Early man ate carbs and processed food 780,000 years ago, northern Israel site shows
Analysis of basalt tools from the Hula Valley shows that Stone Age humans gathered, extracted and crushed starches from acorns, cereals, legumes and aquatic plants
Gavriel Fiske is a reporter at The Times of Israel
Prehistoric man did not follow the Paleo diet, a popular weight-loss plan that claims early hunter-gatherer societies subsisted largely on meat. Not only that, but a new Bar-Ilan University-led study released this week found that 780,000 years ago, early man enjoyed processed foods for the first time.
According to the study, carbohydrates and starch-rich foods from plants such as nuts, tubers and roots were a central component in the diet of prehistoric humans. Moreover, the study proves, they had the knowledge and technology to process them into edible form.
The scientists based their findings on an analysis of microscopic particles embedded in 780,000-year-old basalt stone tools found at a site along the Jordan River in northern Israel.
The research showed “for the first time starch remains… and this is how we can classify those tools as processing tools, perhaps specifically for plants,” explained Dr. Hadar Ahituv, lead author of the study, speaking to The Times of Israel by phone.
These tools – basalt “maces and anvils” – were used to crack open and crush plants and are “the earliest evidence of human processing of plant foods,” the university said in announcing the research. The tools were used on multiple plant species, “including acorns, cereals, legumes, and aquatic plants like the yellow water lily and now-extinct water chestnut,” the notice said.
The stone tools were found at Gesher Benot Ya’akov (The Daughters of Jacob Bridge), a site in the Hula Valley that once lay along the shores of the marsh-like Hula Lake, which was drained in the 1950s. The Gesher Benot Ya’akov site contains a wealth of remains from the early Stone Age Acheulean culture, including different kinds of stone tools, fossils of animal parts and various plant remains, including seeds and fruits.
Although previous studies had found edible plant remains at Gesher Benot Ya’akov the new research shows that the paleolithic peoples there had a specific technology for processing edible starchy plants, which required organized foraging, likely over long distances, and then extraction of the edible sections, which would then be mashed and perhaps treated with fire in a centralized location before consumption, Ahituv said.
The study, “Starch-rich plant foods 780,000 y ago: Evidence from Acheulian percussive stone tools,” was published this week in the peer-reviewed journal PNAS (Proceedings of the National Academy of Sciences of the United States of America).
Based mainly on Achituv’s doctoral thesis at Bar-Ilan, the research also “involved scholars from multiple institutions, including Prof. Nira Alperson-Afil and Dr. Yoel Melamed from Bar-Ilan University, Prof. Naama Goren-Inbar from the Hebrew University, and Prof. Amanda Henry from Leiden University, Netherlands,” the university noted.
The Stone Age societies at Gesher Benot Ya’akov knew their environment better than modern humans and had different technologies and practices for hunting and for the collection and processing of edible plants, Ahituv said.
“They knew their surroundings, they knew the plants that grew around them, they also knew the season and what they could collect,” he said.
They knew the edible parts of the plants such as “roots, bulbs, grains seeds or acorns… After they collected from different distances, they brought them to the site [where the tools were found].”
“We suggest it was a kind of sequence of processing for consuming the food. So it’s not just that you went out and collected the plants. You also needed to process them to be able to digest them better,” Ahituv said.
Probably, some of the starchy foods that were found on the crushing tools were later cooked in some way. Acorns in particular have bitter tannins that are removed by cooking, making them more digestible, and water chestnuts and water lily roots are inedible if they aren’t cooked, he said.
The basalt tools examined by the researchers were recovered from Gesher Benot Ya’akov in the 1980s in situ, not chemically treated or cleaned, and were then stored in a sterile environment, making the analysis of microscopic food starches particularly accurate, said Achituv, who currently manages the Laboratory for Ancient Food Processing Technologies (LAFPT) at the University of Haifa’s Zinman Institute of Archaeology.
Plant foods as a factor in human evolution
The study shores up the old adage that absence of evidence is not evidence of absence, according to the researchers.
“Despite their potential implications for hominin diet, cognition, and behavior, only rarely have plants been considered as drivers of human evolution, in part because they are less archaeologically visible… Our results further confirm the importance of plant foods in our evolutionary history and highlight the development of complex food-related behaviors,” the authors wrote in the study.
Stone Age humans certainly ate a variety of meat and fish, but modern thinking on ancient diets, exemplified by the Paleo diet trend that focuses on meat protein and foraged plants that are easy to consume, has been biased because hunting tools and animal remains are abundant in the archaeological record, Ahituv said.
Current technology and methodology, especially over the last 20 years, have given new avenues for researchers “to understand and reconstruct the past, including botanical remains,” so “we can say for sure that they didn’t only eat meat, but ate carbohydrates, maybe in high percentages,” he said.
For humans, plants are the main source of carbohydrates, which are essential for brain development and proper nutrition, so “it’s easy to understand” that paleolithic societies, which depended on using all available resources to survive and thrive, would develop methods of extracting and consuming them, Achituv said.
Hunting strategies have long been thought to have been the main force in the development of early human technologies and society. In the study, the authors argue that the consumption of plants played a role as well, as processing the starches showed the “advanced cognitive abilities of our early ancestors, including their ability to collect plants from varying distances and from a wide range of habitats and to mechanically process them using percussive tools.”
The new paper is unlikely to be the last word on the issue of ancient diets, a subject of debate in both academia and popular culture. A Tel Aviv University study from 2021 argued that early humans were efficient apex predators that only began consuming plant foods in significant amounts some 85,000 years ago, a date far later than the 780,000-year-old basalt tools analyzed by Achituv et al.
