Where Do Your Functional Mushrooms Come From?
Eric Puro — Founder and CEO @ KAAPA, Executive Committee of the International Committee for Medicinal Mushrooms
Eric Puro is the CEO and Chairman of KAAPA Biotech, where he's scaling the EU's largest medicinal fungi factory to produce top-quality natural medicines. His career has spanned from corporate consulting in Chicago to building yoga studios in Portugal using only hand tools. Eric's diverse experiences include squatting in abandoned factories in London and embracing solitude in Oregon's remote woods. At his core, Eric is driven by a profound need to solve global issues by emulating best practices observed in nature.
Eric Puro challenges attendees to consider the origin of their medicinal mushroom supplements. He explains
We develop our immune system by an external response to our environment, and mushrooms are the same. When they are pushed to their limits, they develop the highest quality medicinal compounds.
Summary
- Mushrooms are biologically closer to humans than plants, sharing similar immune systems and producing compounds that the human body has specific receptors to synthesize and utilize.
- Cultivating mushrooms in overly sterile indoor environments with bleach and pesticides prevents them from developing the robust immune responses necessary for high-quality medicinal compounds.
- Growing mushrooms outdoors on natural substrates like Birch logs forces them to compete with other fungi, stimulating the production of more potent and diverse medicinal compounds.
- Utilizing original wood substrates rather than sterilized sawdust ensures that medicinal mushrooms receive the specific nutrient profiles they have evolved to consume over millions of years.
- Harsh climates and extreme purity in air and water, such as those found in Finland, provide the environmental stress required to push mushrooms to produce the highest quality medicinal outputs.
Article
Where Do Your Functional Mushrooms Come From?
Biology, Purity, And The Case For Outdoor Cultivation
At Biohacker Summit 2019 Helsinki, Eric Puro stood before a room full of self-optimisers and supplement users with a question that cut through the polished language of wellness branding: do you actually know where your medicinal mushrooms come from?
It was a simple provocation, but an effective one. Many hands had gone up when he asked who used functional mushroom supplements. Far fewer stayed raised when he asked who knew how those mushrooms had been grown. In that gap, between consumption and understanding, Puro located the central problem of a fast-growing industry: a market built on the promise of natural potency, yet often veiled in striking opacity.
Puro, the CEO and chairman of KAAPA Biotech, used his presentation, *Where Do Your Functional Mushrooms Come From?*, on Friday 1 November 2019 in Helsinki, Finland, to argue that the future of medicinal fungi depended not on cleaner laboratories or shinier extraction processes, but on something far older and harder to replicate: the intelligence of the natural environment.
A Kingdom Closer To Humans Than Plants
The foundation of Puro’s argument was biological. Mushrooms, he said, are more closely related to human beings than plants are. That fact was more than a curiosity. In his telling, it helped explain why medicinal fungi have become such an object of fascination in health circles.
“Our immune systems are very similar,” Puro told the audience. “The compounds these medicinal mushrooms create can be synthesized by us because we have receptors for those specific compounds.”
The point landed because it reframed mushrooms not as exotic plant-like supplements, but as organisms whose biochemical language may be unusually legible to the human body. In an industry crowded with vague promises and romanticised labels, Puro’s emphasis was on shared pathways, receptor compatibility and immune dialogue.
The Sterile Paradox
From there, he turned to a sharp critique of modern cultivation methods. Much of the medicinal mushroom supply, he said, was being produced indoors in highly controlled facilities, under conditions defined by sterilisation, filtered air, bleach and pesticides aimed at suppressing contamination.
To Puro, that level of control carried a hidden cost. Mushrooms, like humans, develop resilience in response to the world around them. Remove challenge, and you may also remove the very pressures that stimulate the production of valuable compounds.
He illustrated the point with an analogy drawn from human immunity: over-sanitised environments can weaken the natural education of an immune system. His claim was that fungi behaved in much the same way. A mushroom raised in clinical isolation may grow efficiently, but not necessarily optimally.
“When a mushroom is being attacked by mold and other fungi in the wild, it has to develop its immune system to hold off those attackers,” he said, “which results in the highest quality medicinal compounds for human use.”
It was the sort of claim that invited scrutiny, and Puro seemed to welcome that. Again and again, he returned to the need for data, insisting that the industry must justify its claims with evidence rather than folklore.
Why The Birch Log Matters
The most vivid part of the talk came when Puro described how KAAPA cultivated *Hericium erinaceus*, better known as lion’s mane. Rather than growing it on sterilised sawdust in laboratory conditions, the company used birch logs outdoors.
The distinction, for him, was profound. Mushrooms have spent millions of years evolving to consume dead wood, not nutrient guesses compacted into industrial substrate. To deny them that original food source, he argued, was to interrupt an ancient relationship between organism and environment.
“Mushrooms have been eating dead trees for millions of years,” Puro said. “They need their original substrate to produce the highest medicinal compounds, rather than sterilized sawdust where we are just guessing what nutrient profile they need.”
In this account, the birch log was not a quaint nod to tradition. It was a functional part of the medicinal equation, a substrate with ecological fidelity. Puro argued that outdoor-grown mushrooms on natural wood not only contained more of certain beneficial compounds, but also produced compounds absent from indoor-grown counterparts.
Finland As Stress Test And Sanctuary
If the substrate mattered, so did the setting. Puro painted Finland as an unusually powerful growing environment for medicinal fungi: severe, dark, clean and uncompromising. KAAPA’s farm, he said, lay about an hour west of the summit venue, where ten thousand logs sat beneath the shade of spruce and pine.
In another industry, harshness might be a drawback. Here, it became an asset.
Finland’s long winters, extended darkness and cold conditions, Puro argued, pushed mushrooms into deeper adaptation. Stress, in this formulation, was not damage but stimulus. The fungi were “pushed to their limits”, and in doing so were compelled to produce stronger defensive chemistry.
“Not only does growing outdoors make a difference, but the purity of the environment matters,” he said. “In a harsh climate like Finland, mushrooms are pushed to their limits in the best quality air and water ever measured in history.”
That pairing of hardship and purity formed the emotional core of the presentation. Finland was framed as both crucible and sanctuary, a place severe enough to provoke biological strength and clean enough to avoid contamination by the industrial world.
Transparency In A Booming Industry
What Puro was really calling for, beneath the mushroom biology and cultivation details, was transparency. Consumers, he suggested, should not be satisfied with a capsule label that says “lion’s mane” or “reishi” without revealing origin, substrate or method.
As the medicinal mushroom market expanded, he warned, it would become even more important to distinguish between products that merely borrowed the language of nature and those that had actually been shaped by it.
“As the medicinal mushroom industry grows, it is vital that we back what we say with data,” he said. “We will grow mushrooms in whatever way is best to ensure we are providing the most effective and potent medicinal compounds for you.”
That final note was telling. Puro did not present himself as a purist for tradition’s sake. His case was not that outdoor cultivation was morally superior, but that it was, based on the evidence he cited, biologically superior. If a better method emerged, he implied, the obligation would be to follow the science.
The Deeper Question In Every Supplement Bottle
By the end of the session, the talk had done more than promote a cultivation philosophy. It had widened a question many supplement users rarely ask: not just what is in the bottle, but what kind of world produced it.
Puro’s message at Biohacker Summit 2019 Helsinki was ultimately about relationships: between fungi and forests, between stress and strength, between biological kinship and medicinal effect. In an era obsessed with optimisation, he offered a reminder that some of the most potent systems are not engineered into sterility, but forged in contact with competition, climate and time.
The functional mushroom boom has often sold itself through sleek packaging and broad claims. Puro’s intervention was to insist that origin matters, purity matters, and growing conditions matter. For anyone swallowing these supplements in search of sharper cognition or stronger immunity, that may be the most important biohack of all: to ask where the mushroom came from before asking what it can do for you.
Part of Biohacker Summit 2019 Helsinki