Scientists say two prehistoric foragers on the Indonesian island of Sulawesi sucked on psychoactive betel nuts thousands of years earlier than anyone previously believed humans used drugs, and the habit destroyed their teeth.
A research team led by Professor Adam Brumm of Griffith University examined the remains of two ancient individuals discovered on Sulawesi and found highly unusual dental-wear patterns, deep, rounded grooves worn into their teeth. The grooves, Brumm and his colleagues concluded, match the kind of damage caused by prolonged sucking on betel nuts, the hard seeds of the areca palm. The older of the two individuals lived between 25,000 and 16,000 years ago. The younger dates to roughly 7,600 to 6,300 years ago.
If the findings hold up, they push back the earliest known evidence of human drug use by more than 10,000 years. Until now, scholars widely believed that people first began using mind-altering substances during the Neolithic period, around 13,000 years ago, an era tied to the rise of farming. The Sulawesi discovery places the practice deep in the hunter-gatherer age, long before agriculture existed.
Betel nut is largely unknown in the West, but hundreds of millions of people across the Asia-Pacific region still chew it today. Brumm described the substance's global standing in blunt terms:
"Although poorly known in western societies, it is the world's fourth most widely used psychoactive substance, after alcohol, caffeine and nicotine."
The nut contains arecoline, a chemical compound that acts on the brain's neural receptors. To confirm that simply sucking on the nut, rather than grinding or chewing it, could deliver enough arecoline to affect the brain, Brumm's team ran laboratory experiments. They soaked whole betel nuts in artificial saliva and tested the resulting liquid against a panel of cloned human receptors grown in frog egg cells.
The results were clear.
"This showed that just sucking on intact betel nuts will release arecoline in sufficient amounts to have a physiological effect, altering brain function."
That finding matters because the ancient foragers on Sulawesi were not chewing the nuts the way modern users do. The dental-wear patterns suggest they held the hard seeds in their mouths and sucked on them over long periods, a more primitive method, but one the experiments proved was enough to get a psychoactive hit.
Why would prehistoric people develop a habit of sucking on hard, abrasive seeds for hours? Brumm's team believes the answer may be pain. The researchers suggest the foragers were trying to ease chronic toothaches, a common affliction in an era without dentistry.
But the cure created its own problem. Brumm described a vicious cycle:
"Over time, however, sucking these hard, abrasive seeds wore down the foragers' teeth so badly that in some cases the inner pulp chamber became completely exposed, this would have been extremely painful, caused difficulty eating, and greatly increased the rate of chronic tooth infection."
The exposed pulp chamber, the soft tissue at the center of a tooth, packed with nerves and blood vessels, would have caused excruciating pain. And that pain, in turn, gave the foragers even more reason to keep sucking on the nuts for relief.
"So while this habit may have been a remedy for toothache, years of prolonged nut-sucking eventually caused much worse dental health problems, creating a cycle of continued habitual use."
In short: the world's oldest known drug habit followed the same grim logic that addiction has followed ever since. A substance that dulled one kind of suffering produced another, and the user kept coming back.
The broader significance of the study lies in what it says about human nature and the timeline of drug use. Scholars had long linked the emergence of psychoactive substance use to the Neolithic revolution, the period roughly 13,000 years ago when humans began settling into agricultural communities, cultivating plants, and experimenting with fermentation and other processes that could produce intoxicating substances.
The Sulawesi evidence upends that framework. The older individual predates farming by at least several thousand years. These were mobile foragers, not settled farmers. They did not need agriculture to find a way to alter their brain chemistry. They just needed a nut and enough time to suck on it.
Brumm put the finding in historical context:
"Emerging by up to 25,000 years ago in Sulawesi, thus long preceding the onset of agriculture, betel nut-sucking may be the earliest evidence for drug use anywhere in the world."
He added that the discovery carries implications for understanding modern behavior as well:
"By identifying the ancient practice underlying betel-nut chewing as we know it, the study implies that some modern drug-taking behaviours are deeply rooted in forager traditions."
Several questions remain unanswered. The study does not specify whether the identification of betel nut use rests solely on the dental-wear analysis and the laboratory sucking experiments, or whether chemical residue from the nuts was also detected on the remains. The full list of co-authors beyond Brumm, the journal in which the study was published, and the specific excavation site on Sulawesi have not been detailed in available reporting. Nor is it stated whether both individuals are confirmed as modern humans.
What is confirmed is the pattern: two people, separated by thousands of years on the same island, both showing the same telltale grooves in their teeth. Both apparently locked into the same habit. Both paying the same price.
Human beings have been chasing a chemical shortcut to feeling better for at least 25,000 years. The technology changes. The impulse never does.
