Turns Out Developing A Taste For Carbs Wasn’t A Bad Thing, Harvard University Gazette, 10 May 2021
The Evolution And Changing Ecology Of The African Hominid Oral Microbiome, Proceedings of the National Academy of Sciences, 18 May 2021
A new study looking at the evolutionary history of the human oral microbiome shows that Neanderthals and ancient humans adapted to eating starch-rich foods as far back as 100,000 years ago, which is much earlier than previously thought.
The findings suggest such foods became important in the human diet well before the introduction of farming and even before the evolution of modern humans. And while these early humans probably didn’t realize it, the benefits of bringing the foods into their diet likely helped pave the way for the expansion of the human brain because of the glucose in starch, which is the brain’s main fuel source.
“We think we’re seeing evidence of a really ancient behavior that might have been part of encephalization — or the growth of the human brain,” said Harvard Professor Christina Warinner, Ph.D. ’10. “It’s evidence of a new food source that early humans were able to tap into in the form of roots, starchy vegetables, and seeds.”
The biggest surprise from the study was the presence of particular strains of oral bacteria that are specially adapted to break down starch. These strains, which are members of the genus Streptococcus, have a unique ability to capture starch-digesting enzymes from human saliva, which they then use to feed themselves. The genetic machinery the bacteria uses to do this is only active when starch is part of the regular diet.
Both the Neanderthals and the ancient humans that scientists studied had these starch-adapted strains in their dental plaque while most of the primates, who feast almost exclusively on non-starchy plant parts, like fruits, stems, and leaves, had almost no streptococci that could break down starch.
The findings also push back on the idea that Neanderthals were top carnivores, given that the “brain requires glucose as a nutrient source and meat alone is not a sufficient source,” Warinner said.
Richard W. Wrangham, Ruth B. Moore Professor of Biological Anthropology and one of the paper’s co-authors: “These new data make every sense to me, reinforcing the newer view about Neanderthals that their diets were more sapiens-like than once thought, [meaning] starch-rich and cooked.”
Paleo Diet followers attempt to adhere to a diet our ancestors ate, thus “Paleo.” Do you think they will welcome this discovery?