enzymes into the rice bran, which decompose it into smaller fragments. The polysaccharides known as arabinoxylane consist of a xylose main chain and multiple additional side chains of arabinose. These compounds vastly improve the activity of natural killer cells, as well as the levels of cytokine, which cause tumour necrosis and prevent the expansion of cancer. They also increase the number of white blood cells, especially the production of B and T cells. In vitro tests have revealed that arabinoxylanes can kill viruses and even control the deadly HIV virus. Many types of mushrooms cultivated on brown rice will produce arabinoxylanes in their mycelium. A powder with a concentration of arabinoxylane of at least 8% can easily be produced by drying the biomass of medicinal mushroom mycelium and brown rice.
Mushrooms are famous for their immune stimulating effects but actually provide many other key nutrients. They are a major source of glyconutrients, which are a type of essential sugars. Many people with low immunity actually suffer from a lack of these compounds, so consuming mushrooms can boost their natural defences. The reason is that glyconutrients are actually part of the internal communication network of the immune system and are used as both a method of identification and to share information about pathogens. The glycoproteins, glycolipids and proteins help communication and reporting and are located in the membranes of cells.
The glycoprotein membranes most often include the following sugars: N-acetylneuraminate, N-acetylgalactosamine, xylose, mannose, N-acetylglucosamine, fucose, glucose and galactose. Cordyceps and some other medicinal mushrooms provide large amounts of xylose, galactose and N-acetylglucosamine, as well as mannose that further transforms into the essential sugars fucose and N-acetylneuraminate. People who don’t have enough of these essential sugars will have a weak immune system because their cells are unable to communicate properly with each other due to the low amount of glycoproteins.
Human antibodies are mostly built from proteins and sugars, with a content of carbohydrates that varies between 3% -10% of their total mass. They are some of the most effective weapons used by the immune system in the fight against infection. They play a dual role: they mark pathogens to be attached by phagocytes, a process known as opsonization, but also destroy both toxins and germs directly. Their impact is huge, studies have revealed that tagging makes phagocytes between 10 and 1000 times more effective in identifying and engaging bacteria and viruses, especially if complementary proteins are also involved.
Pathogens can develop resistance to drugs and antibiotics, but never to antibodies. This is because the body employs several types of B cells, which target a specific microbe with different antibodies, making it very difficult for them to survive. Scientists estimate there are over 100 billion different antibody types in the arsenal of the human body. People with a lack of glyconutrients are unable to synthetize the same amount of antibodies as a normal person. This is what makes mushrooms so valuable for immunity: they supply the ingredients that make it stronger but also stimulate it directly.
Common medicinal mushrooms
- Artist’s Conk
- Birch Polypore
- Black Hoof
- Black Morel
- Black Truffle
- Burgundy Truffle
- Gilled Polypore
- Lion’s Mane
- Morel Mushroom
- Red-Belted Polypore
- Russula Mushroom
- Shaggy Mane
- Snow Fungus
- Tinder Conk
- West Coast Reishi
- White Truffle
- Wood Ear
- Zhu Ling