Museum study shows earlier processing of carbohydrates caused dental problems for ancient humans.
Research led by Museum scientists suggests a diet rich in starchy foods may have caused high rates of tooth decay in ancient hunter-gatherers.
The results published today in US journal PNAS (Proceedings of the National Academy of Sciences) also suggest tooth decay was more prevalent in earlier societies than previously estimated.
The results also suggest that the hunter-gatherer society studied may have developed a more sedentary lifestyle than previously thought, relying on nut harvesting.
Dental disease was thought to have originated with the introduction of farming and changes in food processing around 10,000 years ago. A greater reliance on cultivated plant foods, rich in fermentable carbohydrates, resulted in rotting teeth.
Now, the analysis of 52 adult dentitions from hunter-gatherer skeletons found in a cave in Taforalt, Morocco dating from between 15,000 and 13,700 years ago suggests people suffered tooth decay in much earlier times.
Evidence of decay was found in more than half of the teeth that were intact, with only three skeletons showing no sign of cavities.
Museum palaeobiologist Isabelle De Groote, who studied the teeth, said: 'These people's mouths were often affected by both cavities in the teeth and abscesses, and they would have suffered from frequent toothache.'
Archaeological excavations at the site in Taforalt, including elaborate human burial areas, showed evidence of methodical harvesting and processing of wild foods, including sweet acorns, pine nuts and land snails.
Museum human origins expert Dr Louise Humphrey said a staple diet of edible acorns could have been the cause of the dental disease.
'The acorns may have been boiled or ground to make flour; cooking the acorns would have added to their stickiness,' Dr Humphrey said.
Dr Humphrey also speculated that these Pleistocene hunter-gatherers may have pulled out their own teeth.
Skeletons at Taforalt reveal that most people practiced tooth evulsion, whereby one or two healthy incisors were deliberately removed in late childhood or early adulthood. This would have been for cultural reasons, such as indicating group affiliation or as a rite of passage.
The same skills could have been used to extract diseased teeth and relieve dental pain.