An analysis of fossilized Native American feces shows that our ancestors ate up to sixteen times the fiber that we do today, but our stomachs didn’t evolve to fit our changing diets.
The findings come from analysis of fossilized feces dating from A.D 1123 and earlier. They reveal that the ancient Native Americans lived on a heavily fibrous diet of prickly pear, yucca, and seeds, with low impact on blood sugar.
The native people of Arizona ate foods with traditionally very low glycemic indexes, but are now more susceptible to type 2 diabetes than Caucasians, for their bodies do not produce enough insulin to break down the sugar in modern foods. The Native populations were extremely efficient in their calorie intake, but the arrival of Europeans caused their diet to change faster than their bodies could keep up with, and their digestive systems didn’t evolve to handle foods with a high glycemic index.
Modern humans of all ethnicities have suffered from this dietary change.
Modern agriculture favors plants with less fiber than what our ancestors ate, and it is nearly impossible to reach the same fiber intake levels of ancient populations. “It’s kind of like going from chewing on pumpkin seeds to chewing on oatmeal” says Karl Reinhard, professor of forensic sciences at the University of Nebraska-Lincoln.
The diet found in the fossils of Southwestern America is likely similar to what people ate the whole world over before humans invented agriculture and cultivation of wheat, millet, rice, and other grains.
“When I was a young researcher, I tried to replicate this diet, and it was impossible. I was essentially eating all day to try to get this fiber,” said Reinhard.
While our diets have changed to favor calorie intake, our stomachs remain built to handle an abundance of fiber. This sheds light on why some populations are more prone to diabetes in modern times than others and why there has been an epidemic in diabetes for modern populations.