Oxygen isotope analysis of human bone phosphate evidences weaning age in archaeological populations

Abstract

Here we report bone phosphate oxygen (δ(18)Op) values from perinates/neonates and infants (<3.5 years; n = 32); children (4-12 years; n = 12); unsexed juveniles (16-18 years; n = 2); and adult bones (n = 17) from Wharram Percy, North Yorkshire, England, in order to explore the potential of this method to investigate patterns of past breastfeeding and weaning. In prior studies, δ(15)N and δ(13)C analyses of bone collagen have been utilized to explore weaning age in this large and well-studied assemblage, rendering this material highly appropriate for the testing and development of this alternative method targeting the inorganic phase of bone. Data produced reveal (18)O-enrichment in the youngest perinatal/neonatal and infant samples, and an association between age and bone δ(18)Op (and previously-published δ(15)N values), with high values in both these isotope systems likely due to breastfeeding. After the age of 2-3 years, δ(18)Op values are lower, and all children between the ages of 4 and 12, along with the vast majority of sub-adults and adults sampled (aged 16 to >50 years), have δ(18)Op values consistent with the consumption of local modern drinking water. The implications of this study for the reconstruction of weaning practices in archaeological populations are discussed, including variations observed with bone δ(15)Ncoll and δ(18)Op co-analysis and the influence of culturally-modified drinking water and seasonality. The use of this method to explore human mobility and palaeoclimatic conditions are also discussed with reference to the data presented.

Land use and mobility during the Neolithic in Wales explored using isotope analysis of tooth enamel

“…The deciduous molars of two children sampled by this study (from Penywyrlod) have not been included in the above comparison of oxygen isotope ranges, as they begin formation in utero (AlQahtani et al, 2010) and, following birth, values within these teeth may be influenced by consumption of breast milk, which has a higher δ 18 O value relative to fluids consumed by the mother (Britton, Fuller, Tütken, Mays, & Richards, 2015; Roberts et al, 1988; Wright & Schwarcz, 1998). The deciduous second molar of child 74.23H/9.18/P20 from Penywyrlod (Figure 5) exhibits the highest δ 18 O carbonate value (28.2 ‰; δ 18 O phosphate 19.4 ‰) of all the individuals sampled in the present study: the possibility that this is a consequence of breastfeeding cannot be excluded.…”

“…759) argue to represent occupation of western Britain. However, as formation of deciduous molars continues in the months following birth, it is possible that oxygen isotope ratios in enamel from these teeth could also be influenced by consumption of breast milk, which may confer higher δ 18 O values than drinking water (Britton et al, 2015; Roberts et al, 1988; Wright & Schwarcz, 1998). The remains of this individual, dated to 1670–1500 cal BC (95% confidence; SUERC‐57789), were found outside Chamber 2 of the long cairn (Table 1).…”

From cradle to grave: multi-isotopic investigations on the life history of a higher-status female from Edo-period Japan

“…18 O values of exclusively breastfed infants seem to increase 2-3‰ (Roberts et al, 1988), stable isotope analysis of oxygen is also used for the reconstruction of weaning ages, as in the case of nitrogen (Wright and Schwarcz, 1998;Britton et al, 2015).…”

Child Bioarchaeology: Perspectives on the Past 10 Years

“…Carbon and nitrogen isotopes are also used to investigate components of the supplementary weaning and childhood diet. Recently, bone phosphate oxygen isotope methods have been developed (Britton et al 2015), which may complement multi-component isotopic studies. The traditional / standard sampling methods of bone of infants and children for the analyses of weaning produces a cross-sectional assessment of isotopic ratios of the non-survivors of the sample (e.g.…”