They have names like lion’s mane, turkey tail, chaga, reishi, and oyster mushroom. And they have become increasingly popular as supplements and powders that claim to cure all kinds of ailments.
They are called medicinal, or functional mushrooms. They are mushroom extracts that have been used for thousands of years in traditional Chinese medicine and now frequently appear in the West as a fashion trend for health and well-being Rapé.
They are touted as potential cures for many things, from relieving anxiety and depression, improving immunity and cognitive functions, to lowering cholesterol and hypertension and aiding in cancer recovery.
The truth is that functional mushrooms are a multi-billion dollar industry. According to the market research company Allied, in 2020 the global market for the product was valued at almost US$8 billion and it is projected that by 2030 its value will reach US$19.3 billion.
Up to 17 different medicinal mushroom supplement or powder products can be found in health food stores in many Western countries , and experts say this boom is not expected to end anytime soon.
But how true are the claims of the healing properties of medicinal mushrooms? Are these really claims backed by science?
“These mushrooms are the hot commodity at the moment,” Dr Emily Leeming, a nutrition researcher at King’s College London and registered nutritionist.
“They are promoted as drugs to have a super brain, to potentially help you end anxiety, improve your depression, among other benefits for the mind that are claimed on the labels of these products.”
“I think that these claims, at this time, are quite exaggerated, we do not have any evidence of these benefits in humans or the evidence that there is is very limited,” says the expert.
Studies on fungi and their effects have been carried out for many years, but most of the research has been carried out in cell cultures or mice and the results, experts say, do not always translate to humans.
“In China, many studies have been carried out that support the effects that these mushrooms have, but their effects have been studied in cells growing in cultures, or in experiments with mice that have been fed enormous amounts of mushrooms,” he tells the BBC Professor Nicholas Money, an expert in mycological biology at Miami University in Ohio.
“But there is a huge philosophical and scientific gap between those types of experiments and taking them to the levels of Western medicine to see if they really work.”
“There is currently no evidence that these products have any proven effect on human health and well- being ,” says Professor Money.
Professor Money published a review of studies on the effects of medicinal mushrooms in 2016. The goal of his review was to answer the question: are these mushrooms medicinal?
“My conclusion was no, based on the type of evidence we typically look for when we study prescribed medications.”
“With medicines what we expect is that they work and that same logic does not apply to medicinal mushrooms.”
The problem, says the expert, is that in most countries medicinal mushrooms are sold as food and are not subject to the same type of regulations that prescription medications are subject to.
“Therefore we totally depend on what the companies that market these products say ,” says the expert.
The “fashion mushrooms”
According to recent estimates, there are about 2,300 species of edible and medicinal mushrooms known in the world.
But as Professor Money explains, the fungi that are being presented as fashionable “therapeutic stars” are less than a dozen. Among them:
Reishi (Ganoderma lucidum), which is a polypyrous mushroom that has a striking red polished surface Shitake (Lentinula edodes), a brown mushroom with an intense aroma
Turkey tail (Coriolus versicolor) that is shaped like a fan of multicolored stripes
Cordyceps (Ophiocordyceps unilateralis) a famous parasitic fungus that enters dead insects and replaces the host
Chaga (Inonotus obliquus), another parasitic fungus that appears on dead birch trees in an irregular shape and has the appearance of burnt charcoal
Lion’s mane (Hericium erinaceus), which grows in rounded clumps with long white beard-like filaments
“Beautiful organisms”
“Mushrooms have always been seen as products that have supernatural powers and are really beautiful organisms,” says Nicholas Money.
“But I am really surprised by this popularity that mushrooms have today.”
There is no doubt that the mushroom kingdom is fascinating. They are architects of the natural world and sustain critical ecosystems.
In their underground networks they can absorb and recycle nutrients from the plants around them and have helped produce many basic products of life, including drugs such as the antibiotics penicillin and cephalosporins, and the cholesterol-lowering lovastatin.
As a food, mushrooms have enormous nutritional properties, they are an important source of plant protein, vitamins D and B, they have several essential amino acids, and they are rich in fiber and minerals.
Should we then eat more mushrooms for their nutritional properties?
“I know not everyone likes mushrooms but they are actually very good as nutritious foods, they are a fabulous source of fibre, and they have a huge amount of beta-glucans, which are a type of complex carbohydrate,” explains Dr Emily Leeming from King’s College of London.
Beta-glucans, found in grains such as oats, have been said to help reduce bad cholesterol levels in the blood. It has also been said that these compounds have benefits on the immune system because they act favorably on the intestinal microbiome, which is linked to the immune system.
But it is still not known what impact the beta-glucans contained in mushrooms have on our intestinal health.
“We know that mushrooms contain those beta-glucans that are very beneficial for the intestinal microbiome. But we need much more research to understand how fungi work as specific foods and their impact on our gut bacteria,” says Dr Leeming.
“They likely have many benefits. But it’s more important to eat a variety of different, healthy foods rather than focusing on specific products like mushrooms, which are the hot heroes for gut health right now.”
Is the future fungal?
Despite the multi-billion dollar market for mushroom supplements, Western pharmaceutical science has not really begun to explore the potential of mushrooms as medicines.
With advances in genomics and techniques to extract genetic information from organisms, there is growing hope that a greater variety of compounds produced by fungi can be isolated, purified and used in specific doses to treat human diseases.
“There are probably many, many compounds within fungi that have very powerful effects on our physiology,” says Professor Nicholas Money.
“But because we haven’t done any serious science to study the pharmacological properties of mushrooms and their compounds we’re not really exploring this full range of possibilities and I hope this comes to fruition.”