Temporal changes in diet: a stable isotope analysis of late Iron Age and Roman Dorset,Britain

This study investigates the relationship between diet and cultural change in late Iron Age and Romano-British populations from Dorset, England (1st century BC to the early 5th century AD). Dorset was the only region in Britain to exhibit continuity in inhumation burial rites through these periods and a wide array of environmental, archaeological and material culture evidence is available there. A sample of N = 77 human adult and N = 17 faunal rib samples were utilized for carbon and nitrogen stable isotope analysis to test the hypothesis that Romanization of the diet would result in greater dietary variation.     

FOCUS: effect of diet and protein source on carbon stable isotope ratios in collagen: follow up to

We analyzed carbon stable isotope data from bone collagen of animals consuming varied experimental diets, including recently published data from Warinner and Tuross [Warinner, C., Tuross, N., 2009. Alkaline cooking and stable isotope tissue–diet spacing in swine: archaeological implications. Journal of Archaeological Science 36, 1690–1697; this journal]. Comparing regression lines for the relationship between collagen and diet δ¹³C, we show that protein source, and not physiology, explains the apparent taxonomic difference between swine and rodents reported in that paper. Our results reveal a complex relationship between whole diet and dietary protein in determining collagen δ¹³C values, such that in many cases, collagen alone may not provide reliable reconstructions of paleodiet. We advocate the simultaneous use of both collagen and apatite δ¹³C, whenever possible, to assess the diets of prehistoric peoples.     

Stable isotope analysis of humans from Xiaojingshan site: implications for understanding the origin of millet agriculture in China

Millet agriculture originated in Northern China in the early Neolithic period (ca. 8000 BP), however, the actual importance of millet in human diets is still not clear. To determine the relative contribution of millet in human diets in this period we undertook stable isotope analysis of humans from Xiaojingshan site and fauna from Yuezhuang site, both of which are attributed to the Houli Culture and date to about 8000 years ago. The carbon isotope values of human bone collagen showed that millet (as a C₄ plant) only contributed approximately 25% of dietary protein, with the rest from C₃ based plant and animal sources, if a simple mixing model is used. We did not observe any statistical dietary difference between males and females at the site, although it has been argued that the Houli Culture was a matriarchal society. Finally, we compared our data with other published isotopic data from the contemporary Jiahu site and Xinglongwa site and a number of sites from the subsequent Yangshao Culture and found that millet only became a significant source of dietary protein approximately 1000 years later, as human carbon isotope values from these later sites indicated that almost all of dietary protein came from C₄ (i.e. millet) sources.     

Investigation of palaeodiet in the North Caucasus (South Russia) Bronze Age using stable isotope analysis and AMS dating of human and animal bones

This paper addresses the question of human palaeodietary adaptation in the Eneolithic and Early Bronze Age periods of the North Caucasus (South Russia) using stable isotope analysis. One of the key questions is the presence of fish in the diet. AMS radiocarbon dating of archaeological bone collagen has also been carried out to investigate potential radiocarbon reservoir effects in human skeletal material as a result of an aquatic diet. A fish component has previously been suggested in the diet of Iron Age and Bronze Age humans across Eurasia by isotopic research and radiocarbon dating of contemporaneous human and animal bones. In the North Caucasus however, isotopic data is scant. This study presents a new set of stable isotopic data from several Early Bronze Age sites, mainly belonging to the Maikop culture of the North Caucasus. The results show that the diversity in climate and environment across the northern Caucasus may be a causal factor for the patterns observed in the stable isotope values of terrestrial herbivores. This affects the isotopic values of the humans consuming them. The differences in δ¹⁵N and δ¹³C ranges of both humans and fauna were found to correlate strongly with geography and climate; the most enriched isotopic values are found in the dry steppe areas to the north. Overall, a relatively high enrichment in δ¹⁵N values of humans compared to local terrestrial herbivores and carnivores was observed. This indicates that aquatic resources were probably part of the Bronze Age diet in the region although the extent of this needs further investigation. The dramatic effect of environmental factors on isotopic values in the Early Bronze Age of the North Caucasus illustrates how confident conclusions cannot be drawn on the basis of a small number of samples from widely differing regions and time periods. Radiocarbon dating can provide a useful tool for identifying dietary derived reservoir ages in humans, potentially caused by a fish diet. With two possible exceptions, the nine human–animal bone pair dated as part of this study showed no consistent indication for a consistent reservoir effect.     

Assessing natural variation and the effects of charring,burial and pre-treatment on the stable carbon and nitrogen isotope values of archaeobotanical cereals and pulses

The aim of this study is to assess the potential of charred archaeobotanical cereal grain and pulse seed δ¹³C and δ¹⁵N values to provide evidence of crop growing conditions and as a potential component of palaeodietary studies. In order to reliably interpret archaeobotanical δ¹³C and δ¹⁵N values it is necessary to take into account the impact of charring, burial and laboratory pre-treatment procedures. We examine the effects of charring and burial on bulk δ¹³C, δ¹⁵N, %C, %N and C:N ratios in modern cereal and pulse material, and of cleaning by acid–base–acid (ABA) pre-treatment on modern and archaeobotanical charred material. Our study utilised bulk grain and seed samples to help account for within-ear/pod and between-plant variability in δ¹³C and δ¹⁵N values. Heating at relatively low temperatures and for prolonged times (230 °C for up to 24 h) is conducive to the formation of well preserved, undistorted charred cereal grain and pulse seed. Heating for 24 h has a systematic and predictable effect on δ¹⁵N values, with increases of around 1‰ on average in cereal grains and pulse seeds, and no consistent impact on δ¹³C values. Increases in δ¹⁵N are likely due to the loss of lighter ¹⁴N via N-containing volatiles. Burial (for up to 2 years) and ABA pre-treatment have no significant effects on δ¹³C or δ¹⁵N values. After pre-treatment, however, the %C and %N contents of the archaeobotanical material more closely resembles that of the modern charred grains and seeds, suggesting that archaeobotanical remains accumulate non-structural material during burial but retain their original carbon and nitrogen content. Therefore %C, %N contents and C:N ratios can provide useful criteria for assessing archaeobotanical preservation.     

Stable carbon and nitrogen isotope variations in tooth dentine serial sections from Wharram Percy

Here we report δ¹³C and δ¹⁵N measurements of serial sections of human deciduous and permanent tooth dentine from archaeological samples taken from the medieval village site of Wharram Percy, Yorkshire, UK. We found a pattern of enrichment, for both δ¹³C and δ¹⁵N, where the tooth crown was greater than the cervical part of the root, which in turn was greater than the apical portion of the root and the associated rib collagen values. This pattern reflects a decrease in the consumption of isotopically enriched breast milk and the introduction of less enriched weaning foods in the diet. The (mean±SD) difference between the deciduous second molar crowns and corresponding rib samples from the same individuals after 2 years of age was 1.2±0.4‰ for δ¹³C and 3.2±0.8‰ for δ¹⁵N. The δ¹⁵N values are as predicted, but as there were no C₄plants at Wharram Percy, this 1.2‰ enrichment in δ¹³C represents clear evidence of a carbon trophic level effect in collagen from breastfeeding infants. Carbon and nitrogen results also show that the infant diet among those who died in infancy did not differ from those who survived into childhood. This study demonstrates the promise of using dentine serial sections to study the temporal relationships of breastfeeding, weaning, and dietary patterns of single individuals.     

Inferences from the human skeletal material of the Early Iron Age cemetery at Agios Dimitrios,Fthiotis, Central Greece

The Geometric cemetery of Agios Dimitrios (850–740 B.C.) yielded a human osteological sample, with an MNI of 51 and equal numbers of males and females and adults and subadults. This site is of significant archaeological importance, as it provides information on human health status, diet, and activity patterns as well as mortuary behavior for a little studied time period. The results, including a) stable carbon and nitrogen isotopic data suggesting a C₃ low-protein plant diet, b) relatively high infant mortality, c) low stature estimates, d) significant prevalence of possible anemic conditions, and e) high dental infection and loss rates, all point to a rapidly increasing, stressed, and relatively malnourished population which did not exploit nearby marine resources, experienced suboptimal living conditions, and could not reach its biological potential. Furthermore, the study of this group provides evidence of equal burial treatment of all age and sex categories, no dietary differences in terms of sex and status, and no sex differentiation in pathological conditions.     

Stable isotope evidence for salt-marsh grazing in the Bronze Age Severn Estuary,UK: implications for palaeodietary analysis at coastal sites

Stable isotope analyses of modern coastal and salt-marsh plant species (‘salt-loving’ plants or halophytes) have demonstrated that these are significantly enriched in ¹⁵N compared to other terrestrial plants. Coastal salt-marshes were far more extensive in the past than they are today. They represented a vast and much-exploited resource in many areas of the UK and north-western Europe and were considered to be prime land for the grazing of animal stock.     

Stable isotope evidence of human diet at the Nukdo shell midden site,South Korea

Carbon and nitrogen stable isotope analysis was undertaken on bone collagen extracted from archaeological human (n = 48) and animal (n = 45) skeletons from the Nukdo site, Location I C, South Korea. This shell midden and grave site is dated from the late Mumun (550–300 BC) to early Iron Age (300 BC-1 AD) periods. The herbivorous mammals fell within the range of C₃ consumers, with average values of δ¹³C = −21.0 ± 0.5‰ and δ¹⁵N = 3.6 ± 0.5‰ for deer (n = 16) and δ¹³C = −20.6 ± 0.5‰ and δ¹⁵N = 4.5 ± 2.0‰ for wild boar (n = 17). Humans from this site averaged δ¹³C = −18.3 ± 0.4‰ and δ¹⁵N = 11.2 ± 0.7‰ for adults (n = 15) and δ¹³C = −18.7 ± 0.7‰ and δ¹⁵N = 12.5 ± 1.1‰ for juveniles (n = 33). These δ¹³C values indicate that there was no significant input of C₄ plants in the human diets and this may be associated with the spread of rice agriculture in the Mumun period. Human bone collagen δ¹³C and δ¹⁵N values indicate that there was some consumption of marine foods, although the main protein sources were from terrestrial foods. The isotope data demonstrate that the humans at Nukdo had mixed diets that included marine and terrestrial protein, including C₃ plants such as rice. Finally, the isotope results from the juveniles indicate that weaning occurred before the age of 1.5 years in this period.     

Mummies, maize, and manure: multi-tissue stable isotope analysis of late prehistoric human remains from the Ayacucho Valley, Perú

This paper reports the δ¹³C and δ¹⁵N values of bone collagen, muscle and skin from several late prehistoric–early colonial (AD 1490–1640) mummies from Perú's Ayacucho Valley. The mean of the δ¹³C and δ¹⁵N values of bone collagen are −11.5 ± 1.4 and 11.1 ± 0.7‰, respectively. The mean of the δ¹³C values for Vinchos skin is −11.8 ± 1.2‰ and the mean of δ¹⁵N values is 13.2 ± 0.5‰. The samples of muscle tissue have a δ¹³C mean of −11.9 ± 0.9‰ and a δ¹⁵N mean of 12.7 ± 0.3‰. The data from bone collagen indicate maize was the basis of the region's subsistence economy. A significant correlation between δ¹³C and δ¹⁵N values of bone collagen (R² = 0.75) is consistent with the preferential fertilization of maize with composted manure. Both skin and muscle samples are consistently enriched in δ¹⁵N relative to paired samples of bone (2.1 ± 0.5 and 1.6 ± 0.7‰, respectively), possibly as a result of short term physiological stress or differential decomposition.     

Stable carbon isotope analysis of human tooth enamel from the Bronze Age cemetery of Ya'amoun in Northern Jordan

Seventy-five teeth from the Bronze Age cemetery of Ya'amoun were sampled for carbon isotope analysis. The sampled teeth represented the transitional period of the Middle/Late Bronze Age. The results showed that the components of the diet that are reflected in the carbon isotope data remained the same during this period with an average δ¹³C of about −11.87‰. This value reflects more C₃ plant consumption.     

Stable carbon and nitrogen isotopes of human dental calculus: a potentially new non-destructive proxy for paleodietary analysis

Fifty-eight dental calculus samples from medieval and post-medieval skeletons from Vitoria, Spain, and a single sample from an Alaskan Inuit were tested for stable carbon and nitrogen isotope compositions. There was sufficient carbon and nitrogen concentrations to obtain δ¹³C and δ¹⁵N values, and the samples from Spain produced results that were replicable and comparable to European isotope values based on bone collagen collected from literature sources. The Alaskan Inuit calculus sample yielded a δ¹⁵N value of +17.5‰, well beyond the range of the Spanish samples, but consistent with literature data for modern Greenlandic Inuit consuming a diet rich in marine food. There are several potential sources for carbon and nitrogen in calculus. The results of this study yield stable isotope values consistent with those obtained from other biomaterials used as isotope proxies for paleodietary research, including bone collagen, hair, and fingernails, although further work is necessary to verify the fidelity of calculus as an isotope proxy. Many studies in bioarchaeology are precluded by curatorial concerns regarding the destructive analysis of primary biomaterials. However, calculus is an “add-on”, or secondary biomaterial, that is not an integral part of the dental or skeletal system. Hence, its consumption during analysis is technically not destructive. Therefore, isotope analysis of dental calculus may provide a potential new avenue for paleodietary analysis where the use of other primary biomaterials is precluded.     

Stable isotopic evidence for diet in a Roman and Late Roman population from Leptiminus,Tunisia

This study investigates the diet of the Roman and Late Roman population of Leptiminus on the Mediterranean coast of Tunisia. Stable carbon and nitrogen isotope analysis of human bone collagen and carbonate samples obtained from individuals buried in four cemeteries at Leptiminus was conducted in order to reconstruct the diet of the population, investigate the relative importance of marine vs. terrestrial resources, explore sex-, age-, and status-based variations in diet, examine temporal changes in the types of foods consumed, and compare the diet at Leptiminus with that of other Roman populations. The results of this study indicate that the residents of Leptiminus consumed a diet that was heavily reliant on terrestrial plant resources with the addition of a significant amount of marine resources. There were no significant sex differences in isotope values. In contrast, distinct dietary differences were seen between the adults and children. Nitrogen isotope values suggest that weaning began before the age of two and was completed by about 3 years of age, a finding consistent with previous isotopic studies of Roman samples. A temporal shift in diet is suggested by the nitrogen isotope values measured in samples from the most recent cemetery. A comparison of the data from Leptiminus with that derived from other Roman sites indicates that regional variability in diet existed within the Empire.     

Alkaline cooking and stable isotope tissue-diet spacing in swine: archaeological implications

In this study we examine the effects of alkaline cooking on carbon and oxygen stable isotopic ratios of mineralized tissues from nine pigs raised on monotonous mixed C3/C4 vegetarian diets. Two sources of collagen (humerus and mandible) and two sources of apatite (humerus and enamel) were analyzed. Within each diet group, humerus and mandible collagens were found to record equivalent δ¹³C and δ¹⁸O ratios; however, enamel apatite was found to be enriched over bone apatite by 2.3‰ in carbon and 1.7‰ in oxygen. Alkaline cooking was found to slightly, but significantly increase the Δ¹³C_{collagen-diet} and Δ¹⁸O_{collagen-diet} of bone collagen. A similar trend towards enrichment was observed in bone and enamel Δ¹³C_apatite-diet and Δ¹⁸O _apatite-diet, but the differences were not significant. Observed isotopic shifts were consistent with increased nutrient utilization of the alkaline-cooked maize as compared to raw maize. In addition, a reexamination of the relationship between diet and tissue carbon isotopic values suggests that species and alimentary type should be considered when interpreting ancient diets.     

Manuring and stable nitrogen isotope ratios in cereals and pulses: towards a new archaeobotanical approach to the inference of land use and dietary practices

This paper explores the impact of animal manure application on the δ¹⁵N values of a broad range of crops (cereals and pulses), under a range of manuring levels/regimes and at a series of locations extending from northwest Europe to the eastern Mediterranean. We included both agricultural field experiments and areas where ‘traditional’ farming is practised. Our aim is to ground-truth interpretation of δ¹⁵N values in archaeobotanical crop remains as evidence of past growing conditions and husbandry practices. The results confirm the potentially radical impact of manuring on δ¹⁵N values in cereals, depending on manuring level, but indicate only a slight effect on pulses, which can fix atmospheric nitrogen. The expected geographical trend towards greater δ¹⁵N with increasing climatic aridity is not apparent, probably because the growing conditions for crops are ‘buffered’ through crop management. Each of these observations has fundamental implications for archaeobotanical interpretation of δ¹⁵N values as evidence of land use practices and (together with analysis of bone collagen/tooth enamel in potential consumers) palaeodiet.     

Wild at heart: Approaching Pitted Ware identity,economy and cosmology through stable isotopes in skeletal material from the Neolithic site Korsnäs in Eastern Central Sweden

The Middle Neolithic Pitted Ware Culture on the Baltic Sea islands comprised a common identity distinguished, in part, by an almost exclusively marine diet. Based on evidence from the first stable isotope analysis on Pitted Ware skeletal material from the Eastern Central Swedish mainland, we suggest that this identity was shared by PWC groups in the archipelago of the west side of the Baltic. Fifty-six faunal and 26 human bone and dentine samples originating from the Pitted Ware site Korsnäs in Södermanland, Sweden were analysed, and the data clearly shows that the diet of the Korsnäs people was marine, predominantly based on seal. The isotope data further indicate that the pig bones found in large quantities on the site emanate from wild boar rather than domestic pigs. The large representation of pig on several Pitted Ware sites, which cannot be explained in terms of economy, is interpreted as the results of occasional hunting of and ritual feasting on wild boar, indicating that the animal held a prominent position, alongside seal, in the hunting identity and cosmology of the Pitted Ware people. Further, eleven new radiocarbon dates are presented, placing the Korsnäs site, with a large probability, within Middle Neolithic A.     

Stable isotopic evidence of diet in a Greek colonial population from the Black Sea

Archaeological and literary sources indicate that the ancient Greeks relied heavily on terrestrial resources and that their access to certain types of foods varied by sex and status. Human and faunal remains from the Greek colonial site of Apollonia (5th to 2nd century BC) on the Black Sea coast of Bulgaria were analyzed for stable carbon and nitrogen isotopes in order to reconstruct the diet of this population, investigate the relative importance of marine vs. terrestrial resources, and explore variations in diet with respect to age, sex, and burial type. The results of this study indicate that the colonists of Apollonia relied on a mixed diet of terrestrial and marine foods, and that there was little or no variation in diet by age, sex, or burial type. The relationship between δ¹³C and δ¹⁵N data for these samples suggests that while marine foods were an important source of nitrogen, much of the carbon used to construct amino acids came from terrestrial foods.     

Diet and mobility in Middle Archaic Florida: stable isotopic and faunal evidence from the Harris Creek archaeological site (8Vo24), Tick Island

We explore diet and mobility in Middle Archaic Florida using human burials and faunal remains from the Harris Creek archaeological site (8Vo24) on Tick Island. We conducted stable carbon and oxygen isotopic (δ¹³C, δ¹⁸O) analyses of 50 human enamel samples and strontium isotopic (⁸⁷Sr/⁸⁶Sr) analysis of a subset of 10. Most individuals (46/50) subsisted on local freshwater and terrestrial resources, with relatively depleted δ¹³C values (C₃) and δ¹⁸O values matching those of central and north Florida water resources within the St. Johns River valley. Eight of 10 burials have local, within valley ⁸⁷Sr/⁸⁶Sr values. Two human burials yield marine δ¹³C and ⁸⁷Sr/⁸⁶Sr values, which we interpret as evidence for across valley movement from the coast. Another two individuals show depleted δ¹⁸O values, likely obtained from northern rivers. We also identified potential food resources and non-local foods from the Harris Creek faunal assemblage. We found six species with estuarine and marine habitat preferences; two of which, whelk and quahog, indicate that people of Harris Creek traveled to or traded with coastal areas.     

Identification of pastoral sites using stable nitrogen and carbon isotopes from bulk sediment samples: a case study in modern and archaeological pastoral settlements in Kenya

The identification of pastoral sites in the East African archaeological record is problematic. Recently, a method for the identification of degraded livestock enclosure sediments had been developed that takes into account the geoarchaeological indicators of micromorphology, phytolith concentrations and the mineral assemblages. This suite of indicators may not always be present in degraded livestock enclosure sediments. This study presents an additional indicator by which degraded livestock enclosure sediments may be identified, namely the isotopic composition of organic nitrogen measured on bulk sediment samples. We studied a highly controlled ethnoarchaeological sequence of abandoned Maasai livestock enclosure sediments sampled in Rombo area, southern Kenya. The results were compared to archaeological sediments from the Elmenteitan Pastoral Neolithic site of Sugenya, southwestern Kenya, radiocarbon dated to ca. 2000 BP (uncalibrated). The sediments from both sites were studied using all four types of analyses, i.e., micromorphology, mineralogy, phytolith concentrations, and stable carbon and nitrogen isotopic compositions on bulk sediment samples. The results show that in abandoned livestock enclosure sediments of known ages a significant enrichment in the heavy nitrogen isotope (¹⁵N) occurs, and that carbon isotopic compositions may be useful for differentiating cattle from caprine enclosures following their dietary preferences (i.e., grazers vs. browsers). A similar pattern of ¹⁵N enrichment is observed in sediments sampled within the site of Sugenya while sediments sampled outside the site's perimeter are generally depleted in ¹⁵N. The micromorphological, mineralogical and phytolith analyses support the conclusion that the sediments from within the site of Sugenya represent degraded livestock enclosure sediments. The carbon isotopic composition from the degraded dung deposits strongly suggests that livestock kept at Sugenya were cattle. Overall, this study presents new empirical data that can be used for the identification of livestock enclosures, and shows that the isotopic signatures and geoarchaeological indicators can preserve for at least two millennia.     

Dietary patterns and social structures in medieval Sigtuna, Sweden, as reflected in stable isotope values in human skeletal remains

Stable isotopes (δ¹³C, δ¹⁵N) have been studied in human burials from the medieval town Sigtuna in Sweden. Dietary patterns of 80 adult individuals were analyzed on three cemeteries representing the phases of establishment, prosperity and decline of the town. All analyzed individuals were radiocarbon dated. One of the cemeteries, Church 1, represents a population of higher social status than those at the other two cemeteries.The δ¹³C values are homogenous and showed that the protein intake was mainly of terrestrial origin in the whole population. δ¹⁵N values varies more and they may indicate a higher input of vegetables in the diet at one of the cemeteries, the Nunnan block.Already in the initial phases of Sigtuna a social hierarchy had been established which is reflected in dietary patterns. Apparently more animal protein was consumed among the high status population of the town. Furthermore, differences in dietary patterns between the sexes were noted. In all phases the females show more clustered values indicating a more homogeneous diet than that of the males.