Compound specific isotope evidence points to use of freshwater resources as weaning food in Middle Neolithic Paris Basin

Abstract

Objectives A clear understanding of past weaning practices can provide invaluable insights into social issues such as infant care, fertility rate, and demographic patterns in past societies. This study presents the first archeological research employing compound specific isotope analysis (CSIA) for the reconstruction of past weaning practices. Methods Weaning practices of two Middle Neolithic communities in the Paris Basin region: Balloy (BLR) and Vignely (VPB), are evaluated by combining previously published bone collagen stable carbon, nitrogen, and sulfur (n = 66) isotope analysis with new compound specific carbon and nitrogen isotope compositions of bone collagen (n = 10). Results Our results demonstrate that the diets of individuals from BLR and VPB likely incorporated freshwater resources. The signals of freshwater resources consumption are even stronger among subadults, suggesting that freshwater resources were used as weaning food at these sites. Conclusions The implications of our result are threefold. Currently many CSIA studies in archeology only involve either carbon or nitrogen. Our data shows that it is important to conduct CSIA on both carbon and nitrogen for a more integrated picture. Secondly, our data demonstrates that the use of a protein‐based weaning food—instead of a starch‐based weaning food (such as cereal gruel)—was likely more prevalent among the Middle Neolithic communities in the Paris Basin Region than previously thought. The finding thus prompts a rethinking of the role of protein‐based weaning food in other archeological contexts. Lastly, the common assumption that weaning foods and adult diets share similar isotopic compositions can be problematic, as the use of protein‐based, high trophic‐level weaning foods can skew the δ15N weaning curve and produce an erroneously late estimation for weaning ages.

Diets, stress, and disease in the Etruscan society: Isotope analysis and infantile skeletal palaeopathology from Pontecagnano (Campania, southern Italy, 730–580 BCE)

“…According to secondary sources of Roman tradition [ 187 ], supplementary weaning foods included bread softened with hydromel or milk, soup made from spelt, moist porridge, and also eggs, known for their high protein content. However, as noted by Cheung et al [ 130 ], identifying the exact nature of weaned foods in past populations is a challenging task, especially when dealing with groups for whom little or no primary written sources have survived, like the Etruscans.…”

“…While reconstruction of weaning timing through stable nitrogen isotope analysis from bulk bone collagen has some issues (due to tissue turnover rates, enrichment factors, differential isotopic composition of weaning foods compared to adult foods, on this topic (e.g., [128][129][130]), the application of incremental dentine is, instead, widely accepted as a routine method for more robust investigations of past breastfeeding, weaning and childhood dietary practices (e.g., [96,97,102,104,[131][132][133][134][135]).…”

“…This cross sectional reconstruction fits with the adjusted WARN model that indicated the beginning of weaning at 0.7 years and completion at 2.6 years of age (S1 File). Based on this approach, studies have indicated that weaning in most archaeological populations for Bronze and Iron Age Europe, across various historical, cultural, and socio-economic contexts, started around 4-6 months and was completed around 2-3 years of age, occasionally extending up to 4 years [28,79,130,138,151,[186][187][188]. Nevertheless, despite achieving a relatively good approximation of weaning timing, the cross-sectional approach introduces challenges in interpretation.…”

Isotopic evidence of high reliance on plant food among Later Stone Age hunter-gatherers at Taforalt, Morocco

“… PCA plot of the δ 13 C Ala , δ 13 C Asp , δ 13 C Glx , δ 13 C Gly , δ 13 C Gly-Phe , δ 13 C Lys , δ 13 C Phe , δ 13 C Pro , δ 13 C val , δ 13 C Val-Phe measurement with bulk δ 13 C and δ 15 N values from Taforalt and published data 41 , 89 – 95 . …”

Proposed mechanism for the selection of lactase persistence in childhood

“…The diversity of food used for weaning may even participate in blurring the signal. [ 18 ] New approaches based on stable calcium isotope ratios are promising, but are still to be applied on Neolithic children. [ 19,20 ] Isotope analyses of European Neolithic cattle show that calves were weaned early, possibly because herders wished to increase the amount of milk available for human consumption.…”