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Q: Dear Superfoodly, do so-called medicinal mushrooms like reishi, lion’s mane, chaga, and turkey tail possess any anti-viral properties? Can mushrooms help fight coronavirus?
A: There is a lot of false information and scams surrounding the COVID-19 pandemic. Whether you’re talking common food forms like white button and shiitake, or herbal supplement forms like reishi and chaga, none of these – nor any other type – can kill viruses.
Whether it’s influenza, a type of coronavirus (of which COVID-19 is one), or any other type of viral infection, eating mushrooms or taking supplements made from them will NOT protect, treat, or cure you.
How the mushrooms for coronavirus myth started
Research does not suggest that any type of mushroom can actively kill or destroy viruses. In other words, they’re not antiviral.
Separate from that, many species of fungi appear to have immunomodulating properties. They work in two ways (1):
1. Stimulating production of immune effector cells
Those include lymphocytes, macrophages, and natural killer (NK) cells.
In turn, that results in the body ramping up production of cytokines, including interferon gamma (INF)-γ, tumor necrosis factor alpha (TNF)-α, and interleukins (ILs).
Or in plain English, boosting the immune system.
2. Mitogenicity
A mitogen is a small protein or peptide that triggers a cell to begin division (mitosis).
Anti-viral research
The immunostimulating effects have been studied in the lab, but research in living bodies (e.g. humans) is lacking.
For example, below is a table from a lab study where various mushroom extracts were used on cultured cells infected with a H1N1 influenza strain and a herpes simplex virus type 2 strain.
Compared to the untreated control cells (bottom line at 6.0), you can see how much lower the number was (indicating lower infectivity) in the cells treated with various mushroom extracts.
Species like Pleurotus eryngii and Schizophyllum commune on that list are uncommon. Others are quite common, including the best performing which was turkey tail mushroom (Trametes versicolor).
Other common species ranking well in this study included reishi (Ganoderma lucidum) and enokitake (Flammulina velutipes). The latter is well-known in Japanese cuisine. (2)
How these immunostimulating effects help or harm the body’s ability to fight an infection remains to be clinically proven. Anyone who claims mushrooms can help prevent or treat coronavirus are lying, as no mushroom has been studied for COVID-19 in any way, shape, or form.
What has been clinically proven?
Specific compounds extracted from mushrooms have been clinically proven in human trials for certain cancer treatments.
Polysaccharide-K (PSK) or krestin is not an approved cancer treatment in the United States, but it is approved in Japan. Although less commonly used these days, in the 1980’s it represented over 25% of sales for cancer medicines in that country. The active ingredient of PSK is extracted from turkey tail mushrooms. (3) (4)
The takeaway?
Certain species of fungi have been studied extensively for the benefit of increasing immune system response. This might be useful in a number of diseases. However, none have been studied in humans for viral infections.
Any website or social media post you see claiming proof of mushrooms for COVID-19 is spreading a myth, or an outright lie.
It is theoretically possible that some species might stimulate the body’s innate immune system to help combat certain types of viruses, but as of today, that is only theoretical. They may not help at all. In fact, they could make things worse.
Sometimes ramping up the immune system is bad, such as for autoimmune diseases (where aspects of the body’s immune system is too active to begin with).
For these reasons, you should not take mushroom supplements for any infection or disease. Much more research needs to be done.
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.