Using evidence from these artifacts, the researchers traced the rapid spread of cacao through trade routes after its initial domestication more than five millennia ago in Ecuador.
They showed cacao’s dispersal to South America’s northwestern Pacific coast and later into Central America until it eventually reached Mexico 1,500 years later.
A tropical evergreen tree called Theobroma cacao bears large, oval pods containing the bean-like cacao seeds that today are roasted and turned into cocoa and multitudes of chocolate confections.
In these ancient times, cacao was consumed as a beverage or an ingredient with other foods.
The researchers tested more than 300 pre-Columbian ceramics spanning nearly 6,000 years for traces of cacao DNA and three chemical compounds related to it, including caffeine.
They discovered cacao evidence on about 30% of them. The findings indicate cacao products were used more widely among these ancient cultures than previously known.
The ceramics themselves offered an artistic glimpse at the cultures, some displaying wondrous anthropomorphic designs.
A study published in 2018 revealed the domestication and use of cacao beginning about 5,300 years ago in Ecuador, based on evidence from ceramics at the Santa Ana-La Florida archeological site.
The significant genetic mixing that was observed testifies to numerous interactions that could have happened between peoples from Amazonia and the Pacific coast,” Lanaud added.
Cacao’s dispersal from Ecuador to Mesoamerica may have occurred through vast and interconnected political-economic networks, according to the researchers.
“First of all, we can firmly state that the origin of cacao and its domestication was the Upper Amazon and not in the tropics of Mesoamerica – Mexico and Central America.
The process of dispersal was rather quick and involved the close and long-distance interaction of the Amerindian people,” said archaeologist and study co-author Francisco Valdez of the PALOC unit of France’s IRD research institution and Museum National d’Histoire Naturelle in Paris.
“Maritime contacts must have been involved as well as the inland contacts. Previously, the common (belief) was that cacao was domesticated in the Mesoamerican lowlands and that it was dispersed from there to the south,” Valdez said.
The study provides insight into the earliest trade in what is now one of the world’s most important cash crops. Today’s sugary chocolate confections differ greatly from cacao’s early uses.
Before Europeans reached the Americas five centuries ago, cultures like the Aztecs and Maya prepared it as a drink, mixed with various spices or other ingredients.
“Cacao as a plant is an energy-source food, as well as a medicinal product,” Valdez said. “Amerindian people used it in many ways. Raw, the pulp was sucked.
The (cacao seed) could be cooked, roasted, grinded and made into liquid and solid foods. The bark, branches and the cob can be burned, and the ashes are an antiseptic. And it is also used to relieve skin or muscle inflammations and sores.