Isotopic Evidence for Breastfeeding and Possible Adult Dietary Differences from Late/Sub-Roman Britain

Abstract

Historical documents indicate that breastfeeding and weaning practices have fluctuated in England through history. In order to obtain evidence for general breastfeeding patterns in Late/Sub-Roman Britain, stable carbon and nitrogen isotope values were measured in juvenile and adult skeletons (n = 87) from the cemetery of Queenford Farm, Dorchester-on-Thames, Oxfordshire. As the site contained few individuals between 0-1.5 years of age, it was not possible to determine the initial timing for the introduction of weaning foods. Between ages 2-4 years, the mean +/- SD delta(13)C results (-20.2 +/- 0.3 per thousand) are significantly more negative (t = -4.03, P < 0.001) compared to adult females (-19.7 +/- 0.3 per thousand). This is interpreted as evidence of a different diet being fed to children during weaning. After age 2, the delta(15)N values gradually decline, indicating complete cessation of breastfeeding by 3-4 years. Among adults, stature (males = 1.68 +/- 0.06 m; females = 1.58 +/- 0.07 m) and sexual dimorphism (106) were low, suggesting that the population was possibly under environmental stress. The delta(13)C results for adults are similar, but females show a small but statistically significantly (t = -2.86, P < 0.01) lower mean delta(15)N value (9.9 +/- 0.9 per thousand) compared to males (10.6 +/- 0.5 per thousand). These lower female delta(15)N values possibly reflect the different physiology of the sexes (pregnancy and/or lactation) or the reduced consumption of animal/fish protein by women, and this may have been influenced by individual preference, family needs, or societal values of the era.

Stable isotope and multi-analytical investigation of Monte da Cegonha: A Late Antiquity population in southern Portugal

“…They reported that supplementary foods (boiled honey or a mixture of honey and goat's milk) were introduced gradually at 6 months of age, with complete termination of breastfeeding by 3 years of age. During the weaning process, the introduction of supplementary foods results in a gradual depletion of infant δ 15 N, reaching adult values when the child is fully weaned (Dupras et al, 2001;Fuller et al, 2006). Average enrichment in bone δ 13 C co and δ 15 N values of the humans analysed (at approximately 1.5‰ and 3.8‰, respectively), is consistent with a trophic level enrichment between herbivores and carnivores.…”

“…The δ 15 N collagen ratios of four other infants analysed (HMC 3, 4, 16 and 17; aged 38 weeks in uterus-1.5 months, 6 months-1 year, three and five years old) plot closely to the adult isotope ratios, suggesting that these individuals were either not breastfed or had already been weaned (Budd et al, 2013). Weaning practices of the Roman era were described by Soranus and Galen, medical scholars of the Roman world (2 nd century AD) (Dupras et al, 2001;Fuller et al, 2006). They reported that supplementary foods (boiled honey or a mixture of honey and goat's milk) were introduced gradually at 6 months of age, with complete termination of breastfeeding by 3 years of age.…”

“…This δ 15 N enrichment seems to indicate a nursing signal. Some authors have addressed the issue of breastfeeding and weaning practices by analysing teeth (Richards et al, 2002;Beaumont et al, 2013Beaumont et al, , 2015 while others have investigated bone samples (Dupras et al, 2001;Fuller et al, 2006;Jørkov et al, 2010). In this study, breastfeeding and weaning was investigated using bone samples as teeth were not available for infant.…”

“…In this study, breastfeeding and weaning was investigated using bone samples as teeth were not available for infant. When infants are breastfed, all protein is obtained from their mother's milk (Dupras et al, 2001), and thus δ 15 N values of the infant's collagen reflect a trophic shift of 2 to 3‰ compared to the mother (Dupras et al, 2001;Fuller et al, 2006). The δ 15 N collagen ratios of four other infants analysed (HMC 3, 4, 16 and 17; aged 38 weeks in uterus-1.5 months, 6 months-1 year, three and five years old) plot closely to the adult isotope ratios, suggesting that these individuals were either not breastfed or had already been weaned (Budd et al, 2013).…”

Eating out or dining in: modeling diverse dietary strategies in the Middle Period, San Pedro de Atacama, Chile

“…While the plant diet of this individual was near the average value of all individuals presented here (32.3 ± 12.8 % C 3 , 32.8 ± 7.3 % C 4 ), the model indicates that they were consuming more terrestrial mammal meat (as compared to legumes) than any of the other analyzed individuals. In part, at least, the high modeled value for terrestrial mammal meat could be a consequence of an elevated δ 15 N co signature (15.0 ‰) resulting from the residual effects of breastfeeding (see, for example, Fuller et al 2006). It is worth noting, however, that this individual was also buried with an entire juvenile camelid and a hallucinogenic snuff tray with Tiwanaku iconography depicting a camelid carrying a bundle, possibly including plants (Fig.…”