Diet in medieval Lithuania: Stable carbon and nitrogen isotopic analysis of bone and dentin collagen from the site of Alytus Katie M Whitmore 1 , Tosha Dupras 1 , Lana Williams 1 , Rimantas Jankauskas 2 , John Schultz 1 1 Department of Anthropology, College of Sciences, University of Central Florida 2 Department of Anatomy, Histology and Anthropology, Faculty of Medicine, University of Vilnius OBJECTIVE Here we present a preliminary assessment of diet at late medieval Alytus (late 14 th to early 18 th centuries) through analysis of stable carbon and nitrogen isotopic data from bone (N=35) and dentin (N=38) collagen samples. Little stable isotope analysis has been undertaken in this region during the medieval period. Research Questions • What was the diet like for the average individual at medieval Alytus? • Are there dietary differences between males and females at medieval Alytus? BACKGROUND Medieval Europe underwent a number of social and cultural changes including those related to disease, agriculture, and religion. The Black Death and resultant decrease in population size (some estimates approximate around one third of Europe’s population died) meant there were relatively more resources available to those that survived. Regardless of social status individuals had access to better and higher quality foods 1, 2 . Some fields were converted to graze livestock, as a decreased population size left agricultural fields unplanted 1 . Meat, usually considered a luxury item, as well as dairy products such as milk, cheese, and butter became more available. Fish and other aquatic resources became increasingly important during the medieval period due to food prohibitions associated with Catholic fasting customs, which were practiced for approximately one third of the year 1 . Medieval Alytus, Lithuania The Alytus cemetery is located approximately 500 meters from the Alytus hill-fort along the Nemunas River. The Alytus hill-fort was established around 1365 in response to ongoing conflicts with Teutonic Knights 3 . Despite the militaristic purpose of the hill-fort, Alytus was a rural town where the majority of its citizens were employed in agrarian occupations such as agriculture, hunting, fishing, and animal husbandry 3 . It is estimated that approximately 50% of the Alytus population worked in agriculture 4 . Agrarian staples of the Lithuanian economy included grain, hides, honey, flax, and cheese 5 . Gardens and fields during this time would have included cabbages, turnips, onions, beets, parsnips, wheat, barley, rye, flax, and buckwheat 6, 7 . The Conversion of Lithuania took place in 1387 only a few decades after the establishment of the Alytus hill-fort. However, Lithuania was the last pagan country in Europe, and the adoption of Catholicism is considered to be one of the most complicated processes of Christianization in history 8 . MATERIALS AND METHODS Thirty-five femoral bone samples and 38 dentin samples (first molars, maxillary and mandibular) make up the total sample. Thirty-four individuals are represented by both bone and dentin samples. A total of 39 different individuals are investigated in the study. Bone collagen reflects the diet during approximately the last decade of life, whereas dentin collagen reflects diet during childhood from approximately birth to seven years. Extraction of bone collagen followed a modified version of the Longin (1971) 9 method and extraction of dentin collagen followed a modified version of the method presented in Wright and Schwarcz (1999) 10 . RESULTS The mean δ 13 C value for bone collagen is -20.08‰ and range from -20.59‰ to -19.54‰ with a standard deviation of +/-0.26‰ and a standard error of 0.04‰. The mean δ 15 N value for bone collagen is 10.29‰ and range from 8.69 to 12.15‰ with a standard deviation of +/-0.91‰ and a standard error of 0.15‰. There are no significant differences in bone collagen δ 13 C values (p=0.139) or in δ 15 N values (p=0.149) between males and females (Fig. 1). The mean δ 13 C value for dentin collagen is -20.11‰ and range from -20.80‰ to -19.45‰ with a standard deviation of +/-0.30‰ and a standard error of 0.05‰. The mean δ 15 N value for dentin collagen is 10.66‰ and range from 9.08‰ to 12.43‰ with a standard deviation of +/-0.91‰ and a standard error of 0.15‰. There are no significant differences in dentin collagen δ 13 C values (p=0.343) or in δ 15 N values (p=0.374) between males and females (Fig.2). There are no significant differences in δ 13 C values (p=0.310) between dentin and bone collagen. There is a significant difference in δ 15 N values (p=0.043) between dentin and bone collagen. DISCUSSION AND CONCLUSION Overall the δ 13 C values for the Alytus bone and dentin collagen samples indicate individuals were almost exclusively consuming primarily C 3 plants, most likely wheat and barley, and C 3 fed animals during both the adult and juvenile periods, and possibly consuming small amounts of aquatic protein resources. Overall the δ 15 N values for the Alytus bone collagen samples with a mean of 10.29‰ indicate that individuals were almost exclusively consuming terrestrial fauna, such as cow, deer, pig and sheep during the adult and juvenile periods. The mean and range of δ 15 N values for the Alytus adults may also indicate the consumption of freshwater resources. The δ 13 C and δ 15 N values do not indicate difference in the diet between adult males and adult females or between juvenile males and juvenile females suggesting that both sexes had access to similar types of food resources. These stable isotopic data are consistent with historical accounts of medieval Lithuanian agrarian resources. There is a significant difference between the overall bone and dentin δ 15 N values, upon closer examination this appears to be a result of the difference between male dentin and female bone collagen δ 15 N values (p=0.025). There are several possible explanations for the depleted female δ 15 N bone collagen values and the enriched male δ 15 N dentin collagen values. Juveniles at Alytus exclusively breastfeed through two years of age, were weaned from two to four years of age, and by five years of age no longer have evidence of breastfeeding (Page, personal communication). Male juveniles may have incorporated more terrestrial or aquatic protein resources, or perhaps male juveniles were weaned later than female juveniles. Historical medieval European medical documents recommended the cessation of breastfeeding later for males than females 16 . Another possibility is adult females were consuming less terrestrial or aquatic protein resources. However, the lack of difference between adult males and adult females and between juvenile males and juvenile females indicates that the difference in δ 15 N values between bone and dentin collagen is a result of a combination of factors. The Alytus bone collagen data was compared to five medieval sites in Europe, the Gilbertine Priory, England 11 , Koksigde in Belgium 12 , Sagalassos, Turkey 13 , Ribe in Denmark 14 , and females from Giecz, Poland 15 (Fig. 3). While it is clear that the individuals at Alytus have depleted δ 13 C values compared to the other five sites, the δ 15 N for Alytus individuals is most similar to the site of Koksigde where individuals were incorporating marine protein into a diet largely based on terrestrial foods 12 . Freshwater marine resources have a large variability in δ 13 C values and without additional faunal data from Alytus it is not possible interpret further on the importance of aquatic resources in the medieval Alytus diet. Overall, the individuals at Alytus were consuming a fairly homogenized diet of C 3 terrestrial plant and faunal resources and probably incorporating some aquatic resources. Figure 1. δ 13 C and δ 15 N values for males and females in the bone collagen sample. Red line indicates the linear relationship for males and the blue line indicates the linear relationship for females. Figure 2. δ 13 C and δ 15 N values for males and females in the dentin collagen sample. Red line indicates the linear relationship for males and the blue line indicates the linear relationship for females. Figure 3. Comparison of the Alytus mean overall, female, and male δ 13 C and δ 15 N bone collagen values to five European archaeological sites 11, 12, 13, 14, 15 . 1 Adamson MW. 2004. Food in medieval times. Westport: Greenwood. 2 Stone D. 2006. The consumption of field crops. In: Woolgar C, D Serjeantson, T Waldron, editors. Food in Medieval England. Oxford: Oxford University Press. p 11-26. 3 Kozakaite J. 2011. The analysis of long bone fractures and dislocations in 14 th – 17 th century Alytus, Lithuania. MSc thesis, Department of Archaeology, Durham University, England. 4 Faerman M, Jankauskas R, Gorski A, Bercovier H, Greenblatt CL. 1997. Prevalence of human tuberculosis in a medieval population of Lithuania studied by ancient DNA analysis. Anc Biomolecules 1:Dec. 5 Fletcher R. 1997. The barbarian conversion: From Paganism to Christianity. New York: Henry Holt and Company. 6 French RA. 1970. The three-field system of sixteenth-century Lithuania. The Agricultural History Review 18(2):106-125. 7 Stančikaitė M, Kisielienė D, Mažeika J, Blaževičius P. 2008. Environmental conditions and human interference during the 6 th and 13 th -15 th centuries A.D. at Vilnius Lower Castle, east Lithuania. Veget Hist Archaeobot 17:S239-S250. 8 Rowell SC. 1994. Lithuania ascending: a pagan empire within east-central Europe, 1295-1345. Cambridge: Cambridge University Press. 9 Longin R. 1971. New method of collagen extraction for radiocarbon dating. Nature 230:241-242. 10 Wright LE and Schwarcz HP. 1999. Correspondence between stable carbon, oxygen and nitrogen isotopes in human tooth enamel and dentine: infant diets at Kaminaljuyu. J Archaeol Sci 26:1159-1170. 11 Mϋldner G, Montgomery J, Cook G, Ellam R, Gledhill A, Lowe C. 2009. Isotopes and individuals: diet and mobility among the medieval Bishops of Whithorn. Antiquity 83:1119-1133. 12 Polet C and Katzenberg MA. 2003. Reconstruction of the diet in a mediaeval monastic community from the coast of Belgium. J Archaeol Sci 30:525-533. 13 Fuller BT, De Cupere B, Marinova E, Van Neer W. 2012. Isotopic reconstruction of human diet and animal husbandry practices during the Classical-Hellenistic, Imperial, and Byzantine Periods at Sagalassos, Turkey. Am J Phys Anthropol 149:157-171. 14 Yoder C. 2010. Diet in medieval Denmark: a regional and temporal comparison. J Archaeol Sci 37:2224-2236. 15 Reitsema LJ, Crews DE, Polcyn M. 2010. Preliminary evidence for medieval Polish diet from carbon and nitrogen stable isotopes. J Archaeol Sci 37:1413-1423. 16 Mays SA, Richards MP, Fuller BT. 2002. Bone stable isotope evidence for infant feeding in Mediaeval England. Antiquity 76:654-656.