Archaeol. Res. Asia | Dental Caries in Prehistoric Populations and Agricultural Development in the Foothill Zones of Northern and Southern China

Recently, the Center for Archaeological Sciences, Sichuan University, in collaboration with the University of Cambridge, Chengdu Municipal Institute of Cultural Relics and Archaeology, Zhengzhou Municipal Institute of Cultural Relics and Archaeology, Jilin University, and other research institutions, published a research paper titled "Dental caries as indicators of agricultural practices in the foothills of Neolithic China" in the international journal *Archaeological Research in Asia*. The first author of the paper is Cao Doudou, and the corresponding author is Yuan Haibing from the Center for Archaeological Sciences, Sichuan University. Co-authors include Liu Xiangyu, Zhou Zhiqing, and Chen Jian from the Chengdu Municipal Institute of Cultural Relics and Archaeology; Gu Wanfa, Wei Qingli, and Ding Lanpo from the Zhengzhou Municipal Institute of Cultural Relics and Archaeology; Zhu Hong from the School of Archaeology, Jilin University; Zhang Ruojing, Zou Jiaxing, and Qiu Yujie from the School of Archaeology and Museology, Sichuan University; and Emma Pomeroy from the Department of Archaeology, University of Cambridge.

This study focuses on three archaeological sites in the foothill zones of China during the middle to late Neolithic period (c. 5500 to 3700 BP): the Niuheliang site (Hongshan culture) in western Liaoning, the Qingtai site (Yangshao culture) in the middle reaches of the Yellow River, and the Gaoshan ancient city site (Baodun culture) on the western edge of the Sichuan Basin. Using the prevalence of dental caries as a starting point, the study explores the interactive relationship between the subsistence strategies, environmental adaptations, and oral health of prehistoric populations.

Distribution map of the main sites involved in this study

By observing and recording 2,885 teeth from 149 adult individuals, and analyzing them in conjunction with factors such as sex and age, the results show that the hunter-gatherer population from Niuheliang had the lowest prevalence rates for both individuals (26.70%) and teeth (3.40%). The rice-millet mixed agricultural population from Gaoshan ancient city had slightly higher rates (individual prevalence 36.10%, tooth prevalence 4.90%), while the millet-based agricultural population from Qingtai had the highest rates (individual prevalence 75.90%, tooth prevalence 14.00%).

Distribution of caries prevalence in various middle and late Neolithic populations

Different subsistence patterns not only influenced people's choice of staple foods but also profoundly shaped their dietary culture and social structure. During the middle to late Yangshao culture in the Central Plains, agriculture had become highly intensive. People widely used grain processing tools such as stone grinders and storage vessels, and a large number of wine vessels also appeared. The diet likely included highly adhesive soft foods such as millet porridge and fermented beverages. While these foods increased energy intake efficiency, they also exacerbated the risk of developing caries. In comparison, although the population of Gaoshan ancient city, located on the western piedmont edge of the Sichuan Basin, was primarily based on rice agriculture, their food composition was more diverse: the remains of wild animal bones, wild fruits, and millet all indicate a more varied and balanced dietary structure. A diversified dietary structure reduced their dependence on a single high-carbohydrate crop, thereby lowering the risk of caries. The Niuheliang population, primarily hunter-gatherers, also had a diverse diet with relatively lower intake of starchy foods, which supports their lower caries prevalence.

Examples of caries at different locations on teeth

a: Occlusal caries; b: Alveolar resorption after the intentional artificial removal of maxillary lateral incisors in the Gaoshan ancient city population; c: Mesial interproximal caries.

The caries prevalence in females from the prehistoric Qingtai population was slightly higher than in males. This sex-based difference may be related to factors such as the division of labor by gender in prehistoric society, dietary habits, oral microenvironment, physiological differences, or resource allocation. This suggests that caries formation is not only related to dietary structure but is also likely influenced by a combination of social behaviors and biological factors.

This study explores the relationship between the occurrence of dental caries and subsistence patterns among prehistoric populations in China's foothill zones. It reveals that the connection between agricultural development and population oral health is not a simple linear causal relationship, but rather the result of the combined effects of multiple factors, including crop types, food processing methods, social structure, and ecological adaptation. Furthermore, different crop types (such as millet and rice, even though both are core agricultural crops) may also differ in their cariogenic mechanisms. This cross-regional and cross-cultural comparative study not only enriches our understanding of the lifestyles and health status of prehistoric populations in China but also provides a new perspective for understanding 'human-land interactions'.