Can mushrooms with healing properties truly enhance human well-being?
Sheila Dillon, a well-known journalist, revealed some personal details during an episode of BBC Radio 4’s The Food Programme. She was diagnosed with bone marrow cancer in 2011 and started taking mushroom supplements after learning about how they helped patients in Japan undergoing radiotherapy and chemotherapy. She shared that there is significant evidence supporting the effectiveness of these supplements. Her oncologist even mentioned that she is at risk of becoming a “super-responder” during her last visit.
Dillon expressed uncertainty regarding any possible connection between the supplements and her successful treatment. However, she is not alone in considering the potential of fungi to be a more effective treatment for various health conditions than what is generally recognized in Western medicine. According to a market research company, the global market for functional mushrooms is projected to increase from $8 billion in 2020 to $19.3 billion in 2030. Popular retailer Holland & Barrett currently carries 17 different types of mushroom supplements. “In recent months, there has been a 70% rise in purchases of mushroom products,” says Rachel Chatterton, head of food at the company. “And we anticipate that this ‘shroom boom’ will continue to thrive.”
Many products containing medicinal mushrooms are advertised with promises of various health benefits. For instance, the Bristol Fungarium markets extracts from fungi that purportedly reduce anxiety, prevent wrinkles, regulate blood pressure, and alleviate hot flashes. The range of ailments that these mushrooms are said to treat includes heart disease, type 2 diabetes, allergies, and cancer. However, it is unclear if these claims are backed by scientific research or if they are simply a passing trend.
In a former grain barn on a hill at the end of a country lane in north Somerset, groups of bulbous, cream-coloured young reishi heads rear up on dark red stalks, alongside rows of giant cauliflower-like lion’s mane poking out from metal shelving units. This is the Bristol Fungarium’s growing room. Next door, seven employees are hard at work turning fungi into tinctures and packaging them to fulfil orders.
The company is expanding by building a new growing room to increase production. According to founder Tom Baxter, sales reached approximately £1.4m in the past year and are projected to double in the next 12 months.
Approximately 50% of the Bristol Fungarium’s profits are generated from sales of lion’s mane. According to promotional materials from the company, this particular mushroom may have positive effects on individuals with mild dementia, as well as potential benefits for those with inflammatory bowel disease (IBD) and attention deficit hyperactivity disorder (ADHD). However, there is limited evidence from human trials to support these claims. Studies have shown that extracts of lion’s mane can stimulate the growth of nerve cells in laboratory dishes and in rodents.
According to Professor Nicholas Money, a mycologist at Miami University in Ohio, the human body contains trillions of cells that interact with each other and with microbes in our microbiome. In a review on medicinal mushrooms published in 2016, he states that while preliminary studies on cells and animals are intriguing, it is ridiculous to assume that the effects observed in cultured human cells can be applied to treating serious conditions.
Baxter recognizes that several assertions about the medicinal properties of mushrooms are derived from studies on cell cultures. However, he does emphasize two clinical trials conducted on lion’s mane mushrooms, one of which was published in 2009. The results showed that extracts of the mushroom enhanced cognitive test scores in older adults with mild cognitive impairment, while the other trial suggested potential benefits for individuals with mild Alzheimer’s disease. It is worth noting that the first trial involved only 15 participants, and the second study included only 20. Additionally, both trials were conducted by researchers affiliated with companies that produce and sell mushroom supplements.
Reishi, a substance with a long history dating back over 2,000 years, has been claimed to have numerous health benefits. These include boosting the immune system and improving gut health, as well as reducing fatigue and enhancing sleep. Research has also shown that reishi may have anti-cancer properties, as demonstrated in cell culture and animal studies. According to Giuseppe Venturella, a botanist and mycologist from the University of Palermo in Italy, reishi has the ability to activate the body’s natural killer cells, which can target cancer cells and increase cell death in these harmful cells.
Although the majority of studies on the fungus have been conducted in laboratory settings, a review has identified 26 human trials of reishi. These trials have shown potential benefits for individuals with conditions such as high blood pressure, type 2 diabetes, heart disease, hepatitis B, and cancer. However, the author of the review noted that these findings may be influenced by factors such as participants being aware of receiving the treatment, limited sample sizes, and a lack of additional research to confirm the results.
Turkey tail extracts have been utilized as conventional treatments for cancer in Japan since the 1970s and in China since the 1980s. According to Baxter, a well-known expert, turkey tail serves as an immune system regulator and has been shown to effectively treat lung cancer and various other types of cancer.
Dr. Karen Pilkington and her team at the University of Portsmouth conducted a review of seven randomized controlled trials that looked at the effects of PSK (polysaccharide-K), an extract from turkey tail, on reducing side effects of radiotherapy or chemotherapy in patients with colorectal cancer. Due to limitations such as small sample sizes and the absence of placebo control groups, the results were inconclusive in determining the benefits of PSK. The researchers also noted that patient reporting of side effects may have been influenced by their knowledge of taking PSK.
According to sellers, Chaga, a fungus that grows on birch trees and looks like burned charcoal, can prevent wrinkles, treat IBD, and fight bacterial and viral infections. Cordyceps militaris, also known as the “zombie fungus” and featured in the HBO show The Last of Us, is said to enhance exercise performance, have antidepressant effects, and increase female libido. However, there is no solid evidence from properly conducted clinical trials to support these claims.
According to UK legislation, it is not permitted to state that a food can prevent, treat, or cure any human disease. These types of claims are subject to regulations for medicines and must be granted marketing authorization by the Medicines and Healthcare Products Regulatory Agency (MHRA). An MHRA spokesperson confirmed that no marketing applications have been received for products containing lion’s mane, turkey tail, reishi, cordyceps, chaga, or shiitake mushrooms. Additionally, several retailers have been cautioned about making health claims for mushroom products and using the term “medicinal mushrooms”.
Medical medications are made from individual, thoroughly tested substances that are known to be safe and effective. However, supplements made from medicinal mushrooms can contain numerous different chemicals. The levels of these active compounds, which are responsible for the health benefits, can vary due to various factors such as cultivation age, growing conditions, and whether the extracts are from the mushroom’s fruiting bodies or its mycelia (root-like structures). Additionally, it can be difficult to determine the exact dosage contained in mushroom-based products. Testing has revealed that in some cases, the advertised species of fungi may not even be present in the product.
The majority of alleged health benefits attributed to mushrooms lack strong evidence from human trials. Despite this, even those who doubt their effectiveness recognize that the lack of evidence does not necessarily mean they are ineffective. Some medications, such as penicillin and cephalosporins (antibiotics) and lovastatin (cholesterol-lowering drug), are already derived from fungi and being used successfully. With the advancement of genome sequencing and techniques for extracting genetic information, there is hope that more of the vast array of compounds produced by fungi can be identified, purified, and administered in precise doses to treat various human illnesses.
According to Money, certain assertions about the healing properties of mushrooms are not backed by scientific evidence and are essentially worthless. However, he acknowledges that mushrooms do have complex chemical interactions with their surroundings and likely possess many valuable compounds. In his upcoming book, Molds, Mushrooms and Medicines, Money stresses the need for thorough scientific research to identify which compounds can truly aid in alleviating or curing human illnesses.