Age‐related variation in isotopic indicators of diet at medieval Kulubnarti,Sudanese Nubia

This study compares trends in dietary composition in two large cemetery populations from the site of Kulubnarti (AD 550–800) in Sudanese Nubia. Bone collagen and bone apatite carbonate were analysed to characterise stable carbon, nitrogen and oxygen isotopes. Previous research on these cemeteries has suggested marked differences in nutritional status and health between the populations. Contrary to expectations, there were no significant relationships between any isotopic indicators related to sex or cemetery of burial, suggesting no isotopically‐measurable differences in diet. However, collagen δ¹³C and δ¹⁵N were significantly related to age, suggesting age‐related differences in protein intake or other factors. Weaning trends are gradual and variable, with the range in δ¹⁵N values exceeding 4‰ among infants/young children (0–3 yrs) and standard deviations exceeding 1‰ in collagen δ¹³C and δ¹⁵N for both infants/young children and subadults (4–17 yrs). This suggests varied weaning strategies among both populations and variable diets prior to adulthood. Also observed was a distinct range of isotopic carbon and nitrogen values among individuals classified as subadults (4–17 yrs), who are depleted in collagen δ¹³C and δ¹⁵N relative to adults. However, both infants/young children and subadults are slightly enriched in δ¹⁸O relative to adults, which suggests the presence of non‐local individuals or age‐related variation in water sources. While most isotopic studies of age‐related dietary trends have focused on reconstructing the weaning process, this study presents findings that indicate tripartite isotopic trends distinguishing infancy, subadulthood and adulthood as separate dietary categories. Broad similarities are evident between the results presented here and those from several earlier studies of smaller populations and to nutritional studies of modern communities. These findings suggest that further research into health disparities at Kulubnarti should focus on non‐dietary causal factors, and more generally, that greater attention should be paid to subadulthood in palaeodiet studies. Copyright © 2006 John Wiley & Sons, Ltd.     

Preliminary evidence for medieval Polish diet from carbon and nitrogen stable isotopes

In this pilot study, stable carbon and nitrogen isotopes from bone collagen and apatite of skeletons from the 11th and 12th century cemetery in Giecz, Poland are interpreted. Isotope values from a small number of fish and animal bones from the same archaeological site are also examined. The goal of this research is to provide preliminary evidence of diet for a group of medieval Polish peasants, with particular emphasis on sex-based differences in diet. Results of isotope analyses suggest diet of this early medieval population was omnivorous and terrestrial-based. Fish bones sampled exhibit low δ¹³C ratios, and in half of the cases are significantly enriched in ¹⁵N, indicating they are freshwater species. Human bones do not reflect these signatures, suggesting freshwater fish were not a significant source of dietary protein at Giecz. The ¹³C_coll from some human bones is enriched beyond what might be expected from an exclusively C₃ diet. Associated mammal bones do not exhibit similarly elevated δ¹³C_coll ratios, suggesting enrichment among humans is not due to consumption of animals foddered on C₄ plants. Two possible sources of ¹³C_coll enrichment are marine fish in diet and direct consumption of a C₄ plant, such as millet. The δ¹³C values obtained from bone apatite of a small subset of humans suggest that millet contributes to ¹³C_coll enrichment, although at least three individuals may have also consumed small amounts of marine fish. Sex-based differences in δ¹⁵N ratios indicate that men consumed relatively more animal products (meat or dairy) than did women. There is also a correlation between δ¹³C_coll and δ¹⁵N values in skeletons of men that is absent in women. These carbon and nitrogen isotope data are the first reported for any Polish population and contribute to a more complete picture of dietary adaptation and social organization in medieval Europe.     

Carbon and nitrogen stable isotope analysis on the diet of Jomon populations from two coastal regions of Japan

We report on a stable isotope paleodietary reconstruction of Jomon populations in Japan during the Middle to Final Jomon period (ca. 5000–2300 years BP), focusing on dietary differences within and among populations and between regions. Carbon and nitrogen isotope analysis was performed on human and faunal bone collagen from six coastal sites along the Inland Sea in the Sanyo (Ota, Funamoto, and Tsukumo) region and along Mikawa Bay and the Pacific Ocean in the Tokai (Kawaji, Yoshigo, and Inariyama) region. We found that carbon and nitrogen isotope ratios were positively correlated, indicating that the Jomon people consumed a mixed diet of marine (shellfish and marine fish) and terrestrial (C₃ plants and terrestrial mammals) protein. In the Ota samples (n = 25, during the Middle Jomon period, 5000–4000 years BP), sex was one of the main reasons for the intra-population dietary variation. Ota males consumed greater amounts of marine food, while Ota females consumed greater amounts of terrestrial food; these dissimilar diets may have been related to the sexual division of labor. Significant inter-population dietary differences were found, which may have been related to differences in age or site location. Notably, the two coastal regions showed clear isotopic differences. Nitrogen isotope ratios of individuals from the Sanyo region were significantly higher than ratios of individuals from the Tokai region. The individuals in the Sanyo region might have consumed a diet high in aquatic foods, particularly high trophic level marine fish, whereas the individuals in the Tokai region might have consumed a lot of marine shellfish. Another possible reason for the regional isotopic difference might have been different baseline of nitrogen isotope ratios of the marine ecosystems.     

Dietary patterns during the late prehistoric/historic period in Cikobia island (Fiji): insights from stable isotopes and dental pathologies

The dietary patterns of eight adults and one child interred in the Korotuku burial mound (Cikobia, northern Fiji), dated from the late prehistoric/historic period (around AD 1850), have been investigated using carbon and nitrogen stable isotope signatures and dental and oral pathologies. Bone collagen isotopic compositions showed that (1) males and females had similar diets in terms of terrestrial C₃ resources and marine fish components and proportions; (2) the proportion of marine fish comprised around 25% of the protein fraction of the diet, and the proportion of vegetal food was high; and (3) one canid that was also studied had a different diet, probably rich in shellfish. Oral and dental examinations of the humans evidenced (1) a low level of dental macrowear, (2) a high rate of carious lesions—interproximal and cervical—of about 15%, and (3) a low amount of abscessing, as well as the presence of alveolar bone recession and calculus in most of the adults. This evidence suggests a diet relying mainly on vegetal food with very limited shellfish consumption. When viewed in the light of ethnohistoric information, this pattern suggests a particular sociocultural behaviour, including food selection, since the analyses of the canid remains indicate that more diversified food resources were available than those consumed by the humans. Overall observations suggest that the deceased in the Korotuku burial mound might be members of an elite living on the island, thus pointing to possible social stratification in the late prehistoric/historic Cikobia community.     

Prehistoric Fijian diet and subsistence: integration of faunal, ethnographic, and stable isotopic evidence from the Lau Island Group

We explore subsistence practices and dietary change on islands in the central Lau Group of Fiji with zooarchaeological methods and stable isotopic analysis of human and animal skeletal material interpreted through an ethnoarchaeological lens. Our dataset combines detailed identifications of fauna, especially fishes, with stable isotopic (δ¹³C, δ¹⁵N) values of human and animal bone collagen and apatite carbonate spanning approximately three thousand years of human occupation on three study islands. Additionally, over fifty inshore and offshore contemporary fishing expeditions were observed on all study islands over a six-year period. We integrate these separate lines of evidence to form robust interpretations of Lauan subsistence patterns over a broad temporal scale. We add to the existing literature on stable isotopic analysis of archaeological bone from Remote Oceania and compare all of these groups through time. Our results indicate that Lauans differentially relied on nearshore reef resources rather than pelagic fishes, and terrestrial endemic species may have served as a portion of the diet during the early prehistoric period. Root crops (e.g., taro, yam) provided the majority of calories to the diet; however, sea grapes likely contributed to the early diet. Our isotopic results differ from previous studies of Fijian diet and that of Remote Oceania at a time of probable marine ecosystem shifts (AD 1300) illustrating diet breadth and variability in subsistence strategies potentially due to climatically influenced resource depletion.     

A calf for all seasons? The potential of stable isotope analysis to investigate prehistoric husbandry practices

The Early Bronze Age barrows at Irthlingborough and Gayhurst in central England are notable for the large number of cattle (Bos taurus) remains associated with their human Beaker burials. Previous work using strontium isotope analysis has indicated that most of the cattle analysed, and one aurochs (Bos primigenius), were of local origin [Towers, J., Montgomery, J., Evans, J., Jay, M., Parker Pearson, M., 2010. An investigation of the origins of cattle and aurochs deposited in the Early Bronze Age barrows at Gayhurst and Irthlingborough. Journal of Archaeological Science 37, 508–515.]. In this study, stable isotope analysis of enamel and bone was carried out to investigate whether the mature cattle had experienced similar husbandry practices, climate and environment. Bulk carbon, nitrogen and sulphur isotope analysis of collagen suggested most were consuming similar sources of plant protein from environments probably local to the sites and this was supported by high resolution intra-enamel carbon isotope profiles. Oxygen isotope profiles indicated the aurochs and most of the cattle experienced similar climatic regimes: the only exception being an animal with a non-local strontium isotope ratio. However, a comparison of seasonality profiles of the local animals using estimated tooth formation times showed that there was no consistency in season of birth: the animals appeared to have been born throughout the year. Cattle can breed throughout the year but it requires considerable human effort and intervention to successfully overwinter young stock; it is therefore unlikely to have been carried out without good reason and benefit if winters were harsh. One reason is to ensure a continuous supply of milk. Measuring oxygen isotope profiles to identify year-round calving may thus be a potential indicator of dairying economies.     

Multiple Microanalyses of a Sample from the Vinland Map

A sample of the Vinland Map remaining from the radiocarbon dating was analysed with the purpose of identifying the post‐1950 contaminant and establishing other evidence on the material composition, identity and condition. The analyses revealed that the parchment originates from a bovid and contains hair remnants. The fibre structure was in poor condition, with fragmented collagen fibres and a low hydrothermal stability. Greenish and reddish particles were observed on the parchment. The greenish particles were identified as basic copper(II) chloride, most probably atacamite, and the reddish particles as rust; that is, various iron(III) oxides. The extracted modern contaminant was identified as being naturally produced glycerol monostearate.     

A Simple(R) Model to Predict the Source of Dietary Carbon in Individual Consumers

Quantitative individual human diet reconstruction using isotopic data and a Bayesian approach typically requires the inclusion of several model parameters, such as individual isotopic data, isotopic and macronutrient composition of food groups, diet‐to‐tissue isotopic offsets and dietary routing. In an archaeological context, sparse data may hamper a widespread application of such models. However, simpler models may be proposed to address specific archaeological questions. As a consequence of the intake of marine foods, individuals from the first century ad Roman site of Herculaneum showed well‐defined bone collagen radiocarbon age offsets from the expected terrestrial value. Taking as reference these radiocarbon offsets and using as model input stable isotope data (δ¹³C and δ¹⁵N), the performance of two Bayesian mixing model instances (routed and concentration‐dependent model versus non‐routed and concentration‐independent) was compared to predict the carbon contribution of marine foods to bone collagen. Predictions generated by both models were in good agreement with observed values. The model with higher complexity showed only a slightly better performance in terms of accuracy and precision. This demonstrates that under similar circumstances, a simple Bayesian approach can be applied to quantify the carbon contribution of marine foods to human bone collagen.     

The Whole Tooth and Nothing but the Tooth: Or why Temporal Resolution of Bone Collagen May Be Unreliable

The carbon (δ¹³C) and nitrogen (δ¹⁵N) isotope ratios of human bone collagen have been used extensively over the last 40 years to investigate the diet of past populations. It has become apparent that bone collagen can give an unreliable temporal dietary signature especially in juveniles. With higher temporal resolution sampling of collagen from tooth dentine, it is possible to identify short-term changes in diet previously invisible in bone. This paper discusses the inherent problems of using bone collagen for dietary studies and suggests better sample choices, which can make our interpretations more robust, using breastfeeding and weaning as an example.     

Adding Hydrogen to the Isotopic Inventory—Combining δ13C, δ15N and δ2H Stable Isotope Analysis for Palaeodietary Purposes on Archaeological Bone

Few papers using hydrogen stable isotope analysis for human palaeodietary reconstruction purposes have been published and the usefulness of this additional dietary indicator is highlighted here. The hydrogen stable isotope results provide evidence for the continued exploitation of aquatic resources throughout the prehistory of the Limfjord area in Denmark, which is supported by FRUITS estimates using three (CNH) isotopic proxies. While aquatic dietary input has been identified in Mesolithic and Viking Age individuals before, our results show that, in fact, this continued throughout the periods in between (Neolithic, Bronze and Iron Age), albeit on a small scale.