There is an ongoing debate in the medicinal/functional mushroom world about the use of the mushroom fruiting body versus the use of mycelium. Some say to use only the former, while others, especially the producers and sellers in the USA, swear by mycelium.

Which is then the best option when making medicinal mushroom supplements or using them in functional foods?

Let’s find that out! In this article we’re going to explain what are mushroom mycelium and fruiting body, their differences as well as their advantages and disadvantages.

What is mushroom mycelium?

Mycelium is the mushroom’s root system that lives mostly underground. It can grow to hundreds even if not thousands of cubic meters in size, and as old as well. The mycelium is also called the “vegetative body” and its job is to keep the mushroom alive. It absorbs nutrients and water from the ground or the material its growing on, usually referred as substrate.

Mushroom mycelium made for commercial use is often grown in a lab in a medium consisting of most often a grain such as rice. This allows for a more controlled, hygienic, and faster way of growing the mycelium.

In the lab the mycelium is let to “sit” in this substrate for a certain period. During this time the mycelium will ferment the substrate. As the mycelium will become intertwined with this substrate it’s growing on, it’s impossible to separate the two. So, the whole mass will be dried to be then processed further to e.g. mushroom extract.

What is a mushroom fruiting body?

The fruiting body is what most people think of when they think of a mushroom. It’s the part of the mushroom that can be seen and eaten above ground in the case of edible mushrooms.

The fruiting body is basically the reproductive organ of the mushroom. Its “job” is to release spores from which new mushrooms can grow into mycelium and start the growth cycle all over again.

Because the fruiting body is exposed to the elements, is smaller in size, and has a different function than the mycelium, it has a different composition of ingredients as well.

What are the differences in ingredients between the fruiting body and the mycelium?

Mycelium and fruiting bodies contain many of the same ingredients, but in different compositions. This is crucial when it comes to their use as supplements.

Studies and analyses have shown that the fruiting body contains more polysaccharides and beta-glucans than the mycelium. The mycelium also has them, but significantly less. Some ingredients, such as triterpenoids found in e.g. reishi and chaga, are technically found only in the fruiting body.

The fruiting body can be thought of as a more condensed form of the mycelium. More of the same ingredients, but in a tighter package.

However, mycelium is not useless. Research has also concluded that mycelium contains more vitamin D and some vital compounds such as ergosterol and lovastatin. Lovastatin may help reduce the risk of cardiovascular death and ergosterol may help prevent diabetes. Also, a study comparing the neuroprotective effects of lion’s mane fruiting body and mycelium could conclude that the mycelium seems to be more effective in protecting nerve cells than the fruiting body.

So, mycelium has its uses. It’s even been studied as a meat substitute, a new type of packaging solution, and even a building material. However, using it as a supplement has some question marks.

What are the differences between mushroom products made from fruiting bodies or mycelium?

As mentioned above, medicinal mushrooms are interesting as dietary supplements and functional foods because of polysaccharides and beta-glucans. They are the bioactive components behind the mushrooms’ ability to boost the immune system, reduce stress, and increase concentration, to name a few.

Therefore, products made from the fruiting body alone are more potent than those made from the mycelium due to a higher concentration of polysaccharides and beta-glucans.

Of course, you might ask, if the mycelium still seems to contain many other vital components with potential health benefits, why not just make a product out of both the mycelium and the fruiting body?

It’s not a bad idea, and it’s being done by a number of companies, especially in the US and UK. Unfortunately, the final product is not necessarily just the best version of both parts of the mushroom.

Why we won’t recommend using mycelium in medicinal mushroom products

If mycelium is used, it will mean that the end product will not be made of 100% of mushroom alone.

As mentioned above, many producers grow their mushrooms and/or mycelium on grains such as rice, corn, or oats. And it’s rather impossible to separate the mycelium from its growing medium. So both of them will processed into a mushroom powder or extract. The end result is therefore a mix of mushroom and whatever growing material was used, instead of a 100% mushroom product.

Another problem with growing medicinal mycelium on grains such as rice or oats is that they contain mostly alpha-glutens or a-glutens, or non-mushroom-specific beta-glucans. When these get mixed into the final product, it can contain significantly more alpha-glucans and other beta-glucans than mushroom-specific beta-glucans.

Many tests used to measure polysaccharide or beta-glucan content can’t separate these different types of polysaccharides and beta-glucans. So what appears to be high in polysaccharides may actually be high in alpha-glucans.

The end result: a less effective mushroom product. Or, well, not really a mushroom product, but a mixture of several starchy ingredients, one of which is a mushroom.

Reasons for producing mushroom products from mycelium

With all this information, why would anyone want to produce a less effective mushroom product? The answer, of course, is money. Mycelium products are cheaper to produce than products made from the fruiting body alone.

By using both the mycelium and the substrate, the producer gets a larger mass to turn into extract. You can also grow mycelium much faster than a fruiting body, so it’s also just, well, faster to produce mycelium products.

A larger amount of raw material in a faster timeframe usually means cheaper prices. However, these cheaper products come at a cost: they’re not as effective.

The truth that many don’t want to accept is that high quality medicinal mushroom raw materials or products that are effective are not cheap.

Unfortunately, it’s not always clear how to identify a quality product made from the fruiting body alone, thanks to a lack of government guidelines or some rather confusing marketing tactics done by mushroom companies.

How businesses and consumers can make informed choices about available medicinal mushroom products

How can companies and consumers alike be sure they are getting a truly effective medicinal mushroom product?

Depending on the country, it may not be that simple.

In the EU, it’s not allowed to sell or market medicinal mushroom products consisting of mycelium because it’s considered a Novel Food.

Some companies try to get around this rule by using both the mycelium and the fruiting body and labeling it as a “full-spectrum” product. Other popular terms for a blended product are “extracellular matrix”, “full life cycle”, or even “complete fungus”.

Most of these companies won’t explain what the ratio of mycelium to fruiting body is. Is it 50-50? 30-70? Or even 80-20?

In the US, the Food and Drug Administration (FDA) allows the sale and marketing of mycelium products, but requires that mushroom products are clearly labeled as to which part of the mushroom they contain. Unfortunately, the FDA can’t really enforce this rule. Therefore, companies can use suspicious marketing tactics and claims to try to convince consumers.

Companies and consumers need to be vigilant when purchasing mushroom products. They need to research what language the company uses when talking about their products. Do they mostly refer to the fruiting body or the mycelium in a positive way? Do they have an organic certificate for their products or raw materials?

It is very important to purchase mushroom products from companies that have an organic certificate from a reputable source. Mushrooms absorb everything from the substrate they grow on, so it’s important that the producer doesn’t use pesticides or contaminate the water or substrate.

Pricing is also usually a relatively good indicator. As we’ve said before and will continue saying: a high quality medicinal mushroom raw material made from pure fruiting bodies is not cheap.

Of course, there are other cost factors than just the raw materials. But buying the cheapest is not the way to go with medicinal mushrooms if you are looking for the most effective and safest product possible.

Conclusion

As said, we do not recommend that companies or consumers purchase medicinal mushroom products that consist of both mycelium and fruiting bodies.

Although mycelium is not without some advantages, growing it without adding a lot of other materials to the final product is rather impossible. Or so cost and time intensive that it’s simply not commercially feasible.

That’s why we don’t believe that any of the mixed or “full spectrum” products on the market today can be as effective as a medicinal mushroom product made from pure fruiting bodies. And because we only want to offer the most effective products possible, we have chosen to only use the fruiting body in our medicinal mushroom raw materials. (The exception is Cordyceps, which really can’t be commercially harvested from the wild).

We hope that we managed to explain the differences between mushroom mycelium or fruiting body, so that you can make an informed decision about which is best for your needs.

If you’re interested in learning more about the quality factors of medicinal mushrooms, you can read this article.

Sources

• Berger RG, Bordewick S, Krahe NK, Ersoy F. Mycelium vs. Fruiting Bodies of Edible Fungi-A Comparison of Metabolites. Microorganisms. 2022 Jul 8;10(7):1379. doi: 10.3390/microorganisms10071379. PMID: 35889098; PMCID: PMC9315710.
• Nammex.com
• Sun SK, Ho CY, Yen WY, Chen SD. Effect of Water and Ethanol Extracts from Hericium erinaceus Solid-State Fermented Wheat Product on the Protection and Repair of Brain Cells in Zebrafish Embryos. Molecules. 2021 May 30;26(11):3297. doi: 10.3390/molecules26113297. PMID: 34070878; PMCID: PMC8198590.