Prehistoric Cave Discoveries Reveal Drug Use Dates Back 25,000 Years

Prehistoric human remains excavated on the Indonesian island of Sulawesi have pushed back the timeline of human drug use by thousands of years. According to a newly published study, early hunter-gatherers were consuming mind-altering substances tens of thousands of years earlier than archaeologists previously recognized.

The findings center on the use of the betel nut, which is the fruit seed produced by the areca palm tree. In modern times, the betel nut ranks as the fourth most popular psychoactive drug across the globe, trailing only caffeine, alcohol, and nicotine in its worldwide consumption.

Today, roughly one out of every ten people across the globe consumes the substance, with usage heavily concentrated among communities in Asia and the Pacific. Contemporary users traditionally chew the seed in the form of a prepared package known as a quid, which combines the processed nut with slaked lime.

The inclusion of slaked lime, chemically known as calcium hydroxide, is crucial to the modern chewing experience. The compound instigates a chemical reaction that accelerates the body's absorption of arecoline, the primary psychoactive alkaloid in the seed, directly into the bloodstream to deliver a state of heightened alertness and mild euphoria.

However, the newly analyzed prehistoric evidence demonstrates that early humans were engaging with the plant in a different manner long before the advent of the slaked-lime quid mixture. Ancient foragers appear to have sucked on whole betel nuts, engaging in a primitive form of drug use that predates modern preparations.

This revelation challenges long-held scientific assumptions regarding when humans first turned to stimulants and intoxicants. For decades, the archaeological consensus held that systematic drug habits first developed roughly 13,000 years ago, coinciding with the transition of nomadic hunter-gatherers into settled agricultural societies.

During that era, known as the Neolithic Revolution, settled farming enabled new forms of plant processing, such as the early brewing of barley beer by farming communities in what is now modern-day Israel. Prior to the recent discovery, the earliest confirmed physical evidence of betel nut chewing in Southeast Asia extended back approximately 4,000 years.

The breakthrough pushed that boundary back by tens of millennia following archaeological excavations in South Sulawesi’s rugged Maros-Pangkep karst region. In 2017, researchers working at the Leang Bulu Bettue limestone cave unearthed an ancient fragment of a human upper jawbone.

Dating revealed that the jawbone belonged to an adult preagricultural forager who inhabited the cave system between 25,000 and 16,000 years ago. An examination of the specimen showed three intact teeth, two of which displayed distinct, deep, rounded grooves caused by repeatedly holding and sucking on the plant material.

Discovering such ancient human fossils is exceedingly uncommon in tropical regions like Sulawesi. The intense heat and humidity characteristic of the local environment typically cause organic matter to deteriorate rapidly, making the preservation of the cave jawbone an extraordinary occurrence.

The validity of the dental evidence was further reinforced by a separate archaeological discovery made in 2017 at another cave site named Leang Cappolombo, located roughly 20.5 miles, or 33 kilometers, away from the initial site. That team uncovered skeletal remains belonging to a second adult forager who lived between 7,600 and 6,300 years ago.

Although the second set of remains was not analyzed by the study's lead researchers until three years ago, the teeth exhibited the exact same distinctive wear patterns and grooves found on the older specimen from Leang Bulu Bettue. This identical wear pattern indicates that the practice persisted in the region across thousands of years.

Researchers determined that while whole betel nuts lack the heightened potency achieved when mixing them with slaked lime, they still provided therapeutic properties. Prehistoric foragers likely relied on the seeds as an accessible pain reliever to cope with the physical hardships of their daily survival.

However, relying on the nuts for relief appears to have trapped these early populations in a damaging pattern. The continuous sucking and chewing eroded their dental health over time, causing severe wear to their teeth and ultimately generating greater physical pain that prompted continued consumption of the substance.

The findings were detailed in a study published in the journal Science Advances, led by Adam Brumm, an archaeology professor at Griffith University’s Australian Research Centre for Human Evolution. Brumm emphasized that early foraging groups were not only experimenting with neuroactive plants far earlier than anticipated, but they were also experiencing long-term negative consequences and developing dependency.

The discovery fundamentally alters the historical narrative surrounding psychoactive plant usage, showing that drug dependency and self-medication are not mere byproducts of farming and civilization, but deeply entrenched human behaviors stretching back to the Ice Age.