Scientists from Griffith University (Australia) have presented data that could push the history of human psychoactive substance use thousands of years further into the past. The study, published in the scientific journal Science Advances, focuses on two ancient hunters whose remains were found on the Indonesian island of Sulawesi. According to Professor Adam Brumm, who led the work, the traces discovered may turn out to be the oldest evidence of psychoactive substance use in the world.

How the scientists reached their conclusion

The key material was the teeth of two hunter-gatherers. One of them lived approximately 25,000–16,000 years ago, the other — 7,600–6,300 years ago. On the teeth of both, specialists noticed unusual signs of wear in the form of characteristic round depressions. Using specialized analyses, the researchers established that such marks arise as a result of prolonged chewing of the betel nut. To test the hypothesis, the team conducted an experiment, soaking the nuts in artificial saliva: it turned out that even simply chewing a whole seed was enough to release a sufficient amount of psychoactive substances to affect brain function.

What is the betel nut and how is it consumed

The betel nut is the seed of the areca palm. When consumed, it produces a mild elevated mood, a state of euphoria, and increased sensitivity in humans. "Although this substance is little known in Western society, it is the fourth most popular psychoactive substance in the world after alcohol, caffeine, and nicotine," Brumm noted. Today, betel seeds are chewed mixed with slaked lime and other ingredients; this practice is widely spread across South and Southeast Asia and, by estimates, affects about a tenth of the world's population.

Revising previous views

It was previously believed that the use of psychoactive substances began only after the emergence of agriculture — around 13,000 years ago, together with the invention of alcoholic beverages. The new study calls this theory into question: the roots of the most common psychoactive substances, Brumm says, reach back to a much more ancient past. "This study means that some forms of modern addictive behavior originate in the traditions of ancient hunters," the scientist added. Thus, the history of the 'chemical' influence on consciousness may turn out to be significantly older than previously assumed.