Tracking breastfeeding and weaning practices in ancient populations by combining carbon, nitrogen and oxygen stable isotopes from multiple non-adult tissues

PLoS One. 2022 Feb 2;17(2):e0262435. doi: 10.1371/journal.pone.0262435. eCollection 2022.

Abstract

This paper explores the potential of combining different isotope systems from different tissues to improve resolution when reconstructing breastfeeding and weaning practices (BWP) in archaeology. Additionally, we tested whether changes in diet can be detected in deciduous teeth. Rib collagen samples from 22 infants/children from the archaeological site of Bacuranao I (Mayabeque, Cuba) were processed for nitrogen (δ15N) and carbon (δ13Cco) stable isotopes and assessed using a Bayesian model (WARN). In addition, enamel of 48 teeth from 30 infants/children were analyzed for oxygen (δ18Oen) and carbon (δ13Cen) stable isotopes. Data revealed that the timing of weaning cannot be characterized precisely by analyzing either δ18O or δ15N. While a depletion in both δ15N and δ13Cco is only evident after one year, the WARN model suggested that the weaning process started at around 3 months and ended around 1.7 years. Most teeth were enriched in δ18Oen compared to deciduous incisors, suggesting a breastfeeding signal. However, a high variability in δ18O was found between similar teeth from the same individuals. Higher enrichment in δ18Oen, and variability, was observed in tissues formed during the first six months of life. A δ13C enrichment of 1.0‰ was observed among deciduous teeth and ribs. While most individuals enriched in δ15N showed enrichment in δ13C, the δ18O values were more variable. Our data suggests that stable isotopes of deciduous teeth, especially δ13Cen, can be used to detect changes in diet during the weaning process. It is also possible that the δ18O enrichment observed in M1 is influenced by the effects of cooking techniques on weaning foods. The combination of multiple isotope systems and tissues overcome some of the limitations posed by single tissue approaches.

Publication types

  • Historical Article
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Archaeology*
  • Bayes Theorem
  • Breast Feeding* / history
  • Carbon Isotopes / analysis
  • Collagen / chemistry
  • Cuba
  • History, Ancient
  • Humans
  • Nitrogen Isotopes / analysis
  • Oxygen Isotopes / analysis
  • Tooth, Deciduous / chemistry
  • Weaning*

Substances

  • Carbon Isotopes
  • Nitrogen Isotopes
  • Oxygen Isotopes
  • Collagen

Grants and funding

This research was funded by the Social Sciences and Humanities Research Council of Canada (YCA: SSHRC IDG 430-2020-01179) and the University of Winnipeg internal Major Grant (YCA). SSHRC (https://www.sshrc-crsh.gc.ca/funding-financement/programs-programmes/insight_development_grants-subventions_de_developpement_savoir-eng.aspx?cmp=1&wbdisable=true), University of Winnipeg (https://www.uwinnipeg.ca/research/docs/manual/major.pdf). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.