Mushrooms Gain Ground in Medicine Despite Limited Evidence

Mushrooms have attracted growing interest in nutrition and medicine because their bioactive compounds have anticancer, metabolic, anti-inflammatory, antiviral, neuroprotective, and immunomodulatory effects. However, stronger clinical evidence is required.More than 1.5 million mushroom species have been identified to date. Of these, approximately 14,000 produce a carpophore, the aboveground reproductive structure of higher fungi commonly known as the fruiting body, whereas nearly 200 are edible. In addition to their nutritional value, mushrooms are an important source of bioactive compounds.Mushrooms are rich in water, protein, fiber, vitamins, and minerals, and also contain compounds with antioxidant, anti-inflammatory, antiviral, antidiabetic, hepatoprotective, neuroprotective, and immunomodulatory properties. Nearly 130 therapeutic properties of medicinal mushrooms have been reported. These characteristics have increased interest in their potential applications in nutrition and medicine and have attracted growing attention from biomedical researchers.Bioactive CompoundsEdible mushrooms, including Agaricus bisporus, Pleurotus ostreatus, Lentinula edodes, and Ganoderma lucidum, contain several families of compounds that may contribute to their pharmacologic effects:Polysaccharides: Beta-glucans may help improve postprandial blood glucose levels and have immunomodulatory properties.Phenolic compounds: Phenolic acids, flavonoids, and alkaloids are associated with antioxidant and anti-inflammatory activities. Psilocybin, an alkaloid, has also been studied in psychiatry.Triterpenoids: These compounds may contribute to neuroprotective and anticancer effects.Ergosterol: This compound is a precursor of vitamin D2 after ultraviolet exposure and has antioxidant and anti-inflammatory properties.Pharmacologic EffectsAnticancer ActivityA study analyzed eight medicinal mushrooms across several tumor models, including breast, colorectal, gastric, lung, liver, and prostate cancers. In vitro and in vivo studies found their bioactive compounds inhibited cancer cell proliferation, migration, invasion, and angiogenesis. These effects are associated with several mechanisms, including activation of immune functions, apoptosis, and autophagy.Another study identified the potential role of some bioactive compounds as adjuvants that could enhance the effectiveness of chemotherapy and limit chemoresistance. Mushroom extracts inhibited tumor proliferation and enhanced the effects of chemotherapy.Several clinical studies have assessed the potential adjuvant effects of mushrooms. A large observational study suggested improved overall survival among patients who received polysaccharides isolated from Coriolus versicolor in addition to adjuvant chemotherapy after gastrectomy for gastric cancer.Another randomized study involving 141 patients with advanced laryngeal or pharyngeal cancer found that adding D fraction, a polysaccharide-rich extract derived from Grifola frondosa (maitake), to chemoradiotherapy improved functional recovery at 6 months and overall survival. The treatment also reduced several severe toxicities, including neutropenia, anemia, and mucositis, and limited the early decline in quality of life.A literature review of preclinical and clinical data suggests that several mushrooms may help alleviate pain, fatigue, cognitive and digestive symptoms, and certain physical limitations associated with cancer treatment. Taken together, these findings suggest the potential applications of mushrooms in supportive cancer care.Carbohydrate MetabolismMedicinal mushrooms may influence insulin resistance by modulating the microbiota, reducing glucose absorption, improving blood glucose levels and cellular glucose uptake, and regulating insulin secretion.Polysaccharides, particularly beta-glucans and triterpenoids, may play a central role through their effects on the microbiota, inflammation, and metabolic pathways associated with insulin resistance.Other ActivitiesMushrooms have also been studied for several other potential health benefits:Cardiovascular: Bioactive peptides and triterpenes in mushrooms may have antihypertensive effects by inhibiting angiotensin-converting enzyme.Immunomodulatory: Mushroom beta-glucans and phenolic compounds may activate or modulate T and B cells and support immune function.Antiviral: Mushroom triterpenoids and polyphenols may have antiviral activity against herpes simplex virus, influenza, and HIV.Neuroprotective: Compounds in Hericium erinaceus may have neuroprotective effects by stimulating nerve growth factors. Various mushroom compounds are also being investigated for their potential role in Alzheimer’s disease.Antiobesity: Bioactive compounds in mushrooms such as L edodes and P eryngii may reduce lipid storage and help regulate blood lipid levels.Current ApplicationsSome mushrooms have been used in nutritional approaches to health. Bioactive compounds from G lucidum (reishi), L edodes (shiitake), G frondosa (maitake), Cordyceps, and H erinaceus are used in the form of nutraceuticals and dietary supplements, including standardized extracts and powders, for purposes such as immune support, metabolic regulation, and antioxidant protection. However, scientific evidence supporting these health claims remains limited.Future ProspectsThe available data support further research into the potential therapeutic applications of mushrooms in pharmaceutical and medical research. However, large-scale, standardized clinical trials are needed because most studies have been conducted in vitro, often using simple protocols, while relatively few in vivo studies are available. Further research is needed to develop more effective methods for extracting and identifying active compounds and to better understand their mechanisms of action.This story was translated from Univadis France, part of the Medscape Professional Network.