A mushroom is the reproductive structure of a fungus, belonging to a biological kingdom distinct from plants or animals. The fruiting body, which we recognize as a mushroom, contains a dense supply of bioactive compounds. The term “functional mushroom” refers to a specific category of these fungi prized for properties that extend beyond basic nutritional value. Used for centuries in traditional systems, these mushrooms support various aspects of health and well-being. This article explores how these fungi are classified, the core compounds that enable their effects, popular varieties, and how they are prepared for consumption.
Classification and Definition of “Functional”
A mushroom achieves “functional” status when its compounds demonstrate a specific, measurable physiological benefit to the body. This classification separates them from culinary varieties, such as white button or cremini mushrooms, which are consumed primarily for flavor and basic nutrients. Functional mushrooms contain concentrated molecules that offer targeted support for the immune system, cognitive function, or stress response.
This group is distinct from psychedelic mushrooms, as functional varieties do not contain psychoactive compounds like psilocybin. Their functionality is rooted in traditional use, often as adaptogens, which are natural substances believed to help the body resist the damaging effects of various stressors.
The Core Components: Beta-Glucans and Triterpenes
The beneficial properties of functional mushrooms are primarily attributed to two major classes of compounds: polysaccharides and triterpenes. Beta-glucans are the most widely studied polysaccharides; they are complex, long-chain carbohydrates found within the fungal cell walls.
The structure of mushroom beta-glucans allows them to interact with immune cell receptors, such as Dectin-1 and Toll-like receptors, on immune cells like macrophages. This interaction modulates and stimulates the body’s immune response, essentially priming the immune system rather than directly attacking pathogens. Because they are not easily digested, these compounds travel through the gastrointestinal tract, where they engage with immune tissue.
Triterpenes, the other major component, are steroid-like compounds known for their bitter taste, particularly noticeable in species like Reishi. These compounds are responsible for the adaptogenic and hepatoprotective (liver-protecting) effects associated with certain functional mushrooms. Triterpenes exert anti-inflammatory effects by helping to suppress the activation of the NF-κB signaling pathway. Specific triterpenes, such as ganoderic acids found in Reishi, possess potent antioxidant activity, helping to protect liver cells from oxidative stress.
Profiles of Leading Functional Varieties
Each functional mushroom variety is recognized for its unique profile of bioactive compounds that support specific areas of health.
Lion’s Mane
Lion’s Mane (Hericium erinaceus) is widely studied for its potential to support cognitive function and nerve health. This mushroom contains unique molecules, hericenones and erinacines, which are thought to stimulate the production of Nerve Growth Factor (NGF) in the brain. Supporting NGF may aid in the maintenance and repair of neurons, potentially supporting memory and focus.
Reishi and Cordyceps
Reishi (Ganoderma lucidum) is revered for its adaptogenic qualities, traditionally used to promote relaxation and help the body manage stress. The high concentration of triterpenes contributes to its calming effect, supporting restful sleep and overall vitality. Cordyceps (Cordyceps sinensis or Cordyceps militaris) is often associated with energy and endurance, particularly in athletic performance. This fungus is believed to help the body utilize oxygen more efficiently and may support the production of adenosine triphosphate (ATP), the primary energy molecule in cells.
Turkey Tail and Chaga
Turkey Tail (Trametes versicolor) is a potent source of immune-modulating beta-glucans, including polysaccharide-K (PSK) and polysaccharide-peptide (PSP). These compounds have been the subject of extensive research, particularly in Asia, for their ability to support the immune system. Chaga (Inonotus obliquus) is known for its high concentration of antioxidants and is often used to support immune and digestive health.
Methods of Preparation and Consumption
The complex structure of functional mushroom compounds requires specific preparation methods to make them bioavailable for the human body. The cell walls of fungi are made of chitin, a tough, indigestible material that encapsulates the beneficial beta-glucans and triterpenes. Simple cooking or eating the raw mushroom often fails to break down this chitin barrier adequately.
Proper preparation involves extraction, typically using hot water or alcohol. Hot water is necessary to dissolve the water-soluble beta-glucans, which are heat-stable polysaccharides. Alcohol, or a tincture, is used to extract the alcohol-soluble triterpenes and other non-polar compounds. The most comprehensive products use a dual extraction method, combining both water and alcohol to ensure a full spectrum of active compounds is delivered.
Functional mushrooms are most commonly consumed as concentrated powders, capsules, or liquid extracts added to coffee, tea, or smoothies. They are sold as dietary supplements, meaning they are regulated as food products and not drugs by the Food and Drug Administration. Consumers should look for products that specify the type of extraction used and confirm that the final product utilizes the mushroom’s fruiting body rather than mycelium grown on grain.