TORONTO – A synthetic dye newly banned from the U.S. food supply will remain available in Canada, where the federal regulator has deemed it is not a health risk to the general population.
With the latest decision by the U.S. Food and Drug Food Administration, Canada stands as a bit of an outlier on the food additive known as Red 3, which is also restricted for use in food in Europe, Australia and New Zealand.
McGill University’s Joe Schwarcz agreed with Health Canada’s position that evidence demonstrating human safety concerns is lacking, but he nevertheless would like to see the dye banned because he says it adds no nutritional value while making ultra-processed foods more attractive to consumers.
“The important issue is: when you’re going to put something into food, it should be because it serves some sort of benefit, other than just making something look more appealing,” said Schwarcz, director of McGill University’s Office for Science and Society.
He said there are plenty of natural alternatives with no shadow of toxicity fears such as beet juice extract and anthocyanins extracted from berries.
Also known as erythrosine or FD&C Red No. 3, the dye is primarily used in treats including candy, cakes, cookies and frostings to give foods and drinks a bright, cherry-red colour.
The FDA banned the dye over potential cancer risk, noting two studies found it caused cancer in lab rats with a “rat-specific hormonal mechanism” that does not exist in humans.
It said the measure was a “matter of law,” because a legal provision requires it to ban food additives found to cause cancer in humans or animals.
McMaster University scientist Waliul Khan says that while certain effects on rats do not necessarily translate to humans, he sees value in heeding the findings of animal studies that flag potential safety issues for additives that can be easily avoided.
“When there is emerging evidence that this is harmful — even in animals — why we are going to keep it in our food?” said Khan, a professor in the department of pathology and molecular medicine.
Khan said he’d like to see a warning label on foods containing synthetic dyes, also expressing concern over red dye No. 40, sometimes labelled allura red.
He said an animal study he published in 2022 found long-term consumption of allura red can potentially trigger inflammatory bowel diseases.
“When we gave it continuously to a mouse for 12 weeks, it caused some harmful effects in the gut and increased the severity of colitis. But when we gave it once a week, we didn’t see that serious effect,” said Khan.
“Of course, there should be more studies, potentially, with the human subject.”
Two other papers published in 2023 by University of Guelph researchers examined how some dyes break down in the gut, finding they could potentially result in toxic byproducts.
Microbiologist Emma Allen-Vercoe, who was involved in both studies, said in a release that the studies call for updated regulations to take into account the way compounds are metabolized.
Khan said he is investigating the safety of other dyes and he hoped that increased attention brought by the FDA ban on Red 3 would spur funding for more studies. He noted difficulties in the cost of mounting a trial with a large sample, as well as the ethics of attempting to study on humans a substance known to harm animals.
Health Canada also diverges from the FDA in permitting Red 3 in cosmetics — the FDA barred it from use in makeup in 1990 due to a study that found it caused cancer when eaten by rats.
Schwarcz again chalks that up two very different regulatory systems, insisting: “There is actually no evidence at all that it would be a danger in cosmetics.”
Health Canada said if new scientific data reveals a human health risk to using the dye in food or drugs, it would take action, “including, if necessary, no longer permitting it to be used as a colouring agent in food and drugs.”
It described the FDA ban as a “legal requirement” triggered by the two rat studies.
“Studies in other animals and in humans did not show these effects, and claims that the use of this colour in food puts people’s health at risk are not supported by the available scientific evidence,” it said in an emailed statement early Wednesday evening.
Health Canada said it reviewed a safety evaluation conducted by a joint committee for the United Nations and World Health Organization in 2018. The joint UN/WHO committee looked at studies that involved humans and animals, and found no safety concerns for the dye as a food additive.
This report by The Canadian Press was first published Jan. 16, 2025.
