() President Donald Trump’s claim that Coca-Cola is switching to cane sugar has left a bitter taste for corn syrup lobbyists, who warn that the recipe shake-up will threaten the income of thousands of American farmers.

The Corn Refiners Association, which represents high-fructose corn syrup producers, said the change threatens thousands of jobs and risks devastating primarily Midwest American farms.

“There are about 10,000 people working in corn refining. One-third of the corn refined goes for making high-fructose corn syrup,” said John Bode, president and CEO of the Corn Refiners Association. “If we eliminate high-fructose corn syrup use, that’s going to have a very substantial effect on at least a third of the production, probably significantly more of the corn refining industry. So that’s thousands of jobs.”

Despite Trump’s announcement Wednesday, Coca-Cola has yet to confirm the change.

The announcement has reignited a decades-long food fight between the two sweeteners, with share prices for some major corn syrup companies experiencing dramatic drops Thursday.

According to the American Medical Association, there are no known nutritional differences between high-fructose corn syrup and cane sugar, but neither should be consumed in large quantities.