FDA Fails to Demand Needed Tests, Its Approval Not Based on “Convincing Evidence” as Required by Law

Yesterday, Center for Food Safety (CFS) filed a legal brief in its challenge to the U.S. Food and Drug Administration’s (FDA) 2019 approval of soy leghemoglobin (“heme”), a color additive used to make Impossible Foods’ eponymous plant-based burger, the Impossible Burger, appear to “bleed” like real meat.

The novel heme colorant is produced in genetically engineered (GE) yeast, and is modeled on a protein found in the roots of soybean. The GE heme is actually a color additive preparation that also contains over a dozen yeast proteins. Because GE heme is new to the human diet, and substantial quantities are added to the Impossible Burger, FDA should have required extensive safety testing before approving its use as a color additive, as required by law.

“FDA approved soy leghemoglobin even though it conducted none of the long-term animal studies that are needed to determine whether or not it harms human health,” said Bill Freese, science policy analyst at Center for Food Safety. “This includes studies for cancer, reproductive impairment, and other adverse effects called for by FDA’s Redbook, the Bible of food and color additive testing,” he added. “We find this to be all the more troubling because a number of potential adverse effects were detected in a short-term rat trial: disruption of reproductive cycles and reduced uterine weights in females, and biomarkers of anemia, reduced clotting ability, and kidney problems.”

The law on color additives is clear: Because they offer no substantive benefits, and add only aesthetic appeal, Congress and FDA established an extremely high bar for approval. The agency’s “convincing evidence” standard means that a color additive cannot be approved without the strongest possible evidence of safety, a higher bar than for other food additives. Despite the lack of needed safety tests, Impossible Foods’ products containing GE heme are now widely available in supermarkets across the country due to FDA’s unlawful approval of GE heme as a color additive.

“FDA’s failure to require Impossible Foods to conduct long-term tests called for in the agency’s own authoritative guidelines means it does not have ‘convincing evidence’ that this color additive, consumed by millions, is safe,” said Ryan Talbott, staff attorney at Center for Food Safety. “The approval of soy leghemoglobin must be revoked, unless and until truly convincing evidence proves it to be safe.”

While CFS like many others avidly supports plant-based eating, enthusiasm for meatless products cannot be used as an excuse to skirt food safety laws. FDA’s dereliction of duty has resulted in the premature introduction of Impossible Foods’ products containing GE heme to restaurants and supermarkets throughout the country, and highlights a troubling deregulatory trend which prioritizes corporate profit over public health and safety.