Level 1 — Absolute Beginner
Scientists studied old teeth from two ancient people. These people lived on an island called Sulawesi. Sulawesi is part of Indonesia today. One set of teeth is very old. It may be 25,000 years old.
The teeth had strange, deep marks on them. Scientists think the marks came from betel nuts. Betel nuts are also called areca nuts. The ancient people held whole betel nuts in their mouths for a long time.
Betel nuts have a chemical inside them called arecoline. This chemical can change how the brain feels. Scientists found small amounts of arecoline in the old teeth. Tests showed that whole betel nuts release this chemical slowly.
Maybe people used betel nuts to help with tooth pain. But using them for a long time hurt their teeth badly. This may be the oldest known example of people using a drug again and again. Many people in Asia and the Pacific still use betel nuts today.
- ancient
- very old, from a long time ago
- teeth
- the hard white parts in your mouth used for biting and chewing
- island
- a piece of land with water all around it
- scientists
- people who study the world to learn new facts
- chemical
- a substance that can change or affect the body
- drug
- a substance that changes how the body or mind feels
- habit
- something a person does again and again
- pain
- the feeling of hurting
Level 2 — Elementary
A new study, published in the journal Science Advances on September 9, 2026, examined the teeth of two prehistoric hunter-gatherers. These people lived on the island of Sulawesi, in what is now Indonesia, thousands of years apart. The older set of teeth was dated to as much as 25,000 years ago.
Both sets of teeth showed the same unusual, deep grooves. Researchers believe these grooves came from long-term sucking on whole betel nuts, also known as areca nuts. This is different from the more common modern method of chewing betel nuts together with lime.
The scientists also discovered traces of arecoline, a mind-altering chemical compound found in betel nuts, preserved inside the ancient teeth. Laboratory tests confirmed that whole, uncracked betel nuts slowly release arecoline when they stay in contact with saliva for a long time. This supports the idea that these ancient people kept the nuts in their mouths for extended periods.
Researchers think the habit may have started as a way to ease tooth pain, but over time it caused serious damage to the users' teeth. This finding is considered the earliest known evidence of habitual drug use anywhere in the world. Betel nut remains one of the most widely used mind-altering substances today, especially in parts of Asia and the Pacific.
- prehistoric
- from a time before written history existed
- hunter-gatherer
- a person who lives by hunting animals and collecting wild plants for food
- groove
- a long, narrow cut or mark in a surface
- mind-altering
- able to change the way a person thinks or feels
- compound
- a substance made of two or more parts joined together
- preserved
- kept safe from damage or decay over time
- saliva
- the liquid produced in the mouth
- habitual
- done regularly and repeatedly, as a habit
Level 3 — Intermediate
A study published in the journal Science Advances on September 9, 2026, has pushed back the timeline for humanity's earliest known drug habit by examining the teeth of two prehistoric hunter-gatherers from the island of Sulawesi, in present-day Indonesia. Although the two individuals lived thousands of years apart, the older set of teeth was dated to as much as 25,000 years ago, making it one of the most ancient pieces of physical evidence for intentional substance use ever recovered.
What caught researchers' attention was that both sets of teeth displayed the same distinctive pattern of deep grooves, a wear pattern they attribute to prolonged, repeated sucking on whole, unbroken betel nuts, also called areca nuts. This contrasts with the more familiar modern practice, still widespread across parts of Asia and the Pacific, of chewing crushed betel nut together with lime.
To support their interpretation, the team identified traces of arecoline, the psychoactive compound responsible for the nut's stimulant and mood-altering effects, preserved within the ancient dental tissue. Subsequent laboratory experiments demonstrated that whole, uncracked betel nuts release arecoline gradually when held in extended contact with saliva, a finding consistent with the idea that these individuals deliberately kept the nuts in their mouths for long stretches of time rather than chewing and discarding them quickly.
The researchers propose that the practice may have originated as a form of self-treatment for tooth pain, only to become a source of further, more severe dental damage as its use continued over years or decades. Considered together, the findings represent the earliest documented case of habitual drug use anywhere in the archaeological record, underscoring how deeply rooted humanity's relationship with mind-altering substances truly is.
- prehistoric
- belonging to the time before written records began
- distinctive
- clearly different from others, easy to recognize
- prolonged
- continuing for a long time
- psychoactive
- affecting the mind or mental state
- stimulant
- a substance that increases activity in the body or mind
- dental
- relating to teeth
- self-treatment
- treating one's own problem without a doctor
- archaeological
- relating to the study of ancient human life through physical remains
Level 4 — Advanced
A study published in the journal Science Advances on September 9, 2026, has extended the documented history of habitual psychoactive substance use by several millennia, drawing on dental analysis of two prehistoric hunter-gatherers who inhabited the island of Sulawesi, in present-day Indonesia, at intervals separated by thousands of years. The elder of the two specimens has been dated to as much as 25,000 years before present, positioning it among the oldest physical evidence yet uncovered for deliberate, sustained substance consumption in the human archaeological record.
Both individuals' teeth exhibited an identical and unusual pattern of deep grooves, a form of dental wear that the research team attributes not to the crushing and chewing typical of later betel nut consumption, but to prolonged, repeated sucking on whole, uncracked areca nuts. This distinction matters: the widespread contemporary practice across much of Asia and the Pacific typically involves chewing the nut in combination with lime, a method that leaves a markedly different signature on tooth structure than the one observed here.
Corroborating this interpretation, the researchers detected residual traces of arecoline, the areca nut's principal psychoactive alkaloid, preserved within the ancient dental material itself. Laboratory testing further established that intact, uncracked betel nuts release arecoline gradually under conditions of extended exposure to saliva, a mechanism entirely consistent with the notion that these individuals held the nuts in their mouths over prolonged periods rather than processing and discarding them rapidly.
The authors propose that the behavior may have arisen initially as an improvised remedy for dental pain, a plausible motivation that nonetheless failed to offset the cumulative, and ultimately severe, damage such prolonged use inflicted on the teeth themselves. Taken together, the findings constitute, by current evidence, the earliest documented instance of habitual drug use anywhere in the world, a reminder that betel nut, still among the most widely consumed psychoactive substances globally, particularly across South and Southeast Asia and the Pacific, sits at the head of an extraordinarily long human lineage of intentional substance use.
- millennia
- periods of a thousand years each
- dental
- relating to teeth
- alkaloid
- a natural chemical compound, often from plants, that can affect the nervous system
- corroborating
- confirming or supporting a claim with additional evidence
- residual
- remaining in small amounts after most of something has gone
- cumulative
- increasing gradually as more is added over time
- lineage
- a line of descent or continuous development over time
- psychoactive
- capable of affecting the mind, mood, or behavior
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