Scientists can’t prove titanium dioxide is dangerous and they can’t prove it’s safe — but this common food whitener is almost impossible to avoid, and manufacturers aren’t required to list it as an ingredient
Titanium dioxide is behind the sheen on sweets and the bleach-white colour of toothpastes and chewing gums, but new research shows it may also be behind colorectal cancer, colitis and other stomach problems.
“If there was a reason for using the titanium dioxide in food, I would say ‘OK, let’s consider it,’ but what is the reason? It’s purely esthetic,” says Wojciech Chrzanowski, an associate professor who helped lead the new study from the University of Sydney.
The food whitener is approved for use in Canada, where it only needs to be listed as “colour” on the ingredients label, according to a written statement from Health Canada.
Chrzanowski says policies like these are concerning — especially after the effects found in his team’s study — because people don’t know how much titanium dioxide is in their food.
His team gave groups of mice a regular diet and water with titanium dioxide for four weeks. The first two groups consumed two and 10 mg per kg of body weight respectively (which are rough estimates of how much humans ingest per day) while the third group was given 50 mg, a more toxic level.
In all cases, the titanium dioxide created a shield of biofilm to protect itself after entering the large intestine. This biofilm causes chemical imbalances in the gut that are linked to colorectal cancer, swelling in the intestines and other bowel diseases.
Laurence Macia, a co-author of the study and fellow associate professor at the University of Sydney, says researchers did not prove that the additive is dangerous, but certainly showed it has some effect on our bodies.
“In a short period of time, it was already affecting the immune system,” she says. “Titanium dioxide doesn’t make you sick, but I believe it does prime your system for disease. If it’s safe, we should have proof of that.”
A 2015 study in the U.S. showed some of the products with the most titanium dioxide include Mentos Freshmint Gum, Kool Aid Blue Raspberry, M&Ms Chocolate Candy and Betty Crocker Whipped Cream Frosting.
While the makers of M&Ms vowed to eliminate fake food colouring such as titanium dioxide from products by 2021, the report highlighted that many of the tested products did not include the whitener as an ingredient on the product label.
Health Canada told the National Post that manufacturers in Canada will need to start listing specific food colouring agents such as titanium dioxide by Dec. 14, 2021, but customers could still end up buying products without seeing them listed as an ingredient.
“So let’s say you see corn starch listed as an ingredient of a food product. If titanium dioxide was used to make the corn starch, they don’t need to list it. This will not change with the new food labelling regulations,” a Health Canada spokesperson wrote in an email.
Scientists studying food additives worry about the impact this could have on a vulnerable segment of the population — children.
These graphs from ‘Titanium Dioxide Nanoparticles in Food and Personal Care Products’ show how much of the additive is in food products. The top graph shows the top 20 highest concentration of titanium dioxide in commercial food items. The bottom graph shows the possible range of titanium dioxide in each type of product.
Research from Queen’s University showed when pregnant mice consumed a conservative amount of titanium dioxide nanoparticles, their babies were born with deformities, while fruit flies exposed to the whitener had fertility issues.
While these tests were done on animals and may not reflect the effects on humans, Macia says more work needs to be done on children, whose immune systems can’t handle the same amount as adults.
“I feel sorry for all the new generations of kids because they will be subject to (titanium dioxide) from birth,” says Macia.
“There’s titanium dioxide in baby formula … we consume massive amounts of it from a very young age. You can’t really avoid it.”
But the effects aren’t so clear. The stomach has a microbiota, which regulates the chemicals in your large intestine and is different in every person. That means some people have a higher tolerance to titanium dioxide and other additives, which turns the potential for negative effects into a game of Russian roulette.
Health Canada says it would consider making changes to the list of approved additives, “should new scientific data become available indicating a possible safety concern for consumers.”
Meanwhile, France is banning titanium dioxide in 2020 after being unable to guarantee it is safe, with other studies linking it to obesity and diabetes.