The data and puzzling history behind California’s new red food dye ban

Last weekend, California outlawed a common red food dye that is otherwise deemed safe by the Food and Drug Administration—the first such ban in the country and one that puzzlingly comes over three decades after the FDA determined the dye causes cancer in rats and banned it from lipsticks and other cosmetics, but not foods. The dye is FD&C Red No. 3, also known as red dye No. 3. Today, it is found in thousands of food products—from Brach's Candy Corn and varieties of Nerds, Peeps, Pez, candy canes, Fruit by the Foot, to Entenmann's Little Bites Mini Muffins, Betty Crocker mashed potatoes, fruit cocktail, PediaSure nutritional shakes, and MorningStar Farm's veggie bacon strips. But, back in 1990, the FDA carefully reviewed decades' worth of animal studies on red dye No. 3 and determined that "FD&C Red No. 3 has been shown to induce cancer in appropriate tests," and is therefore "unsafe for use in externally applied drugs and externally applied cosmetics and cannot be listed." Even though the risk appeared small, the agency's decision hinged on the Delaney Clause of 1958, which requires the FDA to ban any food additive that is shown to induce cancer in humans or animals. As the FDA described it at the time, because of that clause, "products shown to have carcinogenic effect in laboratory tests, no matter how small, cannot be approved for use by the FDA.'' But, due to bureaucratic quirks, the FDA's determination only applied to cosmetics and externally applied products—even though the animal studies that proved a link to cancer were based on feeding rats the dye, not applying it to their skin or fur. The FDA had determined back in 1969 that, based on data at that time, red dye No. 3 was safe to add to foods, dietary supplements, and ingested drugs. As such, the agency permanently listed it as a safe food additive. Soon after, makers of personal care products also wanted to get permanent approval to add red dye No. 3 in their products. At that point, the dye was only "provisionally" listed for external use, and the industry needed to conduct scientific studies to prove to the FDA that it was safe in those products, too. But, in 1977, as that work was ongoing, the FDA revised its requirements, forcing the industry to conduct new chronic toxicity studies—the studies that would show increased rates of cancer in rats. Between 1977 and 1990, the FDA granted the industry numerous extensions to produce scientific data showing red dye No. 3 was safe—but they ultimately couldn't.

Dye data

The FDA's determination that red dye No. 3 causes cancer in rats was largely based on just two industry studies. The studies followed rats chronically fed red dye No. 3, at various dosages, for up to 28 months, some starting in utero. In the first study, red dye No. 3 made up 0.1, 0.5, or 1 percent of the test rats' diets, alongside two control groups of rats that got no dye. The industry scientists reported no differences in the groups, but the FDA conducted its own microscopic examination of the animals' tissues. This revealed statistically significant higher incidences of male rats with thyroid tumors and cancers, the FDA concluded. In the second study, there were just two groups of rats—a control group and one fed a diet that was 4 percent red dye No. 3—a high dose. Again, the FDA found male rats had higher rates of thyroid tumors (14 of 68 rats fed the dye (20.6 percent) vs 1 of 68 control rats (1.5 percent)). The rate of carcinomas was also higher in the male rats fed the dye (7.5 percent vs 1.5 percent). Overall, the FDA found the male rats fed the dye had a higher rate of tumors and cancers than the control rats (26.5 percent vs 2.9 percent). At the FDA's request, the National Toxicology Program conducted a peer review of the studies and concluded, like the FDA, that red dye No. 3 is an animal carcinogen. After the two damning rat studies, industry researchers conducted several other studies that attempted to identify the mechanism by which red dye No. 3 was causing the tumors—and argue why said mechanism wouldn't be relevant to humans. But the studies failed to prove any such mechanism. The FDA determined in 1990 that the mechanism remained unknown, but "that FD&C Red No. 3 causes cancer in animals is unrefuted." Still, upon banning red dye No. 3 from cosmetics in 1990, the FDA downplayed its dangers, noting that the risk of developing cancer from the dye appeared to be less than 1 in 100,000—small compared to the risk of natural disasters (70 in 100,000) or the risk of a train or plane crash (6 in 100,000). Representatives of the food industry had similar messages, with one industry study reportedly saying a person would have to eat 724,000 cans of fruit cocktail a year for 70 years to ingest an equivalent amount of red dye No. 3 as the rats fed the high 4 percent diet dose. But, given the FDA is bound by the Delaney clause, the agency said it would "take steps" to remove red dye No. 3 from foods as well. And consumer advocates cheered the thought—however slight the cancer risk, it easily outweighs the frivolousness of neon peeps and freakishly red fruit cocktail cherries, they have long since argued. But, 33 years later, the FDA has still not banned red dye No. 3 from foods.

FDA dodge

In a lengthy emailed statement to Ars, an FDA official entirely dodged the question of what was holding up the dye's removal. The official seemed to acknowledge that the agency should act, writing that when the agency identifies "new data and information that indicates the use of an ingredient is unsafe, we take steps to protect public health, which can include revoking authorizations or approvals for certain uses…." But, the officials seemed to suggest the agency might be concerned by the ramifications of ditching the dye. "It is important that scientific information and data are considered when making changes that could impact the food supply, such as a state-initiated ban of ingredients in food," the statement read. "Such actions could potentially disrupt the food supply, leading to less product availability and/or higher prices." When the agency banned red dye No. 3 from cosmetics in 1990, one industry analysis extended the possibility to foods. Without the bright-red cherries in otherwise drab fruit cocktails, the analysis claimed, sales of such products would fall by 40 percent, leading to an economic hit of up to $246.7 million. But, at this point, such concerns seem overblown, according to ban proponents. California Governor Gavin Newsom, who signed the ban into law Saturday, noted that the state ban won't lead to products being stripped from shelves. For one thing, it doesn't take effect until January 1, 2027, giving manufacturers plenty of time to adjust. And red dye No. 3 is already banned or restricted elsewhere, including the European Union, thus alternative ingredients are readily available. Still, because California has such a massive economy, it's likely the state ban will lead to nationwide reformulations of common products. "This is a milestone in food safety, and California is once again leading the nation," Ken Cook, president of Environmental Working Group, said in a statement. "We applaud Gov. Newsom for signing this landmark bill and putting the health of Californians before the interests of industry." Such consumer advocates have long pushed for bans on artificial dyes in foods, many of which have been linked to behavior problems and hyperactivity in children, especially yellow No. 5, yellow No. 6, and red No. 40. The bill Newsom signed on Saturday also bans three other food additives: Potassium bromate, used in baked goods, which has also been linked to cancer in lab animals; brominated vegetable oil, used to keep fruit-flavored drinks like Mountain Dew from separating, and may be harmful to the nervous and respiratory systems; and propylparaben, a preservative that may disrupt hormones. These have also been banned or restricted by the EU and elsewhere. The FDA official's emailed statement did note that "the FDA is working on a proposed rule to amend our regulations to remove the authorization of the use of brominated vegetable oil (BVO) as a food ingredient."