Earlier this week the U.S. Food and Drug Administration revoked the authorization of the dye Red No. 3, which is used in a variety of foods and medications. This artificial dye, which is made from petroleum and had been found to cause cancer in rats, was removed in response to a 2022 petition from the Center for Science in the Public Interest and other advocacy groups.
The cherry-red coloring agent is found in foods such as candies, Maraschino cherries, and strawberry-flavored milk drinks and in medicines such as cough syrups. Manufacturers of foods and ingested drugs have until January 15, 2027, and January 18, 2028, respectively, to remove the dye from their products.
Food safety activists had long called for Red No. 3’s removal, citing concerns about its possible carcinogenicity in humans, as well as some evidence that similar dyes may contribute to behavioral problems in children—including attention deficit hyperactivity disorder (ADHD).
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Scientific American spoke with experts about why this red dye is being banned, how much exposure may be harmful and how it compares with other food colorings.
Which red dye is being banned?
Its official name is Red No. 3.
What foods or medicines contain it?
It’s found in candies, fruit juices, snack foods, Maraschino cherries and strawberry-flavored milk. It’s also found in some medications such as cough syrups.
Why was it banned?
Male rats developed thyroid tumors after being exposed to high levels of the dye in lab studies. But according to the FDA, the rats developed cancer through a hormonal mechanism that does not occur in humans—and studies in humans and other animals have not shown similar effects. Nevertheless, the dye was removed under the Delaney Clause of the Federal Food, Drug, and Cosmetic Act, which bans FDA authorization of a food or color additive that has been found to cause cancer in humans or animals.
Concerns have also been raised that some other artificial dyes, including another red dye called Red No. 40, may contribute to hyperactivity in children.
Why did it take so long for the U.S. to ban this compound in food?
The FDA has banned the use of Red No. 3 in cosmetics and topical medications since 1990. The European Union banned the dye in food (except cocktail cherries) in 1994, and in 2023 California banned it as well.
“The FDA has a really large mandate, and they have focused primarily on drugs. Within the food realm, they focused on food safety with a specific eye on infectious diseases like [Escherichia coli infection],” says Sheela Sathyanarayana, a professor of pediatrics and an adjunct professor of environmental and occupational health sciences at the University of Washington and Seattle Children’s Research Institute, but “where there’s been a hole or a gap is in food safety related to additives and environmental exposures and contaminants.”
The FDA, under the Biden administration, recently created a new food chemical safety office. “I am hopeful, with that new office opening, that they will be able to kind of assess in a more holistic way multiple different exposures, from food additives to contaminants,”Sathyanarayana says.
Red No. 3 is also found in some cough medicines.
Food Drink and Diet/Mark Sykes/Alamy Stock Photo
How much of this red dye do you need to consume for it to be harmful?
The relevant studies exposed rats to doses of the dye that were likely much larger than what a human would normally consume. It’s very hard to do studies on the toxic dose in humans because it’s unethical to conduct randomized, controlled trials that give people food with large amounts of certain additives. Most human studies of food ingredients are epidemiological: they involve asking people to remember what foods they’ve eaten and in what amounts, which is notoriously unreliable.
According to physician Melinda Ring, director of the Osher Center for Integrative Health at the Northwestern University Feinberg School of Medicine, the acceptable daily intake of Red No. 3 is a maximum of 0.1 milligram per kilogram of body weight per day. “For perspective, this equates to roughly 12 red gummy bears for a child and 36 for an adult based on typical concentrations,” Ring wrote in an e-mail to Scientific American. “However, research indicates cumulative exposure to toxins can have additive effects, making it safer to avoid synthetic dyes entirely rather than consuming a ‘tolerable’ amount.”
Do other artificial food dyes also pose health risks?
Red No. 3 may be one of the most well-studied dyes, but others, such as Red No. 40, have also been linked to health concerns. Some studies have tied red dyes to an increased risk of behavioral disorders such as ADHD.
Now that Red No. 3 has been banned, it will be interesting to see if the FDA bans some of these other dyes, says Tracy Crane, an associate professor of medical oncology and director of lifestyle medicine, prevention and digital health at the University of Miami’s Miller School of Medicine.
Should you avoid eating anything with artificial dyes in it?
In general, it’s best to avoid large amounts of foods or medicines that contain artificial dyes. “I always tell people [to consume] sparingly,” Crane says. “What I tell people is: ‘It’s always better to not be putting artificial substances in your body. If something was not made by nature that color, it’s probably synthetic.’”Instead there are safer natural alternatives, such as dyes made from beets, carrots or even insects.
One problem with foods that contain artificial dyes is that they often attempt to target children by using bright, cheery colors. “We need to change expectations of what food should look like,” Crane says.
And it’s not just artificial dyes that may be harmful; many of the foods that contain these dyes also contain a lot of sugar. “From a cancer prevention standpoint, it is recommended to consume less than 10 percent of calories from added sugar,” wrote Hannah Manella, a registered dietician at Northwestern Medicine, in an e-mailed statement to Scientific American.
Many of these foods are also ultraprocessed, and some studies have linked foods in this category to various diseases or health problems. “Choosing whole, unprocessed foods or carefully reading ingredient labels can help consumers reduce exposure to synthetic dyes and other environmental toxins while supporting a cleaner, safer food supply,” Ring says.
