A new study led by Dr Łukasz Pospieszny, Marie Curie Research Fellow at the Department of Anthropology and Archaeology, providing isotopic evidence for earliest consumption of broomcorn millet in East-Central Europe, has just been published in the Journal of Archaeological Science. It brings together 24 researchers from Poland, Ukraine and Great Britain, including Dr Jamie Lewis from the School of Earth Sciences.

Broomcorn millet is one of the few plant species cultivated in the prehistory that were not domesticated in the New East. It was first cultivated in China and for years there have been controversies about when was it brought to Europe. The results of direct dating of more than 150 finds of charred millet grains, published in 2020, indicated its appearance in east and central part of the continent in the mid-15th century BC.

However, to this day it was not fully known when it was first consumed there and who were the first ‘millet-eaters’. As millet has a different photosynthetic pathway than all other domesticated plants of the Bronze Age, it exhibits clearly elevated values of stable carbon isotopes in its tissues. This isotopic biomarker is passed on in the food chain and can be used for tracing its consumption by animals and humans.

Stable isotope analyses of both carbon and nitrogen in bone collagen were conducted for 122 individuals from 37 archaeological sites in Poland and western Ukraine. All studied skeletons were also radiocarbon dated and the mean absolute ages of 120 of them range within only 1000 years, from ca. 2200 to 1200 BC. Such a relatively high temporal resolution made it possible to indicate with unprecedented precision when millet began to be eaten and to track temporal changes of its contribution to human diets.

It is now clear that in the areas of today's Poland and western Ukraine, millet became a permanent item on the menu in the Middle Bronze Age, soon after it first shows up in archaeological record as charred grains. The earliest ‘millet–eaters’ were found in a communal grave at Pielgrzymowice in Lesser Poland and under a burial mound at Kordyshiv in Podolia.

Their remains come from the second half of the 15th century BC. The share of millet in the diet of these people, however, was not higher than approx. 20%. Its popularity peaked in the 12th century BC, when it could account for up to half of the diet, which also included other cereals, primarily wheat, and animal products: meat and dairy. In three cases, it was also possible to unravel changes in the share of millet in the diet of subsequent generations, living over a period of several dozen to several hundred years, but buried in one communal grave.

This study was a part of a project led by Professor Przemysław Makarowicz and hosted by the Faculty of Archaeology at the Adam Mickiewicz University in Poznań, Poland.