Why Our Journey Through The World’s Living Pharmacy Matters To You

As a surgeon, I lived daily the interconnections of planetary health and human health as I transplanted hearts and lungs, giving life to people who would otherwise have died. It was cyclosporine, a miraculous drug derived from a fungus found in nature, that made all these transplants possible.

I’ve always been fascinated by the incredible ways nature and science work together to heal the human body. In my dad’s early medical-practice days back in the 1930s, he in fact had to rely primarily on nature to heal most of the maladies his patients presented with. He simply didn’t have the vast pharmaceutical armamentarium I had, coming along a generation later.

I thought about this as my wife, Tracy, and I began our guided hike deep in the Amazon rainforest (Tapajós National Forest) with colleagues from The Nature Conservancy (TNC). At the outset we had been given a choice: join a group that would cover a longer, more intense, 10-kilometer trek through the dense rainforest, or take a shorter hike with a traditional guide who promised to stop frequently and share the secrets of the trees and plants and insects around us. Tracy and I chose the latter, opting for depth over bragging rights of distance. And it was a decision that expanded the way I think about the powerful connectedness of planetary health with our own human health. Nature is about us.

Our guide grew up in the rainforest; it was his world. We began down a narrow, winding trail, our local guide opening with a disheartening description of how, not too far away, deforestation had so dramatically affected his community of people and destroyed not only his way of life but the richness of the soil, the range of foods he eats, the way he treats illness, and the water he drinks — and everything that we were about to experience. His mood brightened as we followed the path, now entering a tunnel into the old growth forest, the towering, magical green canopy enveloping us.

Knowing I was a medical scientist, he said that we would be stopping often to discuss plants and trees with medicinal properties—plants that his local communities have used for generations to heal and thrive. The air was thick with humidity, and the forest seemed alive with sounds — colorful birds, darting insects, cutting ants, and the frequent rustle of something unseen. Senses come alive.

Our first stop was at an inconspicuous tree, the global impact of which I recognized at once as he began to tell the story. It was the Cinchona tree. Its bark, he explained, contains quinine—what became the first effective treatment for malaria. For centuries, indigenous peoples used it to combat fevers, and later, it became the foundation for modern antimalarial drugs. It literally revolutionized medicine globally and it continues to inspire modern malaria treatments. As a physician who has cared for many patients with this debilitating and deadly disease in Africa, I couldn’t help but marvel at how this one tree has saved millions upon millions of lives, most of them children, around the globe.

Early on in the hike, the rain began to fall. When it was clear it would not pass lightly, we pulled out bright blue ponchos thoughtfully provided by our TNC team, laughing a s the droplets cascaded through the leaves above us. Our guide paused to show us how living in the forest, they would find specific hanging vines to collect water to drink. And as the rain cooled the air, we pressed on, stopping to learn more about the incredible medicinal treasures this rainforest holds.

Our journey continues for another 20 minutes, when our teacher leads us off the path to a tree dripping with red sap, known locally as Sangre de Drago, or “dragon’s blood.” He pulled his long machete from its aged leather sheath and deftly cut into the bark. The sap oozed out like liquid ruby. Indigenous and traditional peoples apply it to wounds to promote healing of cuts and abrasions and to prevent infection. Modern science has since confirmed its robust antimicrobial and anti-inflammatory properties, and today it’s being studied for many pharmaceutical applications.

We stopped at a natural pool of water, collected from a swift, narrow stream threading through the dense undergrowth, where we had planned a quick swim. But our group opted to keep hiking due to the now heavy rain. And a hunger to learn more.

A little farther down the trail, our guide stopped to show us a climbing vine he called Cat’s Claw. As we crowded around, he explained how this plant is routinely used to treat inflammation, such as painful wrists and ankles (arthritis), and how it strengthens the body (the immune system we know today) to prevent infection. Modern day researchers are exploring its potential to fight cancer. This vine growing quietly in the Amazon may one day help us tackle some of the most difficult diseases of our time.

Our trek was not all about medicinal properties — we learned a bit of nutrition as well. Our guide showed us how to eat grubs (gongo, in Portuguese). Cracking in half a nut from a tucumã palm, he showed us a large grayish grub curled up in the middle of the inner coconut-like, white contents. One by one each of us, some more reluctantly than others, pinched out a grub and swallowed it whole. Our guide tried to make us feel a bit better by telling us grubs are regarded as a nutrient-dense, delicacy in the Amazon region, adding they are a symbol of the deep connection between indigenous cultures and their environment.

A little further on we came upon the majestic Copaiba tree. Our guide pointed out the resin that seeps out of its trunk has powerful anti-inflammatory and pain-relieving properties. Locals, he added, use it for everything from bee stings to skin rashes to a variety of respiratory and throat ailments. I had only recently been reading about scientists now studying this resin for its potential to treat cancer—a reminder of how much we still have to learn from nature, and how important it is for to conserve the biodiversity that makes such discovery possible.

As we continue our immersive journey walking in awe, all of this begins to make sense to me. Why are all these fascinating medical discoveries here in the forest? I did not learn any of this in medical school. It took a walk in nature. The earth has been around approximately 4.5 billion years; we as human beings (homo sapiens) a mere 300,000 years. Nature (complex multicellular life) has been running its own scientific experiments through evolution for more than 600 million years; trees have been evolving for over 385 million years. That’s a lot of time to improve in nature’s laboratory.

We learned about mental health. At about the halfway point of our trek, we stopped at a woody, climbing-vine plant with deep cultural significance: Ayahuasca. Frequently used in spiritual ceremonies, the extract has psychotropic properties. It was used in traditional ceremonies for mental healing and emotional wellbeing. Ayahuasca is now being scientifically studied for its ability to treat a range of mental conditions including depression, Post Traumatic Stress Disorder, and addiction. Imagine: a plant that has been part of indigenous healing and spiritual practices for centuries may hold answers to some of the most pressing mental health challenges we face today.

And we learned so much more along the way. He pointed out the towering Lapacho tree, whose bark is brewed into a tea (called “pau d’arco”) that boosts the immune system and fights infections — a natural antibiotic. And he showed us the Andiroba tree, rubbing the leaves vigorously between his hands to produce an oil that soothes insect bites (we carefully stepped over the trails of the extremely painful red ants that would regularly cross our path) and protects against vector-borne diseases.

Again, with his machete, he artfully cracked open the double-shelled Brazil nut. He explained the benefits of the Brazil Nut tree, not just for its nutritious nuts but more specifically for its high content of selenium, an essential mineral micronutrient for humans and animals, which in particular supports thyroid health. We now know it has strong immune-boosting and antioxidant properties, linked to reducing the risk of chronic diseases like cancer and cardiovascular diseases.

And then there was the Guaraná plant, a natural energy booster found in many of the local drinks we consumed over the course of our travels across Brazil. Rich in caffeine and antioxidants, it is consumed for stimulating mental alertness. And we came across the Uña de Gato vine, a close cousin of Cat’s Claw, used to treat arthritis and immune disorders.

The Amazon is home to thousands of plants with medicinal properties, many of which we have yet to discover. We have just scratched the surface. Indigenous peoples have been stewards of this knowledge for centuries. As we hiked back through the rainforest, I couldn’t help but think about how much our human health and wellbeing owe this biodiversity. Planetary health and human health. It’s why The Nature Conservancy has named the Amazon region as one its four most significant focal areas globally (another is Appalachia right here at home) to address the changing climate and biodiversity loss. The Amazon is not just a rainforest—it’s a lifeline, a source of healing for both the human body and the planet.

But this lifeline is under threat.

The changing climate and accelerating deforestation are putting this rich biodiversity—and the knowledge of the people who live here—at risk. If we lose the Amazon, as we learned in our trek today, we lose more than the forest and nature-based solutions to the changing climate; we also lose potential cures we haven’t even identified yet.

A healthy planet is essential for healthy people. The Amazon regulates our climate, purifies our air, produces oxygen, and stores carbon, but it also holds secrets that can save lives. Protecting this rainforest is not just an environmental issue—it’s a human health issue, and I believe a moral issue.

Tracy and I came away from this journey with a profound sense of responsibility—not just as visitors to this incredible place, but as energized advocates for its preservation. We see, as we hope you will, the Amazon not just as a faraway forest, but as a vital part of our shared future.

Let us work together to protect the Amazon, to honor its gifts, and to ensure that its wonders endure for generations to come.

____

Join us in making a difference! To learn how we’re partnering globally to protect, restore, and sustainably manage forests, click here: https://nature.ly/436tMdt