Ancient corn farmers living in pit houses among arid canyons of what is now Utah may have sweetened their lives with a chocolate derivative imported from the tropics of Central America, recent archeological findings suggest.
An archeologist and team of chemists analyzing the remains of an eighth century village near present-day Moab found theobromine and caffeine, compounds found in a cacao tree native to Central America and from which chocolate is derived.
"We associate cacao use with the migration of corn farmers from Mexico into the Southwest," University of Pennsylvania archeologist Dorothy Washburn said on Friday.
But the new findings suggest that cacao, a bean that was ground up and used to flavor food and make drinks, may have arrived in the region hundreds of years earlier than previously thought, and from farther afield, she said.
The team analyzed roughly a half dozen polished and "very beautifully designed" ceramic bowls "with non-local designs" that belonged to farmers whose ancestors migrated north over centuries from parts of Central America, Washburn said.
The findings strongly suggest the bowls contained cacao, and predate earlier traces of cacao studied in jars and bowls found in masonry pueblos from the 11th and 12th centuries at Chaco Canyon, New Mexico, Washburn said.
The Utah study, to be published in April in the Journal of Archaeological Science, is not definitive because water swished around the bowls and then analyzed did not contain a third compound that could prove the existence of cacao, Washburn said.
"We looked for it but didn't detect it," said Washburn, who conducted the study in 2012 with husband William Washburn and his colleague, Petia Shipkova, both chemists at drug maker Bristol-Myers Squibb.
Michael Blake, an anthropology professor at the University of British Columbia in Vancouver, said cacao was an elite food in ancient times - the Aztec used cacao beans as currency - and the bowls analyzed in the study were likely from ordinary farmers.
"It is quite possible that it made its way up there as a precious trade item, part of a trade system of a wide range of precious commodities," Blake said.
The earliest evidence of cacao consumption dates back more than 3,000 years to southern regions of Mexico and Central America, Blake said. It cannot grow naturally in the Southwest United States.
Washburn said her team had also discovered cacao in ancient vessels analyzed near Collinsville, Illinois, which were used at the same time as those found in Chaco Canyon in New Mexico.
Washburn said the combination of theobromine and caffeine in the bowls from Utah suggested the existence of cacao, but the traces could also be from types of holly that grow along the Southeast United States Gulf coast and elsewhere.
(Reporting By Eric M. Johnson; Editing by Cynthia Johnston and Andrew Hay)