In a letter to the FDA, the Center for Science in the Public Interest in Washington says the agency should require additional tests, including a key animal study, before accepting rebiana as Generally Regarded as Safe, or GRAS.
A 26-page report by toxicologists at the University of California, Los Angeles, says that several, though not all, laboratory tests show the sweetener causes mutations and DNA damage, which raises the prospect that it causes cancer.
"A safe, natural, high-potency sweetener would be a welcome addition to the food supply," Michael F. Jacobson, executive director of the CSPI says in a statement. "But the FDA needs to be as sure as possible that rebiana is safe before allowing it into foods that would be consumed by tens of millions of people. It would be tragic if the sweetener turned out to cause cancer or other problems."
Coca-Cola and Pepsi plan to introduce new drinks made with rebiana, an extract of stevia leaves that is 200 times sweeter than sugar, Jacobson said.