A diet rich in starch foods, such as pine nuts, may have led to high rates of tooth decay in ancient hunter-gatherers, according to a recent study.

Researchers from Oxford University, the Natural History Museum, London, and the National Institute of Archaeological Sciences and Heritage in Morocco found that dental issues, such as tooth decay, existed before the advent of farming - a view long-held by scholars - and had occurred in a hunter-gathering society in Morocco several thousand years "before the dawn of agriculture," according to a press release.

For their study, the team analyzed 52 sets of adult teeth from hunter-gatherer skeletons found in Taforalt in Morocco, dating between 15,000 and 13,700 years ago. They found evidence of decay in more than half of the surviving teeth, with three skeletons showing no signs of cavities.

"These people's mouths were often affected by both cavities in the teeth and abscesses, and they would have suffered from frequent toothache," Isabelle de Groote from the Natural History Museum said in a statement.

According to the press release, archaeological deposits at the site include a deep "ashy layer with exceptionally well preserved charred plant remains." Researchers found evidence of the systematic harvesting and processing of wild foods, including sweet acorns, pine nuts and land snails.

Louise Humphrey, human origins researcher at the Natural History Museum, said a reliance on the edible acorn could be the reason for the high prevalence of cavities in the teeth found at the research site.

"Eating fermentable carbohydrates is a key factor in the initiation and progression of this disease," he said. "The acorns may have been boiled or ground to make flour; cooking the acorns would have added to their stickiness, and abrasive particles from grindstones contributed to rapid tooth wear so that caries started to form on the roots of the teeth."

Prior to this study, many scholars believed that high rates of dental disease were associated with agricultural societies that grew domesticated plant crops.