中国古代儿童断奶模式与喂养方式初探——以安徽薄阳城遗址人骨的C、N稳定同位素分析为例

了解古代儿童的断奶模式和喂养方式,可望为揭示古代儿童的营养状况、生长发育以及其死亡原因提供有价值的重要信息。近些年来,通过对古代儿童骨骼的C、N稳定同位素分析,重建古代儿童的断奶模式和喂养方式,成为国际生物考古界的研究前沿,但在我国尚无任何相关报道。为此,本文以安徽滁州薄阳城遗址人骨(包含不同年龄阶段的儿童和成年人)样品为研究材料,通过对同一个体肋骨和肢骨的C、N稳定同位素分析和比较,重点探讨了我国西周时期儿童的断奶模式及喂养方式。研究结果显示:儿童在2岁已有辅食的摄入,大多数儿童在3-4岁已经完成断奶;断奶后的儿童,其食物中包含更多的植物作为辅食。本研究,印证了我国历史文献中有关儿童喂养模式的最早记载(唐代孙思邈的医书《千金方》),也为系统探索我国古代儿童的断奶模式和喂养方式提供了很好的范例。

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Investigation of children breastfeeding/weaning practices and feeding practices in the past have become one of hotspot in the international bioarchaeological fields. However,there has been no similar research undertaken in China. Here we investigated the breastfeeding and weaning patterns as well as children feeding practices at the Western Zhou Dynasty site of Boyangcheng located in Chuzhou, Anhui Province, China. In addition, we utilize the differences in bone collagen turnover rates between rib and long bones from the same individual to examine past life histories, such as changes in diet or residence. Bone collagen from both the rib and long bones (either femurs or humeri) of 42 individuals was measured for stable isotope ratios of carbon (δ13C) and nitrogen (δ15N). The human δ13C values range from -20.7‰ to -12.0‰ with a mean value of –18.8‰±1.6‰. The human δ15N values range from 9.1‰ to 13.4‰ with a mean value of 10.9‰±1.0‰. The δ13C and δ15N results reflect that solid foods were introduced to the infant’s diet before the age of 2 years, and that the elevated children δ15N results returned to adult levels by approximately 3-4 years of age, indicating that the weaning process was completed during this period. Individuals between 2-10 years old, with lower δ13C and δ15N results than the adult mean, possibly consumed more plant-based diets, and this is consistent with Chinese medical teachings ~1500 years later during the Tang Dynasty (618~907 AD). The isotopic offsets between the ribs and long bones revealed that five adults experienced dramatic dietary shifts in their later lives, switching from predominately C4/C3 to C3 diets. This research provides the first isotopic information about ancient Chinese breastfeeding and weaning practices and a good example for future studies to examine diachronic trends of feeding practices of ancient children in China.