Twenty-nine thousand years ago, in what is now the Czech Republic, someone may have swallowed a lake-dwelling midge without realizing it. Thousands of years later, in Germany, another person may have eaten food infested with insects. In the teeth of ancient Europeans, insects look less like food than accidental evidence.
Today, edible insects are often promoted as a sustainable protein source, but Western consumers remain hard to convince. A new study published in Science Advances points to a reason that may reach further back than taste or culture.
By analyzing ancient dental plaque from anatomically modern humans, Neanderthals, and great apes, the researchers found that ancient Europeans consumed insects only rarely and likely by accident, with far less insect DNA in their teeth than in those of Neanderthals or several insect-eating great apes. European populations have also carried genetic variants linked to reduced chitin digestion, a tough material found in insect exoskeletons, for at least 9,000 years, a pattern that may predate many later cultural and religious explanations for the aversion.
“The scarce presence of insects in the diet of northern Eurasians suggests that the absence of entomophagy is not solely due to recent cultural factors, but also to a long ecological and evolutionary history,” said lead author Pablo Librado in a press release.
Bugs Show Up in Ancient Teeth, but Barely as Food
Dental plaque is one of the more intimate archives the human body keeps. As it hardens, it can trap DNA from food, water, and the surrounding environment. For this study, the team analyzed plaque from 745 anatomically modern humans, 18 Neanderthals, and 96 great apes.
In ancient European samples, insect DNA appeared only in small amounts, closer to what the researchers found in rainforest chimpanzees, which eat very few insects, than in western chimpanzees or gorillas.
Neanderthal dental plaque contained more insect DNA, at levels comparable to western chimpanzees, which use insects to supplement their diet. Many traces belonged to flies and mosquitoes, a pattern the authors say may fit with the idea that Neanderthals sometimes consumed animal carcasses infested with fly larvae.
Read More: 100,000-Year-Old Neanderthal Teeth May Reveal How Early Humans Moved Across Europe
The Enzyme Clue Behind Insect Eating
The second line of evidence came from genes involved in chitin digestion. Two genes in particular, known as CHIA and CTBS, help produce stomach enzymes that break down chitin.
In populations closer to the tropics, where insects are more available year-round, the researchers found variants linked to stronger chitin digestion. In European and northern populations, those variants were much less common. The pattern has remained in place for at least 9,000 years, through agriculture, migration, and major cultural change.
Neanderthals showed the opposite pattern, carrying variants associated with enhanced chitin digestion, matching the higher insect DNA found in their plaque.
Why the West Still Struggles With Eating Bugs
As the global population grows and livestock farming strains land, water, and the climate, edible insects are often presented as a practical alternative. They are already part of regular diets for hundreds of millions of people.
The new findings do not mean people of European descent cannot eat insects. Modern processing can remove or reduce chitin from insect products, potentially helping sidestep the digestive barrier. But for those who recoil at the idea, the reaction may not be simple squeamishness or a modern cultural quirk.
It may echo a much older pattern, one in which insects rarely entered the diet on purpose and, over time, European populations became less equipped to digest one of their defining materials.
Read More: Ancient Tooth Proteins Reveal Possible Link Between Homo erectus, Denisovans, and Modern Humans
Article Sources
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- This article references information from a study published in Science Advances: Genomic evidence for limited entomophagy in ancient Europeans
