Sulawesi Teeth Suggest Betel Nut Use Began 25,000 Years Ago

Ancient teeth from two hunter-foragers on Indonesia’s Sulawesi island provide evidence that people were regularly using psychoactive betel nuts as far back as 25,000 years ago. The study combines distinctive tooth wear, chemical residues and laboratory tests, making this a strong candidate for the earliest known evidence of habitual psychoactive substance use. 12

What the two individuals reveal

The remains belong to people who lived in different periods. One individual, described as a man, died roughly 25,000 to 16,000 years ago; the other lived about 7,600 to 6,300 years ago. Both were estimated to have been 40 to 50 years old at death. 8

Their teeth had unusually deep, rounded grooves and severe wear. Researchers interpret those marks as the result of repeatedly holding hard, whole betel nuts in the mouth and sucking them for long periods, rather than chewing a prepared betel quid. 12

Chemical analysis found arecoline in the dental tissue. Arecoline is the principal psychoactive alkaloid in the seed of the areca palm, commonly called betel nut. Together with the matching wear pattern, the residue supports repeated ingestion rather than a one-time exposure. 14

Why whole-nut sucking could have had an effect

Modern betel preparations often include slaked lime, or calcium hydroxide, which speeds the absorption of arecoline. The ancient evidence did not indicate use of slaked lime, suggesting a simpler and older practice: sucking whole nuts. 15

That does not mean the practice was non-psychoactive. In experiments reported by the research team, intact betel nuts exposed to artificial saliva released arecoline. The released compound activated relevant human receptors in a laboratory system, indicating that prolonged sucking could deliver a physiologically active dose even without lime. 14

The likely effect would have differed from that of a modern lime-treated quid: lime made absorption faster and stronger, while whole-nut sucking appears to have released the compound more gradually. 15

A possible remedy with damaging consequences

The researchers suggest that betel nuts may have been used in part to ease toothache. That idea is plausible because arecoline has analgesic properties and the individuals had heavily damaged teeth, but it cannot establish what either person intended when using the nuts. 18

There is a clear irony in the dental record. The abrasive nuts appear to have contributed to extreme wear, periodontal disease and, in some teeth, exposure of the pulp chamber. A substance that may have offered relief could therefore also have intensified the oral damage associated with repeated use. 1

The broader implication is cautious but important: Ice Age foragers may have recognized that a natural substance could alter sensation and ease pain. The evidence supports habitual betel-nut use and is consistent with pain relief; it does not directly prove that the nuts were used to treat infection. 1

Why the discovery changes the drug-use timeline

Before this finding, fermented barley beer from about 13,000 years ago was often cited as the earliest evidence for psychoactive substance use. If the Sulawesi interpretation holds, habitual use extends roughly 12,000 years further back, to Ice Age hunter-foragers rather than agricultural communities. 1

It also changes the proposed history of betel use. Earlier models placed its beginnings in the Neolithic or Bronze Age, around 3,500 years ago. The Sulawesi evidence suggests the practice may have begun up to 25,000 years ago, with today’s lime-enhanced chewing traditions representing a later technological development of a much older habit. 1

What is firmly supported—and what remains open

The most compelling result is the convergence of three lines of evidence: unusual dental grooves, arecoline in ancient teeth, and experiments showing saliva can release arecoline from intact nuts. 14

Researchers can reasonably infer repeated whole-nut sucking and psychoactive exposure. Questions about the exact intensity of the effect, the social meaning of the practice and whether pain relief was the primary motivation remain interpretations rather than direct observations. 1