Washington, D.C. – That burger you ordered comes with more than beef, lettuce and tomato. There’s a bit of corn and nitrogen, too.
University of Hawaii scientists tested fast-food items across the country and found evidence of both the corn used for the animals’ feed and the nitrogen used as fertilizer to grow the corn and emitted in the animals’ manure.
Nearly all the beef in the burgers and all of the chicken tested contained levels of a carbon isotope that proves the animal the meat came from was fed corn.
A nitrogen isotope that was found in the meat comes from the fertilizer and also is evidence that the animals were raised in confined conditions, the scientists said. Nitrogen is in the ammonia emitted in animals’ manure.
The scientists also detected corn in some of the french fries they tested, evidence that the potatoes were fried in corn oil.
“If you put any money into fast food, it all goes back to corn, everything. The first step to making hamburgers is making an ear of corn,” said Hope Jahren, lead author of the study, which was released Monday by the Proceedings of the National Academy of Sciences.
The scientists said consumers deserve to know about the source of their food, given the environmental concerns of growing corn, which requires large amounts of fertilizer that can run off fields and pollute rivers and streams.