New research reveals long-term changes in human nutrition

Oct 5, 2021

Corn is one of the primary sources of calories for modern Americans.

Dr. Stefani Crabtree, a professor at USU, studies humans in the context of our archaeological past. Her latest research used isotope analysis of hair and fingernail samples to compare the nutrition of modern humans with the nutrition of our ancestors. 

As a species, humans are evolved to be omnivorous. This flexibility allows us to extract a variety of foods from our environments.

"And what this does is it makes people more resilient to environmental fluctuations. So if your favorite kind of food is not available, you can choose to eat something else," Crabtree said.

According to Dr. Crabtree’s findings, most modern humans have a narrower diet than our ancestors. Dietary breadth is reflected by a range of isotope values, and this range is compressed in modern urban humans. Increased reliance on agriculture has resulted in a food system that depends heavily on certain food groups.

"If we ended up having a corn blight, like there was the potato blight that led to the Irish potato famine, that would be absolutely disastrous to our food system, because we use corn to feed almost everything," said Crabtree.

Dr. Carrie Durward, a Nutrition Specialist with USU Extension, said that most of the calories Americans are eating come from corn, wheat, sugar and rice. Purchasing produce directly from farmers supports a local food web, which will be more specialized and have more variety.

"It makes our food webs more resilient to climate change, drought, big storms, or epidemics that might disrupt food supply chains, nationally and globally. And so by supporting those local sources of food, we are supporting variety and sustainability of our diets," said Durward.