Weaning and infant mortality: Evaluating the skeletal evidence

Abstract

Studies of prehistoric patterns of health and disease focus on interpretations of the evidence from hard tissue remains of past peoples. These interpretations are based on observations of living peoples and the sources of stress which may be expected to leave a record in their bones and teeth. One presumed source of stress that has received wide attention in the recent literature is weaning. The process of weaning is often associated with elevated risks of infant mortality and morbidity because infants no longer receive passive immunity from their mothers, and they are exposed to new sources of infection through the weaning diet. The process of weaning has also been tied to the duration of the contraceptive effects of nursing and the return of fecundity, which in turn provides information about birth spacing and population growth. Recently some of the basic assumptions about nursing and weaning, and their effects on morbidity, mortality and population growth, have been challenged, based on new technical and cross-cultural information. It is clear from the demographic literature that some studies based on skeletal samples tend to be too simplistic in terms of the causes of infant morbidity and mortality. This paper reviews current research which relates weaning and infant mortality to health and reproduction in past populations and evaluates studies of enamel hypoplasia and bone chemistry for reconstructing infant feeding practices in the past. o 1996 WiIey-Liss, Inc.

Sex‐biased weaning and early childhood diet among middle holocene hunter–gatherers in Central California

“…A child that is completely dependent on breast milk for protein will display enriched d 15 N over its mother by one trophic level, as has been shown in both controlled studies as well as in archaeological studies of human bone collagen of infants (Fogel et al, 1989;Katzenberg et al, 1996;Schurr, 1997;Herring et al, 1998;Fuller, et al 2006aFuller, et al ,2006bNehlich et al, 2011). However, as a child is weaned on solid foods, d…”

Multi-isotopic analysis of first Polynesian diet (Talasiu, Tongatapu, Kingdom of Tonga)

“…The three subadults exhibit distinctive δ 13 C col and δ 15 N values compared to adults. The youngest child (Sk11), aged between 1.5 and 2.5 years, show the highest δ 13 C col and δ 15 N values and the results could favor a hypothesis that he/she was breastfed at the time of death (Katzenberg et al, 1996). The tissue of a breastfed baby can be respectively enriched by +2-4‰ and 1‰ in 15 N and 13 C during the consumption of the mother's milk (Fogel et al, 1989;Fuller et al, 2006).…”

Reconstruction of breastfeeding and weaning practices using stable isotope and trace element analyses: A review

“…This phenomenon is called the 'osteological paradox' and occurs in studies using either archaeological subadult or adult skeletons (Wood et al, 1992;Katzenberg et al 1996;Lewis, 2007). Isotopic and trace elemental signals from subadult skeletons represent BWPs in dead individuals rather than those in healthy individuals who survived into adulthood.…”

“…Infant feeding practices affect the overall health of the population because diet, health status, and growth at a young age have profound effects on an individual's later life (Dettwyler and Fishman, 1992;Katzenberg et al, 1996;WHO, 1998WHO, , 2009Lewis, 2007). Breastfeeding and weaning practices can be viewed from the evolutionary perspectives of life history theory, parental investment, child development, social system, and reproductive strat-…”