This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: One of the world's favorite sweet treats, chocolate, may have been enjoyed in eastern North America much earlier than previously thought, about 1,000 years ago. New research published in the journal PLOS One suggests that people in the Mississippian city of Etowah were consuming cacao, the plant used to make chocolate, in the 11th and 12th centuries.
It was already known that cacao was being used in Central and South America thousands of years before European colonization. Scientists had also found evidence of cacao in the American Southwest, but there wasn't any clear evidence that people consumed chocolate in the great civilizations east of the Mississippi River. Researchers made their discovery after examining pottery sherds excavated from the Etowah Mounds.
This archaeological site in present-day Georgia features six large prehistoric earthen mounds as well as a village and plazas, and covers 54 acres (22 hectares) along the Etowah River. The team studied three 800- to 900-year-old Etowah pottery sherds recovered from feasting pits associated with the construction of the site's first platform mound. They sequenced the DNA found in the ancient residue taken from the pottery and compared it with the cacao genome.
Because these residues contain a mix of materials, the researchers also had to filter out DNA from other sources, such as soil bacteria, non-cacao plants and environmental contamination. Previous chemical tests on these same pottery residues found caffeine but couldn't prove cacao was present. That is because native plants like yaupon holly (Ilex vomitoria) contain some of the same chemical markers as cacao, including caffeine and theobromine, making it impossible for standard chemistry to tell the two plants apart.
Analyzing ancient DNA in the pottery residues provided more direct evidence of cacao. "Ancient DNA confirms the site's inhabitants consumed cacao," wrote the study authors in their paper. Finding cacao at Etowah helps improve our understanding of ancient North American trade.
Because cacao grows only in tropical regions, its presence in Georgia means it must have reached the region through contact with people in or near cacao-growing areas. The researchers say it may have arrived through long-distance networks that moved goods, people and ideas. However, they cannot say for sure where the cacao came from or the route it took.
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