Ancient diet trick: Eating carbs to make your brain bigger

Humans really haven’t come that from from Neanderthals.

While consensus thinking says Neanderthals had a diet that consisted primarily of meat and some vegetables, our ice-age ancestors were also just like us: Neanderthals liked eating a ton of carbs — just like humans during the pandemic.

A new paper published in Proceedings of the National Academy of Sciences analyzed dead bacteria found inside the teeth of several Neanderthals dating back to 100,000 years ago. Researchers found that the bacteria present in the teeth specimens gave a clue into the diet habits of Neanderthals.

Through examining microbes, researchers said that the Neanderthal teeth showed that their diets consisted of plenty of nuts, roots, and other starchy foods that had an impact on the bacteria in their mouths.

“We investigate the evolutionary history of the African hominid oral microbiome by analyzing dental biofilms of humans and Neanderthals spanning the past 100,000 years and comparing them with those of chimpanzees, gorillas, and howler monkeys,” the researchers wrote in the study.

“We identify 10 core bacterial genera that have been maintained within the human lineage and play key biofilm structural roles. However, many remain understudied and unnamed. We find major taxonomic and functional differences between the oral microbiomes of Homo and chimpanzees but a high degree of similarity between Neanderthals and modern humans, including an apparent Homo-specific acquisition of starch digestion capability in oral streptococci, suggesting microbial coadaptation with host diet.”

Science Magazine described why the paper’s finding were so worthwhile because it could challenge what we’ve known about the diets of ancestors.

The study is “groundbreaking,” says Harvard University evolutionary biologist Rachel Carmody, who was not part of the research. The work suggests the ancestors of both humans and Neanderthals were cooking lots of starchy foods at least 600,000 years ago. And they had already adapted to eating more starchy plants long before the invention of agriculture 10,000 years ago, she says.

The brains of our ancestors doubled in size between 2 million and 700,000 years ago. Researchers have long credited better stone tools and cooperative hunting: As early humans got better at killing animals and processing meat, they ate a higher quality diet, which gave them more energy more rapidly to fuel the growth of their hungrier brains.

By consuming starchy foods, Neanderthals’ brains were able to develop due to the glucose found, according to the report.

Previous research has said Neanderthals had diets that primary consisted of meats and some vegetables. The Senckenberg Research Institute and Natural History Museum found that 80% of their diet consisted of meat, while 20% was vegetables.

Other studies have said that our extinct cousins had diets consisting of mainly seafood, with meat and pine nuts showing what has been deemed a “mixed diet.” Crabs, in particular, were common with Neanderthals that lived in Portugal between 106,000 and 86,000 years ago.