The ancient wisdom of chaga: Finland's mushroom guru shares forest biohacking secrets

Medicinal mushroom expert reveals how a birch tree parasite could hold keys to longevity at European wellness summit

At the cutting edge of the biohacking movement, beyond the realms of supplements and devices, lies an unassuming black growth found on birch trees across the northern hemisphere. Jaakko Halmetoja, Finland's leading chaga expert, captivated attendees at the HOLOLIFE Summit 2025 Europe in Tallinn last Friday with his presentation "Chaga intelligence: Biohacking with the Wisdom of the Woods."

"I believe the organisms we have the longest relationships with are the ones that eventually show us what we need for our evolution," Halmetoja told a packed audience at the Estonian wellness gathering. Drawing on nearly two decades of research and personal experimentation, he unveiled how this ancient fungus represents a bridge between traditional wisdom and modern science.

Not just another mushroom

Halmetoja was quick to clarify a common misconception. "What we use isn't actually the mushroom itself," he explained. "It's a growth produced by the actual organism living inside the host tree, typically taking 7 to 11 years to develop."

This dark, charcoal-like conk has a fascinating relationship with birch trees. The fungus consumes the tree's lignins and concentrates beneficial compounds like betulinic acid from the bark – substances independently studied for their medicinal properties.

"Chaga is almost like a bridge between trees and the fungal kingdom," Halmetoja said. "It has taught me about trees more than about mushrooms themselves."

From fire starter to cancer fighter

Long before its medicinal properties were recognized, chaga served a crucial practical purpose across northern regions of Europe, Asia and North America. Known as "true tinder fungus," it was used for thousands of years to carry fire – a vital technology before the invention of matches.

Its medicinal use entered Western awareness largely through Russian literature. Halmetoja highlighted Alexander Solzhenitsyn's semi-autobiographical novel "Cancer Ward," which noted observations of cancer-free populations in regions where people regularly consumed chaga tea for economic reasons.

"In the 1950s, the Russian Academy of Sciences formulated a product sold as a medicine – a chaga extract with some cobalt chloride," Halmetoja revealed. "This was used successfully for treating psoriasis and similar autoimmune skin disorders."

Science behind the tradition

The presentation delved into chaga's dual bioactive components: water-soluble polysaccharides in its interior that function as prebiotics supporting immune health, and fat-soluble compounds on its surface with antiviral and anti-cancer properties.

"The main areas where I use chaga myself these days – not just prophylactically for my immune system, but after a meal, a cup of chaga tea to balance everything out, lower inflammation in the gut, stabilize blood sugar," said Halmetoja.

He referenced preliminary clinical data linking chaga to improved mitochondrial function and stem cell activation, highlighting its traditional association with longevity. The mushroom also contains ergosterol, a precursor to vitamin D2, which increases significantly when exposed to sunlight.

Traditional wisdom in modern context

Drawing on Chinese medicine principles, Halmetoja explained how chaga fits into traditional understandings of health and longevity.

"One of the themes here is longevity: You have the candle – that's basically the stem cells, the potential you get from your parents. To increase the Jing, you need to internalize substances – you can't increase it through energetic practice alone," he said, relating this concept to modern understanding of cellular rejuvenation.

This perspective frames chaga consumption as an investment in future resilience: "I like the idea that you consume these herbs and bury them as a treasure – when you need it, you have the resources and capacity there."

From forest to kitchen

Perhaps most striking was Halmetoja's emphasis on incorporating chaga into everyday life through "medicinal cooking" rather than just consuming it as a supplement.

"Many medicinal mushrooms support blood sugar regulation, immune function, and reduce gut inflammation, making them valuable for overall health," he explained.

His culinary suggestions included using chaga decoction as a base for coffee, salad dressings, soups, and drinks. "Let food be thy medicine and medicine be thy food," he reminded the audience, citing Hippocrates' ancient wisdom.

For those interested in harvesting their own, Halmetoja noted that Estonia's forests provide ample opportunity. He emphasized sustainable harvesting practices and the value of connecting directly with these natural resources.

The importance of consistency

Throughout his talk, Halmetoja repeatedly emphasized one fundamental principle: "Consuming tonic herbs daily is essential—you must take the herbs regularly to truly benefit from their medicinal properties."

This approach has guided his own practice for nearly two decades. "That's why I've been consuming chaga for nearly twenty years, more or less daily, as a source of 'more battery' for life and longevity," he shared.

The HOLOLIFE Summit 2025 Europe continues through Sunday in Tallinn, bringing together experts in wellness, biohacking, and holistic health from across the continent and beyond.

Frequently asked questions

Is chaga actually a mushroom?

Not the part people use. Jaakko Halmetoja explained that what is harvested is a growth produced by the organism living inside the host tree, typically taking 7 to 11 years to develop. The fungus consumes the tree's lignins and concentrates compounds such as betulinic acid from the birch bark.

What was chaga used for before medicine?

It was known as true tinder fungus and used for thousands of years across northern Europe, Asia and North America to carry fire, a vital technology before matches. Its medicinal reputation reached Western readers largely through Russian literature, including Alexander Solzhenitsyn's semi-autobiographical work.

What are chaga's active components?

Halmetoja described two groups: water-soluble polysaccharides in the interior that act as prebiotics supporting immune health, and fat-soluble compounds on the surface with antiviral and anti-cancer properties. He uses it both for immune support and after a meal, as a tea to lower inflammation.

About the event

This recap is part of the HOLOLIFE Summit 2025 Europe series, recorded in Tallinn on 14 and 15 June 2025. Read the summary of the whole event or join the next edition, HOLOLIFE Summit 2026 Amsterdam, on 14 and 15 November 2026.