Ancient human teeth unearthed on the Indonesian island of Sulawesi have pushed back the known history of psychoactive drug use by tens of thousands of years, with new research suggesting hunter-gatherers were habitually sucking betel nuts as far back as 25,000 years ago — long before the dawn of agriculture or any previously recorded tradition of mind-altering substance use.
The findings, from a study led by Professor Adam Brumm of Griffith University, are based on the examination of teeth recovered from two ancient skeletons found on Sulawesi. One individual lived between 16,000 and 25,000 years ago; the other between 6,300 and 7,600 years ago. Both sets of teeth displayed distinctive deep, rounded grooves that researchers determined were caused by the repeated sucking of betel nuts — a behaviour not previously documented in the archaeological record.
What the Ancient Teeth Reveal About Early Drug Use
The betel, or areca nut, is a palm seed native to Southeast Asia and ranks as the fourth most commonly used psychoactive substance in the world, behind alcohol, caffeine and nicotine. Today it is typically mixed with slaked lime powder and chewed, a combination that amplifies its psychoactive properties and produces a powerful stimulant effect capable of inducing mild euphoria and heightened alertness.
However, the ancient hunter-gatherers in this study pre-dated that practice. Researchers believe these individuals were simply sucking the raw nut — most likely for pain relief rather than to get high.
"We think this was a longstanding cultural tradition of drug use that predated the invention of betel nut chewing as we know it today," Professor Brumm said. "We think this is how humans discovered the mind-altering properties of this particular type of drug."
While Brumm acknowledged the possibility that users were receiving some psychoactive effect, he was careful to draw a distinction: "We can't exclude that they were getting a psychoactive hit but… we don't think they were getting high on sucking betel nut."
The pattern of dental wear observed in the skeletons points to a deeply habitual behaviour. Continuous sucking of the nut eroded tooth enamel over time, leading to cavities and significant pain — which, in turn, likely drove further use of the nut to manage that pain. It is a cycle researchers describe as fundamentally addictive in nature, making these findings not only the earliest evidence of deliberate psychoactive plant consumption, but also the earliest known evidence of habitual drug use.
Rewriting the Timeline of Human Drug Use
Until now, the prevailing view among scientists was that organised traditions of psychoactive substance use emerged only after humans began farming. The earliest known example had been fermented barley beer, traced back approximately 13,000 years to the region now known as Israel — itself a product of the Neolithic agricultural revolution.
The Sulawesi findings shatter that timeline. They indicate that habitual drug use — along with its associated health consequences — was already a feature of human behaviour among hunter-gatherer communities tens of thousands of years before agriculture existed.
Over generations, it is thought, people in the region discovered they could intensify the nut's effects by combining it with slaked lime, eventually developing the chewing tradition that remains widespread across parts of Asia and the Pacific today. That evolutionary leap in drug preparation represents one of humanity's earliest known experiments in pharmacology.
The Significance of the Discovery
The study raises profound questions about the deep roots of human behaviour around psychoactive substances. The fact that these hunter-gatherers appear to have fallen into a cycle of use driven partly by pain and partly by the nut's stimulating properties suggests that the complex relationship between humans and mind-altering substances is far more ancient than modern science had previously appreciated.
Professor Brumm's research underscores that the health costs associated with habitual drug use are not a product of modern life or even of settled agricultural society — they appear to be woven into the human story at a much earlier point.
For context, the betel nut's enduring global presence — it remains one of the most widely consumed psychoactive substances on earth — takes on new meaning in light of these findings. What was once seen as a cultural tradition with relatively recent origins may in fact represent one of the longest-running examples of habitual human drug use ever documented.
The Griffith University study adds to a growing body of work that is fundamentally challenging long-held assumptions about ancient human behaviour, health, and the choices our ancestors made in the absence of modern medicine. As excavations in the region continue, researchers say further discoveries may yet extend the timeline even further back into prehistory.
