A new study using isotope analysis suggests the idea of meat being the primary source of protein in all palaeolithic humans is no longer valid, as a North African population has been found to follow a mostly plant-based diet.

The researchers analysed the chemical signatures within bones and teeth of fossils from Iberomaurusians, a large Paleolithic group who lived between 30,000 and 11,000 years ago in today’s Morocco, Algeria, Tunisia, and Libya.

The study, titled “Isotopic evidence of high reliance on plant food among Later Stone Age hunter-gatherers at Taforalt, Morocco”, was published in the Nature Ecology & Evolution Journal by a team mostly from Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.

To look at meat consumption, the scientists focused on the nitrogen and zinc isotopes in teeth enamel and collagen, and to find out whether meat or fish was the primary source of protein they also looked at carbon isotopes.

Zineb Moubtahij, the lead author for the study, said to the Independent, “Our analysis showed that these hunter-gatherer groups, they included an important amount of plant matter, wild plants to their diet, which changed our understanding of the diet of pre-agricultural populations.” Klervia Jaouen, a co-author of the study, said that the “high proportion of plants in the diet of a pre-agricultural population” was “unusual”.

The scientists also found that the frequency of cavities in the buried remains in the Taforalt caves that Iberomaurusians used as burial sites suggested the consumption of “fermentable starchy plants” like beets, corn, rye, and cassava.

This is not the first evidence that debunks the myth of prehistoric humans being mostly meat eaters. A 2022 study on the role of carbohydrates in past hunter-gatherer diets in temperate Europe concluded that the carbohydrate and energy content of wild roots/rhizomes can be higher than in cultivated potatoes, showing that they could have provided a major carbohydrate and energy source for hunter-gatherers in Mesolithic Europe. This conclusion was supported by more recent studies that found remains of some of the 90 European plants with edible roots and tubers in a Mesolithic hunter-gatherer site on Harris, in the Western Isles of Scotland. Many of these plant foods would likely be underrepresented in archaeological excavations as they are fragile and difficult to preserve, which explains why early palaeontologists assumed meat-eating was dominant.

Jordi Casamitjana
“Originally from Catalonia, but resident in the UK for several decades, Jordi is a vegan zoologist and author, who has been involved in different aspects of animal protection for many years. In addition to scientific research, he has worked mostly as an undercover investigator, animal welfare consultant, and animal protection campaigner. He has been an ethical vegan since 2002, and in 2020 he secured the legal protection of all ethical vegans in Great Britain from discrimination in a landmark employment tribunal case that was discussed all over the world. He is also the author of the book, ‘Ethical Vegan: a personal and political journey to change the world’.