Diets Were Almost Exclusively Vegetarian in the First European Cities

Prehistoric humans living in Europe's earliest large settlements followed a diet that was almost exclusively vegetarian, a study has found.

In the study, published in the journal PNAS, a team of researchers investigated the agricultural and economic system of ancient "mega-sites," which were built around 6,000 years ago by the Trypillia culture in what is now Ukraine and Moldova in Eastern Europe.

These early European cities covered up to 320 hectares (791 acres) and housed as many as around 15,000 inhabitants. At the time, the mega-sites were the largest settlements in the world, according to the study.

Each of the mega-sites existed for multiple generations. But to date, the economy of the Trypillia settlements has remained poorly understood, particularly when it comes to how exactly the mega-sites' inhabitants sustained themselves with food.

Those inhabitants were largely farmers who grew crops and raised livestock. But how could such large groups of people have secured their food supply with the technology available at the time?

The latest study has shed new light on this issue, finding that the mega-sites survived thanks to an "extremely sophisticated food and pasture management" system, Frank Schlütz, a paleoecologist at Germany's Kiel University and one of the authors of the study, said in a press release.

The team came to these conclusions after analyzing nitrogen and carbon isotopes in human remains, animal bones and charred crops found at Trypillia settlements, which enabled them to shed light on their ancient food webs. Isotopes are atoms of the same element that have the same number of protons but a different number of neutrons.

The analysis allowed the scientists to predict how domestic animals were kept, whether the cultivated crops were fertilized and what role plants and animals played in the diet of the time.

"The measuring of isotopes was done in specialized laboratories on charred cereal grains and peas—in the soil only charred plant material is durable—and on collagen extracted from human and animal bones," Schlütz told Newsweek.

"With every step in the food chain, the isotope values increase to a known extent," he said. "As herbivores are one level above plants, both groups are different in isotope composition, with animals having the higher values. As cereals and legumes are quite different plant groups, they differ in isotopes from each other as well. Thanks to this, it is possible to calculate the relative amounts of food sources—meat, grains, peas—consumed by the humans."

The team's results suggest that the diet of the people living in the Trypillia mega-sites was predominantly vegetarian, based mostly on cereals and pulses, particularly peas. The team's findings indicate that animal products were only a small proportion, around 10 percent, of calorie intake.

Nevertheless, as an essential ingredient of feasting, meat may have played a central role in social cohesion and stability, according to the researchers.

The team also concluded that grazing animals, such as cattle and sheep, were kept on fenced pastures, producing manure that was used to intensively fertilize the pulses, thus ensuring sufficient yields. In addition, the pea straw, an agricultural byproduct, was used to feed the livestock on the pastures.

"[The study] is the earliest scientific evidence I know of for such high-protein consumption from peas/legumes," Schlütz said. "And at the same time the earliest evidence of very intensive manuring of legumes. The intensive manuring was probably necessary to achieve large harvests on a small area. By this, the main task of the animals was to produce manure for fertilization."

The study's authors wrote: "The flourishing of Europe's first mega-populations depended on an advanced, integral mega-economy that included sophisticated dung management."

The findings also shed new light on the demise of these early cities, whose heyday lasted for around 500 years. By around 3000 B.C., the Trypillia societies had disappeared. The authors suggest that there was "no discernible economic reason" for the demise of the mega-sites, given their sophisticated food system. Rather their downfall was more likely to have been caused by sociopolitical inequalities.

"As we know from previous studies, social tensions arose as a result of increasing social inequality. People turned their backs on large settlements and decided to live in smaller settlements again," archaeologist Robert Hofmann, another author of the study who is at Kiel University, said in the press release.

Update 1/5/24, 10:57 a.m. ET: This story was updated with comments from Frank Schlütz of Germany's Kiel University