Ancient History

Highlights

• Carbonate δ13C was measured in tooth enamel and bone of Ancient Egyptians.

• δ13C remains largely constant from 5500 to 2000 BP and indicates very low C4-intake.

• High δ15N of mummy hair is indicative of aridity and not of trophic level.

• δ13C of hair indicates <50% of dietary protein came from animals.

• Sulfur isotopes suggest that fish, such as the Nile Perch, was not regularly consumed.

Abstract

Carbon, nitrogen and sulfur stable isotope compositions were measured in hard and soft tissues from Egyptian mummies of humans and animals in order to track the diet of ancient Egyptians from 5500 to 1500 years B.P. The carbon isotope ratios of bone apatite (δ13Cbo = −14.3 ± 0.9‰) and hair protein (δ13Ch = −19.9‰) are compatible with a diet based almost exclusively on C3-derived food (proportion of C4 < 10%). Less negative carbon isotope ratios of enamel (δ13Cen = −11.6 ± 0.7‰) relative to bones from the same mummies could be the result of differences in the chemical microenvironment in which mineralization occurred, as well as of differences in diet between children and adults, in particular through the consumption of milk or millet gruel during infancy and childhood. High values of nitrogen isotope ratios for hair protein (δ15Nh = 9.1‰–15.5‰) are ascribed to aridity rather than fish consumption because the δ34S values of human hair are lower than those measured in Nile perch scales. Except for Coptic mummies, the constancy of δ13Cbo and δ13Cen over a duration of ∼3000 years is striking considering the various political, technological, and cultural changes that impacted the Egyptian civilization during this time interval.

Carbon isotope ratios were measured in enamel, bone, and hair of ancient Egyptians.

 A significant offset (+2.5‰) is observed between the 13C values of teeth and bones that

 cannot be ascribed to the weaning effect. Following Warinner and Tuross (2009), this isotopic

offset rather may be caused by differences in mineralization conditions of the two types of

tissue. Using tissue-specific equations, the 13C value of the reconstructed diet is comparable and close to the average value of C3-plants (-25‰). 13C values of hair from ancient

with previous studies (Iacumin et al., 1996; Thompson et al., 2005).

Egyptians also suggest that C4-derived foods were rare in the diet (<10%), a result consistent

proportion of protein of animal origin may have reached 50%. Both estimates are lower than
Sulfur isotope ratios of mummy hairs further indicate that freshwater fish, such as the Nile

Carbon isotope ratios in mineralized tissues are constant throughout the studied period, indicating a preference for C3-derived food throughout the investigated time span. This is a surprising result given that C4 plants are better suited to arid environments, and that the climate became increasingly arid during this period (Touzeau et al., 2013). Coptic mummies have 13C values slightly lower than other mummies, possibly as a result of the introduction of olive oil during the Roman Period.

Assessing the consumption of animal products is difficult because the 15N of soft tissues, such as hair, is controlled by parameters other than diet, and in particular by the prevailing hydric stress. Using the carbon isotope ratios of mummy hairs, the contribution of animal protein to the total dietary protein was estimated here at 29±19%, corresponding to an ovo-lacto-vegetarian diet. Taking into account potential biases in the diet reconstruction, the

the average value of 64% characterizing modern omnivorous Europeans (Petzke et al., 2005).

perch, was not consumed in significant proportions.