Can dental caries be interpreted as evidence of farming? The Asian experience

The seminal development of control of food production and its social and biological effects on human populations has for a long time been one of the foci of prehistoric research. The relationship between diet and oral pathology is well recognised and accepted to the point where rates of dental caries in particular have been seen as indicative of subsistence mode. This is despite the complex aetiology of caries, with both genetic and environmental factors other than diet contributing to lesion frequency. Most publications considering prehistoric diet and caries acknowledge the contribution of non-dietary variables but provide a more comfortable dietary explanation, with the role of domesticated starchy staples paramount. This widespread acceptance of a simple relationship between dental pathology and starchy carbohydrates needs to be challenged, as there is no reason why one dietary component would be solely responsible for the development of caries or why all carbohydrates should have the same effect. Some years ago, on the basis of evidence from prehistoric rice farming communities in Southeast Asia, we questioned the relationship between dental caries and the presumptive increased carbohydrate consumption consequent to the adoption of agriculture. This paper reviews recent literature on the topic and presents evidence that there is still no simple or universally applicable explanation for patterns of changes in caries frequencies during human prehistory.