Archaeological evidence shows that South Americans were chewing coca leaves at least 8,000 years ago, an international team of researchers has discovered.
The researchers, who were led by Dr. Tom Dillehay of the Vanderbilt University Department of Anthropology, discovered and dated coca leaves beneath house floors in the Nanchoc Valley of Peru.
Dillehay and colleague describe their findings in a paper, which appears in the latest edition of Antiquity, a quarterly journal of archaeology founded in 1927.
Furthermore, they also discovered fragments of calcite, which according to the researchers "is used by chewers to bring out the alkaloids from the leaves."
"Excavation and chemical analysis at a group of neighboring sites suggests that specialists were beginning to extract and supply lime or calcite, and by association coca, as a community activity at about the same time as systematic farming was taking off in the region," they added.
According to BBC News Science and Technology Reporter Jason Palmer, the discovery shows that people were using coca at least 3,000 years earlier than first believed. The alkaloids contained in coca leaves can serve as mild stimulants, can reduce hunger, can help the digestive process, and can help individuals overcome the effects of high-altitude, low-oxygen environments, he added.
"We found it not so much in a household context, as if it was something that was heavily used by a lot of people, but rather... restricted to certain households of individuals and produced in a sort of public context - not individualized," Dillehay told Palmer.
"The evidence we have suggests that unlike in Western societies--where if you've got the economic means you can have access to medicinal plants--that seems not to be the case back then," he added.
Palmer notes that the discovery could also have an effect on modern-day policy making, as the international community is attempting to curb the production of coca in the Andes due to its association with cocaine.
Dillehay told Palmer that people are too focused on the cocaine-related aspects of the plant, and they fail to see that the use of the coca plan is "a deeply-rooted economic, social and even religious tradition in the Andes."