[A shortened version of this article first appeared on Leafly]
For Homo sapiens, like most species, surviving life on Earth isn’t exactly easy. But thankfully, and importantly, we’re not in it alone.
For thousands of years, modern humans have been developing mutually beneficial relationships with other species, from dogs and cats to bacteria and breadfruit. These interactions have allowed our different life forms to evolve and flourish together, and even cross the globe. These relationships are examples of ‘mutualistic’ coevolution, which happens when multiple species affect each other’s progress for the better over time.
They’re also a key part of what physician, medical geographer, and AIMS Institute co-founder Dr. Sunil K. Aggarwal calls humankind’s “evolutionary garden” — the collection of plants, fungi, and animal secretions that people have cultivated since prehistory, and carried around the world, because of their particular usefulness for human health and survival as food, medicine, clothing, or other vital supplies.
Most are still embraced today, from honey and grains to caffeine and aspirin. In the past century, however, some cultures have decided it’s a good idea to cordon off certain areas of that garden, despite a long evolutionary history — and current scientific data — saying otherwise.
These blacklisted species include plants and fungi that humans have carefully administered for millennia to treat some of our worst sicknesses and pain, of both body and mind: distilled opium plants for physical agony, for example, or psilocybin tea for processing some of life’s most difficult moments. Many are powerful, and can even be dangerous (in classic or modern forms) without supervision. Some have multiple uses, but never caught on in certain cultures.
According to Aggarwal, however, and to a growing number of experts on history and biology, one forbidden species stands out as our biggest loss, and for likely being the single most useful plant that humans have ever gotten to know (which may even have made us ‘more human’).
That plant, of course, is cannabis.
Humans & Cannabis 101: From early life to the Himalayas
Current research indicates that humans have been cultivating cannabis for tens of thousands of years, but aspects of our biology suggest that the relationship reaches back much further.
As a medical geographer, Aggarwal has studied the path of numerous natural medicines in different cultures and around the globe, based on anthropological and archaeological evidence. One of the oldest on record is cannabis, he says: it’s been evolving across this planet for tens of millions of years, stemming from its sturdy ancestors in Central Asia. In fact, early cannabis seems to trace back to when the world’s tallest mountain range, the Himalayas, were forming.
“Sixty million years ago, those mountains were formed by the Indian subcontinent hitting the Asian plate,” Aggarwal explained in a phone interview. “All life there had to adapt or die.”
“It created a unique opportunity for this ancestral plant, which appeared 40 to 50 million years ago, to become very active in production,” he said. “There was less oxygen, and increased UV radiation, so the plant had to develop quite a bit of hardiness.”
In the millions of years since, cannabis has shown it’s able to survive in a fairly wide variety of climates, and thrive in many of them (from scrub-like Cannabis ruderalis to tall-growing Cannabis sativa and bush-like Cannabis indica, which produces most of our cannabis flower and low-THC hemp today, typically in hybrid form).
It also appears to have been distinctly chemically compatible with the brains of animals such as humans for much of that time.
In response to its new, harsher environs near the Himalayas, Aggarwal said, the plant seemingly began to produce a wide range of terpenes and cannabinoid chemicals, which the human body — with its balance-keeping endocannabinoid system, which relies on cannabinoid neuroreceptors throughout the body, and can be found in all vertebrate species — is especially suited to process.
Some cannabinoid producers are better than others
The endocannabinoid system is key to our overall health and wellness because it has a crucial role in regulating some of our major biological functions. At all times, our bodies are trying to maintain a narrow operative balance, known as “homeostasis,” and cannabinoid compounds can trigger the endocannabinoid system to regain this important equilibrium throughout the body as needed.
Despite their name, cannabinoid chemicals aren’t unique to cannabis. Chemicals that stimulate the endocannabinoid system can be found in many other plants, like echinacea, turmeric, and kava, to name a few, and may even have structural similarities to the compound type CBG, from which all phytocannabinoid compounds are derived (i.e. the ones that aren’t formed inside an animal’s body, including CBD, THCA, CBC, and many more).
But cannabis “robustly produces tons of them,” Aggarwal said. As a result, “People living near the Tibetan Plateau domesticated the plant early on and found a great number of uses. That includes good old nutrition, and fibers for cordage, as well as the neurological side, which is very interesting.”
“It affects our neurological circuits and has a very important role in protecting the brain from injury, and promoting feelings of relaxation,” Aggarwal explained. “Physical and psychological trauma can disturb the brain, and suboptimize it; the endocannabinoid system, and phytocannabinoids if need be, can set the brain on the path toward regeneration.”
In short, Aggarwal said, “This cannabis ancestor happened to make these compounds that bind to receptors in the human system which tap into an even older evolutionarily evolved biological system, which goes back 600 million years: a magnitude older in terms of stages of the formation of life.”
Specifically, those receptor types — known as CB1 and CB2 today — trace to “when multicellular organisms were becoming multicellular, and were trying to figure out how to send communication and modulate action,” Aggarwal said. “In biogenetic mapping, when you look at different species and map how old they are, you find cannabinoid receptors going back, and through today. In Homo sapiens, it’s a really integrated system for cell communication.”
On the cellular level, cannabinoids are also particularly useful for their anti-inflammatory and antioxidant properties, throughout the body as well as the brain. These aspects help the body to maintain optimal performance across its systems from the intercellular level on up, like other natural supplements that ease the way for the body to do its job.
“In terms of their antioxidant properties and neuroprotective properties, cannabinoids are certainly not the only game in town,” Aggarwal said. “But they’re pretty high up there.”
History’s “useful” plant goes global, shaping culture and religion
Aside from archaeological and biological evidence, humankind’s relationship with cannabis can be seen in thousands of years of documentation on the plant, and oral histories that reach back even further. As Aggarwal wrote in 2013, “Cannabis’s very name belies its longstanding relationship with humanity, as it was pragmatically given the species name ‘Sativa’ in 1542 by German physician-botanist Leonhart Fuchs, meaning ‘cultivated’ or ‘useful’ in Latin.”
Researcher Robert C. Clarke, who’s written or co-authored numerous texts on cannabis’ history and biology, said in a phone interview that, simply put, cannabis seems to be the most useful plant that humans have ever come across. “Plenty of plants are used for one purpose, and I can name a number of plants that are used for two purposes,” he said. “But I can’t think of another one that’s used for three.”
For example, “Palms provide us with food, and with fibers for clothing or shelter; bamboo is the same,” he said. Others provide us with “both food and drugs,” such as numerous fruits, roots, and grains that people have long eaten but also fermented into alcohol.
But cannabis has all three, Clarke said: “Food, fiber, and drugs.” Meaning that, from just one kind of crop, humans can get an important source of protein and essential fatty acids, fiber for building and crafting, and medical or cultural tools for our minds and bodies.
Researchers are still exploring why cannabis has come to produce different chemicals, including THCA, which turns into THC over time or with heat, and can get us high. The prevailing theories are that THCA is produced as a protective measure, either to deter insects or other predators, as an antimicrobial agent to guard plants from disease, or as a human attractant, assuring its spread worldwide.
Clarke said that humans were probably “really first looking for food” when they approached cannabis. “The value of that fiber would be apparent, too, whether it’s easy to work with or not,” he said.
“But as soon as you got those sticky resins all over your fingers, I’m sure the psychoactive experience wasn’t far behind.” In fact, he said, “I reckon it coevolved with us most profoundly on the psychoactive level. Almost every society has used it and many have involved it in their religious practices.”
In India, for example, in the Vedic tradition it’s been considered one of five sacred plants for thousands of years, and used in spiritual contexts for pleasure, mental liberation, and to honor gods, among other things. In ancient China and Central Asia, Taoist records note the plant’s hallucinogenic properties, and its ability to help mentally approach the divine. It’s also played a role in the spiritual or cultural practices of groups across the Middle East, Africa, Europe, and South America, among other places.
For now, Clarke said, it’s unclear whether residents of ancient Japan were “dosing” cannabis or just using it for general nutrition as indicated by archaeological seed remains. “But when you look at examples of really intricate Jomon pottery, you wonder what drugs they were on.”
It even seems possible that cannabis helped to kickstart our evolution into the big-brained, culture-prone critical thinkers that we are today, according to some researchers. This could have occurred for practical, nutritional, or psychoactive reasons, or (like the plant itself) as a mixture, but we may never know exactly how things changed when humans started using cannabis and other entheogens, or just how they did it.
“We can only speculate how people first discovered cannabis’ psychoactive aspects,” said Martin Lee, co-founder and director of Project CBD and the author of several books on cannabis, in a phone interview. “It’s hard to imagine it happened [through] eating, but for various reasons you can imagine that they inhaled smoke accidentally.”
Regarding humans’ neurological development and nutrition, Lee said, “Agriculture is really a turning point as the beginning of hoarding and carbohydrate farming, which was different from earlier diets.” He continued, “It’s possible that cannabis is the first agricultural plant; it’s certainly one of the very, very early ones, and cannabis is unique because it’s so versatile.”
Cannabis uplifts the downtrodden, makes money, and gets banned anyway
Like other drugs tied to spiritual and cultural practices, cannabis has often been used in different cultures in a social context, but also a solo or one-on-one basis. Sometimes it’s used for celebration and relaxation, and other times for guided introspection, and even dealing with some of life’s hardest moments and realities, from young adulthood and depression to mortality.
Dr. Uma Dhanabalan, a Massachusetts-based physician and advocate whose practice includes cannabis medicine, commented to Leafly in 2019, “I’m originally from India, where it’s considered a divine gift from the gods with a sacred angel that lives in it” — one which helps people cope with fear and anxiety, and find joy.
On a biological level, stimulating the endocannabinoid system is part of our bodies’ toolkit for social navigation and balance. Experimental studies have shown that when you boost the body’s endocannabinoid system, people feel the emotional impacts of rejection less, Aggarwal said.
Lee explained that plants, like humans, have ways of dealing with stressors, and expressing that stress physically. “Cannabis plants do it through chemical signals, odors, things like that, and plants under stress — if they’re being eaten by insects or whatever — have evolved to communicate with their environment to deal with those stressors.”
“They might have a smell that attracts a predator of the thing attacking the plant, or that will keep potential predators away,” Lee said. “And it so happens that these same smells, the same molecules that [cannabis] uses to deal with stress, are very helpful to the human brain in dealing with stress.”
In the past few centuries, in fact, it’s continued to serve this role for many groups facing some of the worst-possible human suffering under slavery and other forms of violent exploitation and oppression.
In many ways, this part of the human-cannabis relationship explains the plant’s history and status in the US, and in other Euro-colonized zones around the world, according to Aggarwal and his peers — in short, cannabis “helped with the social rejection of being a slave.”
By the early 1600s, the British empire and others in Europe were all on board for hemp as a valuable industrial commodity; in the coming centuries, they and their colonies (such as the US) would increasingly embrace cannabis medicine, too (leading to Eli Lilly’s early 20th-century cannabis tonics, for example, and the U.S. government’s late 20th-century patents on cannabis as an anti-oxidant and neuroprotectant — but hang onto that thought for now).
During the same timeframe, the European slave trade was booming, with hemp among the top crops that millions of trafficked and enslaved people of African, Central and South American, and North American Indigenous origin were being forced to grow. In the 1600s, Aggarwal said, cannabis as a cultural and spiritual drug probably first appeared in what is now the Americas among these enslaved populations.
“It’s interesting to see how it was brought [here] by slaves and indentured servants,” he noted. “It tells you an important aspect of how the plant has always been used: by downtrodden groups, as a way of dealing with difficult living conditions and psychological stress, as from being an indentured servant for your whole life.”
Imperial cultures took longer to get the memo on cannabis vs. hemp, however. As it was being imported to Europe through occupied India, Aggarwal said, “It was picked up by elite medical professionals and military figures in the history of medicine, which really brought attention to cannabis as a medicine in the West.”
By the 1920s, the socially and emotionally helpful plant had been included in any number of reputable Western pharmacopeia. Cannabis as a cultural substance also became an integral part of the US jazz scene, and was arriving state-side tucked into refrigerated barges, research suggests — hence the name “reefer,” Aggarwal said.
By that time, however, most US states and municipalities had also chosen to outlaw the plant despite its medical history here, and (as we know today) due to governments’ as well as private businesses’ racist, fearful, criminalizing stance toward its use in Black and Brown communities. In 1930, the US deemed the plant federally illegal.
In the era’s most oppressed communities, it continued to offer social relief, as well as a budding source of financial independence, which ties directly to today’s “underground” market.
In his article “Workers’ Weed,” researcher Nick Johnson noted: “During the first half of the twentieth century in the American West, Mexican and Mexican American farm workers grew and used Cannabis [to] help navigate the physical, mental, and economic struggles they faced as exploited itinerant laborers … [and] while the capitalist framework of the agricultural landscape kept workers pinned to the bottom of the socioeconomic ladder, the landscape itself provided spaces where they could use traditional knowledge of Cannabis to climb that ladder, albeit illegally.”
During the 1960s and ‘70s, Aggarwal said, cannabis once again emerged as a source of social, emotional, and even spiritual relief for a troubled generation — this time, including many white folks. “It was used by a large group of people who were looking violent death in the eye,” he said. “Communism vs. capitalism also created another existential crisis, and cannabis helped deal with that reality, and with the stress and fear of going to war.”
“It says a lot about our brains, and our evolutionary relationship to cannabis,” he said.
In the era of COVID-19-related shutdowns, layoffs, illness, and death, cannabis has again emerged as an important factor in Americans’ health and well-being, as well as their potential livelihoods and national economy going forward.
On one hand, most legal and medicinal cannabis dispensaries and delivery services in the US saw a spike in sales this spring as patients and adult users stocked up ahead of uncertain times, whether for medical, mental health, or relaxation purposes.
In a time when whole industries are being leveled (either without warning, or at long last) by the many-fold impacts of today’s pandemic, cannabis and hemp remain hugely promising as both in-demand products and significant sources of new employment.
On the other hand, many cannabis businesses are struggling to staff and finance their operations, often without ‘essential’ designation or equal access to relief funds.
Expensive, dangerous, and demonstrably racially biased arrests of Black and Brown people for minor cannabis offenses also continue, and farmers around the country are being forced to dump not only dairy and other perishable products, but also tons of sustainable, soil-improving hemp that could otherwise feed, clothe, warm, or house us.
Will evolutionary history shape our future choices?
In 2020, many Americans’ daily lives may not seem all that intertwined with nature — especially when it comes to the advanced medicines and supplements we put in and on our bodies, and in the context of ‘stay-at-home’ orders and growing cityscapes.
But warnings from a growing number of medical experts, environmental researchers, and social advocates seem to suggest that we are over-complicating important aspects of human life, in a way — as by putting extra stress on our bodies and minds, our environment and resources, and (among other top concerns of US residents) on how we practice and pay for human health.
As Aggarwal put it: “We’re in a situation where, due to the industrial revolution, the development of the chemical industry, the pharmaceutical industry in the West, and our desire to conquer nature rather than cohabitate with it — and to how we’ve developed medicine and health as a for-profit enterprise, and not made [legal] restrictions on the ability to privatize nature and natural plants — the result is that people have deemphasized a whole slew of plants and [other natural] substances that have value in terms of our neurological and psychological well-being.”
Lee echoed that point, and said that, as a society, we’ve turned away from the plants, fungi, and animal secretions that chemically beckoned our ancestors.
The same goes for “natural” or plant-based lifestyles in general, which could probably help most of us be healthier to begin with, and less in need of riskier, more expensive and/or cutting-edge solutions.
“We’re not just talking about cannabis, we’re talking about a whole tapestry of botanical opportunities … It has to do with how we interact with the environment: what we eat, how we eat,” Lee said.
For example, aside from natural medicines, our diets are often lacking in the kinds of plants and other items we’ve evolved to eat and metabolize into energy. “The way we metabolize plants vs. other things [commonly eaten today] is causing a lot of problems,” he said.
“Cannabis goes back a long way as a plant ally to humankind, along with many other allies, so it stands for that, too,” he continued. “What else are we pretending not to see in addition to how powerful and useful cannabis is? What are its natural handmaidens that are also being neglected?”
Despite the systemic hurdles that exist today, Lee said, people are continuously finding new ways to use the plant — whether as a form of food, medicine, cosmetics, astringent, industrial or artisanal fabric, building materials, fuel, or many other things — as well as ways to better understand and appreciate its psychoactive effects.
From sturdy hempcrete and luxury skin cream to sky-high shatter and medicinal drinks, these innovations are just some of the latest blooms in a powerful, long-standing relationship between cannabis and humans that has consistently benefited our species (if not all members equally).
And when faced with a particularly uncertain future, such as today, it seems more critical than ever for members and leaders of human society to recognize not only the mistakes we’ve made in the past but also who and what our strongest allies have been on this planet, and to act accordingly ASAP.