Prehistoric Remains Reveal Earliest Known Evidence of Human Drug Use

Archaeological discoveries on the Indonesian island of Sulawesi have pushed back the known timeline of human psychoactive drug consumption by tens of thousands of years. Distinctive wear patterns identified on the teeth of ancient hunter-gatherers indicate that early humans were routinely consuming mind-altering plant substances far earlier than previously documented by science.

The substance at the center of the discovery is the betel nut, a seed harvested from the areca palm tree. In the contemporary world, the betel nut ranks as the fourth most prevalent psychoactive substance, trailing only caffeine, alcohol, and nicotine in global popularity.

Modern consumption of the plant remains widespread, with approximately one in every ten individuals across the globe regularly engaging in the custom. This practice is particularly prominent across communities throughout Asia and the Pacific region, where users chew a prepared mixture known as a quid.

In its modern form, the quid consists of processed betel nut combined with slaked lime, a substance chemically identified as calcium hydroxide. Adding slaked lime is critical to the experience, as it prompts a chemical reaction that accelerates how quickly the psychoactive chemical arecoline enters the user's bloodstream. Once absorbed, the compound induces a state of heightened alertness paired with feelings of mild euphoria.

For many decades, the standard scientific timeline asserted that widespread, habitual drug consumption did not emerge until approximately 13,000 years ago. Researchers widely associated the emergence of mind-altering substances with the Neolithic Revolution, a transformative era when nomadic hunter-gatherer populations began settling into permanent agricultural villages and domesticating crops.

Historical records from that agricultural era indicate that early farming communities in the territory of modern-day Israel developed methods to brew beer utilizing barley. In Southeast Asia, earlier archaeological excavations had previously traced the tradition of chewing betel nut back roughly 4,000 years.

However, the new research shows that early foraging groups were using whole betel nuts between 25,000 and 16,000 years ago. This discovery suggests that long before the dawn of systematic agriculture, prehistoric people were already utilizing the natural stimulants found in their local ecosystems, establishing an ancient foundation for the betel nut traditions observed today.

According to the research team, ancient foragers did not prepare the seed with lime but instead sucked on whole betel nuts. While this primitive method yielded a less intense psychoactive effect than modern quids, the nuts still acted as an effective painkiller for prehistoric individuals dealing with physical discomfort.

This medicinal use, however, appears to have triggered a self-perpetuating cycle of dependence and dental deterioration. Sucking the hard seeds provided temporary relief from physical pain, but the repetitive mechanical action ground down the foragers' teeth, creating deeper dental damage that ultimately provoked greater pain and encouraged continuous use of the plant.

Adam Brumm, a professor of archaeology at Griffith University's Australian Research Centre for Human Evolution and the lead author of the study published in the journal Science Advances, explained that these findings alter our understanding of ancient humanity. He noted that early foraging populations were not merely utilizing psychoactive plants millennia earlier than once thought, but were also developing chemical dependencies and experiencing the detrimental physical side effects associated with chronic use.

The physical evidence underpinning these conclusions was first uncovered in 2017 during excavations at Leang Bulu Bettue. This limestone cavern is situated within the rugged Maros-Pangkep karst region of South Sulawesi.

Inside the cave, archaeologists recovered a fragment of an upper jawbone belonging to an adult preagricultural forager who occupied the shelter between 25,000 and 16,000 years ago. The fossilized fragment retained three preserved teeth, two of which displayed unusual, deeply worn, rounded grooves indicative of repetitive friction.

Skeletal discoveries of this vintage are remarkably uncommon in equatorial territories. The hot, humid climate typical of tropical islands like Sulawesi tends to accelerate decomposition, making the survival of Pleistocene-era human remains a rare occurrence for archaeologists.

The findings at Leang Bulu Bettue are corroborated by separate remains excavated approximately 20.5 miles, or 33 kilometers, away at another cave site called Leang Cappolombo. At that location, researchers in 2017 unearthed the skeletal remains of a second adult forager, dated to between 7,600 and 6,300 years ago.

When Brumm's research team was able to examine the Leang Cappolombo fossils three years ago, they observed identical rounded grooves worn into the tooth enamel. The presence of identical dental wear across two separate sites spanning thousands of years confirms that sucking whole betel nuts was an established cultural behavior in prehistoric Sulawesi.

Collectively, these fossil records redefine the history of human substance use, proving that hunter-gatherers had integrated psychoactive plants into their daily survival strategies tens of thousands of years before the advent of farming.