Relief food subsistence revealed by microparticle and proteomic analyses of dental calculus from victims of the Great Irish Famine

This study provides direct evidence of the dependency on relief food in Ireland around the time of the Great Famine (1845 to 1852) through dental calculus analysis of archaeological human remains. The findings show a dominance of corn (maize) and milk from the identified foodstuffs and corroborate the contemporaneous historical accounts of diet and subsistence. It shows that microparticle and proteomic analyses, even when based on small archaeological samples, can provide a valid snapshot of dietary patterns and food consumption. The occurrence of egg protein, generally only included in the diet for the better-off social classes, also highlights how these analytical techniques can provide unanticipated insights into the variability of diet in historical populations.Food and diet were class markers in 19th-century Ireland, which became evident as nearly 1 million people, primarily the poor and destitute, died as a consequence of the notorious Great Famine of 1845 to 1852. Famine took hold after a blight (Phytophthora infestans) destroyed virtually the only means of subsistence—}the potato crop{—}for a significant proportion of the population. This study seeks to elucidate the variability of diet in mid{–}19th-century Ireland through microparticle and proteomic analysis of human dental calculus samples (n = 42) from victims of the famine. The samples derive from remains of people who died between August 1847 and March 1851 while receiving poor relief as inmates in the union workhouse in the city of Kilkenny (52{°}39' N, -7{°}15' W). The results corroborate the historical accounts of food provisions before and during the famine, with evidence of corn (maize), potato, and cereal starch granules from the microparticle analysis and milk protein from the proteomic analysis. Unexpectedly, there is also evidence of egg protein{—}a food source generally reserved only for export and the better-off social classes{—which highlights the variability of the prefamine experience for those who died. Through historical contextualization, this study shows how the notoriously monotonous potato diet of the poor was opportunistically supplemented by other foodstuffs. While the Great Irish Famine was one of the worst subsistence crises in history, it was foremost a social disaster induced by the lack of access to food and not the lack of food availability