Prehistoric Cave Remains in Indonesia Reveal the Earliest Known Human Drug Use

Prehistoric human remains uncovered on the Indonesian island of Sulawesi indicate that humans were consuming psychoactive substances thousands of years earlier than previously documented. The discovery pushes the origins of mind-altering substance use far back into the deep hunter-gatherer past, long before the advent of agriculture.

The substance identified through the archaeological material is the betel nut, which is the fruit seed of the areca palm tree. In modern times, the betel nut ranks as the world's fourth most commonly consumed psychoactive substance, trailing only caffeine, alcohol, and nicotine in its global reach and daily usage.

Today, approximately 10 percent of the global population, concentrated primarily across regions of Asia and the Pacific, engages in the traditional practice of chewing betel nut. In modern settings, users typically consume it in the form of a prepared package known as a quid, which combines the processed seed with slaked lime.

The inclusion of slaked lime, chemically identified as calcium hydroxide, is critical to the contemporary chewing process. The substance initiates an essential chemical reaction that dramatically accelerates the body's absorption of the active compound arecoline into the bloodstream, producing sensations of mild euphoria along with heightened mental alertness.

Until now, the archaeological community held a substantially different view regarding the origins of such chemical usage. Researchers widely maintained that structured traditions of psychoactive drug consumption did not emerge until approximately 13,000 years ago, coinciding with the transition of nomadic hunter-gatherer groups into settled farming societies.

This broader transition, known as the Neolithic Revolution, has historically been associated with the dawn of human intoxicants, such as early agriculturalists in modern-day Israel brewing beer from barley. Earlier scientific findings had indicated that betel nut consumption in Southeast Asia began approximately 4,000 years ago.

However, a newly published study in the journal Science Advances demonstrates that preagricultural foragers in Sulawesi were already sucking on whole betel nuts between 25,000 and 16,000 years ago. This discovery suggests that the customary use of the areca palm seed predates earlier records by tens of thousands of years.

The initial physical evidence came from archaeological work conducted in 2017 at Leang Bulu Bettue, a limestone cave located within the mountainous Maros-Pangkep karst landscape of South Sulawesi. The excavation yielded an upper jawbone fragment belonging to an adult forager who inhabited the area during the late Pleistocene epoch.

Finding well-preserved skeletal remains from this era represents an uncommon scientific feat due to the severe environmental conditions of the region. Tropical climates like that of Sulawesi typically accelerate the decomposition and degradation of ancient organic matter, making the recovered jaw fragment a rare physical record.

Upon closer examination of the three surviving teeth embedded in the jawbone, researchers noticed peculiar structural wear. Two of the prehistoric teeth exhibited deep, smoothed, and rounded grooves, which the research team identified as physical wear patterns caused by repeatedly holding and sucking on whole betel nuts over extended periods.

Corroborating evidence emerged from a second archaeological site located roughly 20.5 miles (33 kilometers) away at another cave known as Leang Cappolombo. Excavations carried out there in 2017 brought to light the remains of another adult forager whose teeth exhibited the exact same distinctive grooving patterns.

Although this second specimen dated to a more recent timeframe, between 7,600 and 6,300 years ago, the identical dental wear confirmed that the practice had persisted as a continuous cultural behavior over many millennia. The research team was able to analyze these specific teeth starting three years ago.

According to lead study author Adam Brumm, an archaeology professor at Griffith University's Australian Research Centre for Human Evolution, prehistoric hunter-gatherers were likely using whole betel nuts for their properties as a primitive pain reliever. While lacking the added chemical potency provided by slaked lime in modern quids, the raw seeds still provided active physiological effects.

However, this medicinal benefit came with severe biological drawbacks for the ancient users. Professor Brumm noted that while the seeds offered temporary relief from physical discomfort, their neuroactive properties encouraged sustained dependence, while the physical act of sucking the hard seeds caused severe dental damage that likely generated further oral pain.

This dynamic effectively trapped ancient foraging communities in a destructive behavioral loop, where the remedy for oral discomfort exacerbated the underlying physical trauma. The findings illustrate that long before humanity established sedentary farming communities, early hunter-gatherers were already actively managing physical distress through plant-derived neuroactive compounds.