Infant mortality and isotopic complexity: New approaches to stress, maternal health, and weaning

Abstract

M (2015) Infant mortality and isotopic complexity: new approaches to stress, maternal health and weaning. American Journal of Physical Anthropology. 157(3): 441-457, which will be published in final form at http://dx.doi.org/10.1002/ ajpa.22736. Materials and MethodsChildhood dentine collagen  13C and  15N profiles were produced from horizontal sections of permanent and deciduous teeth following the direction of development. These were from two 19 th -century sites (n = 24) and a small number (n = 5) of prehistoric samples from Great Britain and Ireland. ResultsThese high-resolution data exhibit marked differences between those who survived childhood and those who did not, the former varying little and the latter fluctuating widely. DiscussionBreastfeeding and weaning behavior have a significant impact on the morbidity and mortality of infants and the adults they become. In the absence of documentary evidence, archaeological studies of bone collagen of adults and juveniles have been used to infer the prevalence and duration of breastfeeding. These interpretations rely on certain assumptions about the relationship between isotope ratios in the bone collagen of the adult females and the infants who have died. The data from this study suggest a more complex situation than previously proposed and the potential for a new approach to the study of maternal and infant health in past populations. 3Carbon and nitrogen stable isotope ratios from archaeological bone and dental tissues have been used for more than 20 years to investigate breastfeeding and weaning practices. Early studies, which revolutionized the use of bone collagen stable isotopes, identified patterns within the tissues of fetuses (less than 28 weeks gestation), neonates (28-40 weeks gestation) and infants (28 days to 1 year post-birth)(Lewis and Gowland 2007) which revealed the potential to investigate the duration of breastfeeding and weaning in past populations (e.g. Fogel et al. 1989;Katzenberg et al. 1993;Schurr 1997;White and Schwarcz 1994). Katzenberg (1996) reviewed previous interpretations of the method and cautioned against the potential effect of using the tissues of dead infants without knowing the cause of death and the potential for stress, bone turnover and growth to alter the isotope ratios of both mother and infant. Subsequently, a simplified method, based on a mathematical model of the isotope ratio variations which should be associated with a dietary change from breastmilk to the prevailing diet of the adult population, was proposed and widely accepted (Schurr 1997;Millard, 2000;Jay, 2008). This method has since been applied to data from modern, historical and archaeological tissues to estimate the timing of weaning and whether breastfeeding occurred over prolonged periods.The mathematical model has been used pragmatically despite the often-acknowledged fact that it makes several assumptions about the relationships of mother and infant body tissues, their diets, and the comparability of individual members of a population with the o...

Isotopic anthropology of rural German medieval diet: intra- and inter-population variability

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