Individual dietary patterns during childhood: an archaeological application of a stable isotope microsampling method for tooth dentin

Abstract

Diet from the late medieval Fishergate House cemetery site (York, UK) is reconstructed using nitrogen and carbon stable isotope ratio analysis from tooth dentin. Deciduous teeth from 42 subadult individuals (fetal to 5–6 years) were used to reconstruct weaning practices at a population and an individual level. This is the first archaeological use of this microsampling method (dentin ≥.3 mg). This method allows an individual's changing diet to be reconstructed from the fetal period through weaning. The fetal signals show a complicated relationship with adult female ratios, having higher δ15N values than expected. At this site, there is an unusual decoupling between peak mortality (4–6 years) and weaning (2 years). The mean δ15N ratios for weaned children were enriched when compared to the adult females (12.4‰ ± 1.29 and 11.4‰ ± 1.1; statistically significant to p < .05). Early childhood diet is surprisingly high in marine fish and/or pork given the low socioeconomic class of the sample. This is a departure in weaned diet from contemporary communities and may be responsible for the unusual disconnect between peak mortality and weaning. When the individual dietary reconstructions were combined with each individual's rib reconstruction the presence of a true child specific diet was clear starting at approximately 2 years of age. Some individuals diverge from the population norm and have an extended breastfeeding period linked to poor health. The increased resolution of microsampling allows bioarchaeologists to test detailed time depended questions about early childhood diet and health.