Imagining a Vegan U.S.: Good for Earth, Problematic for Humans

(Bloomberg) -- What would a vegan America look like? An herbivore population would enjoy a drop in greenhouse-gas emissions, but also face deficiencies in calcium, vitamins A and B12 and fatty acids.

That’s according to a new study by the U.S. Department of Agriculture and Virginia Tech University, which studied the possible impact of eliminating animals from the nation’s food production and putting citizens on a plant-based diet. 

The total American food supply would increase by 23 percent, as corn, soybeans and other crops fed to animals would be diverted to other uses, according to the study, published in the Proceedings of the National Academy of Science this month. Still, because land used to grow feed crops is often unsuited for fruits and vegetables, such farms would likely stay with grains, adding to a glut in commodities, the researchers said.

"We need to expand the way we think about food production to account for the complex consequences of changing any individual piece within the wider food system," Robin R. White, a professor at Virginia Tech who co-wrote the study, said in a statement Tuesday.

Vegan Cheerleaders

Vegan diets, whose proponents include former President Bill Clinton and talk-show host Ellen DeGeneres, eschew all animal products, differentiating themselves from vegetarians, who are primarily concerned with meat.

A complete shift from food-animal production would end meat, milk, egg, fish and cheese consumption, presenting nutritional challenges for many Americans, according to the study. A plant-only diet also would require individuals to consume more calories overall, as many foods used to replace animal-based products are less-dense in nutrients, the researchers said.

A move toward nationwide veganism would be planet-friendly, though, with its greenhouse-gas reduction. The loss of the livestock industry would more than offset the increased fertilizer and fossil-fuel use necessary in an exclusively plant-based system, the study said. Total U.S. emissions would fall by 2.6 percent as those for agriculture slump 28 percent.

The study didn’t offer any analysis of the personal impact of veganism, saying that individuals can take many paths toward a healthy, balanced diet.

"There’s a difference between what’s possible when feeding one person versus feeding everyone in the U.S.," Mary Beth Hall, a USDA researcher in Madison, Wisconsin, and a co-author of the study, said in the statement.

--With assistance from Megan Durisin

To contact the reporter on this story: Alan Bjerga in Washington at abjerga@bloomberg.net.

To contact the editors responsible for this story: Simon Casey at scasey4@bloomberg.net, Millie Munshi

©2017 Bloomberg L.P.