Long before ayahuasca became popular among Silicon Valley seekers, it was the domain of specialized healers and spiritual leaders. Archaeologists have long known that ancient peoples throughout the Americas consumed various plant-based drugs to heal, find meaning, and connect to a spiritual world, but research published Monday in PNAS suggests that they were used even more widely than scientists suspected.
In the paper, an international team of archaeologists identified traces of five different psychoactive chemicals in a bundle of belongings dating back to about 1,000 years ago. The objects, found in Cueva del Chileno, a rock shelter in the Andes in present-day Bolivia, include animal-skin pouches and a headband, as well as spatulas, two trays, and an intricately carved tube — tools that were most likely used for sniffing a plant-based psychedelic drug.
Using radiocarbon dating, the team showed that the leather bag containing the objects dates back to somewhere between 905 and 1170 CE. And using liquid chromatography tandem mass spectrometry, they found that the kit contained traces of cocaine, dimethyltryptamine (DMT), harmine, bufotenine, and benzoylecgonine — psychoactive chemicals that are all found in various plants native to South America.
The researchers, a team from Pennsylvania State University, the University of Otago in New Zealand, the Higher University of San Andrés in Bolivia, and the University of California, Berkeley, write that these findings demonstrate just how extensive the botanical knowledge of the people in this region was.
“Our results indicate that this is the largest number of psychoactive compounds found in association with a single archaeological artifact from South America,” they write. “The chemical residues of at least five compounds that are known to have psychotropic effects on humans, present in the fox-snout pouch, imply that multiple plants were used to induce extraordinary states of consciousness, potentially within a range of ritual and healing contexts.”
Perhaps most significantly, the plants that produce the chemicals analyzed at the site do not grow in the place where they were found. The archaeologists note that while the site is located in the mountains, at an elevation of almost 13,000 feet above sea level, most of these plants grow in the lowland forests of the Amazon.
“Because these plants are foreign to the Lípez highlands, it remains to be established whether they were acquired through trading networks or directly by the shamans themselves,” they write.
Here’s a breakdown of the chemicals and plants found at the site:
- Cocaine: Cocaine comes from the coca plant (Erythroxylum coca), but its presence at this archaeological site doesn’t necessarily indicate that people were refining cocaine into the white powder. The leaves were commonly brewed in a tea or chewed for stimulant effects and to help with altitude sickness.
- Bufotenine: Bufotenine (5-HO-DMT) is found in the seeds of the trees Anadenanthera peregrina and Anadenanthera colubrina. These seeds have a long history of use as a psychedelic snuff — which suggests that the tools in the kit were intended for crushing and sniffing these seeds. Both A. peregrina and A. colubrina grow throughout much of South America, but not above about 8,000 feet in elevation.
- Dimethyltryptamine: This molecule, best known as DMT, is one of the main components of ayahuasca, a liquid brew consumed for its ability to manifest vivid spiritual experiences. In the Amazon, DMT is most commonly found in the Psychotria viridis plant. This archaeological evidence suggests that whoever lived at this site was using ayahuasca, which would provide some of the earliest evidence of the practice in South America. The researchers are careful to note, however, that DMT is also found in trace quantities in the seeds of A. peregrina and A. colubrina, meaning that the ayahuasca hypothesis is not certain.
- Harmine: This chemical is found in Banisteriopsis caapi, an Amazon native that provides the other half of ayahuasca, along with P. viridis. Again, though, shamans in South America were already using harmine-containing plants to alter the experience of the seed snuff, so evidence of harmine is not necessarily evidence of ayhuasca.
- Benzoylecgonine: This chemical is a metabolite of cocaine, and it’s also present in the coca plant.
The varied origins of the plants suggest that South Americans had such a rigorous knowledge of plants 1,000 years ago, that there was already a rich international trade in these psychoactive substances.
The mass spectrometry also hinted at the presence of psilocin, one of the active chemicals in psychedelic mushrooms, but this particular result was inconclusive.
One thing the archaeologists did not find was human remains, which they suspect must have been removed long ago. So while they can’t test any human remains to determine whether the people who inhabited this shelter were using all these drugs at the same time, “the substantial evidence of the presence of hallucinogenic plants is compelling.”
In short, this site suggests that as long as 1,000 years ago, people who lived in this region were using multiple substances together. While some parts of this study need further evaluation, it shows conclusive evidence of three different hallucinogenic plants, which, the researchers write, is “the highest number of such specimens recovered from a single South American artifact.”
Abstract: Over several millennia, various native plant species in South America have been used for their healing and psychoactive properties. Chemical analysis of archaeological artifacts provides an opportunity to study the use of psychoactive plants in the past and to better understand ancient botanical knowledge systems. Liquid chromatography tandem mass spectrometry (LC-MS/MS) was used to analyze organic residues from a ritual bundle, radiocarbon dated to approximately 1,000 C.E., recovered from archaeological excavations in a rock shelter located in the Lípez Altiplano of southwestern Bolivia. The site is located at an elevation of ∼3,900 m above sea level and contains evidence of intermittent human occupations during the last 4,000 years. Chemical traces of bufotenine, dimethyltryptamine, harmine, and cocaine, including its degradation product benzoylecgonine, were identified, suggesting that at least three plants containing these compounds were part of the shamanic paraphernalia dating back 1,000 years ago, the largest number of compounds recovered from a single artifact from this area of the world, to date. This is also a documented case of a ritual bundle containing both harmine and dimethyltryptamine, the two primary ingredients of ayahuasca. The presence of multiple plants that come from disparate and distant ecological areas in South America suggests that hallucinogenic plants moved across significant distances and that an intricate botanical knowledge was intrinsic to pre-Columbian ritual practices.