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What Is Red No. 3 (Erythrosine) And Why It's in Your Food?

Here's the lowdown on whether brightly colored red foods are safe.
FACT CHECKED BY Mura Dominko

There's no doubt that a bright red treat can catch your eye and make your mouth water, but it might also contain something you weren't expecting. There's a chance that the radiantly enticing red color was achieved by using Red No. 3 (erythrosine) in your food item. This food dye can be found in things like candy and popsicles, according to Healthline, while Science Direct notes it's also used in pastries and breakfast cereals. And while this substance is currently approved by the Food and Drug Administration (FDA) for use in food, could it actually have harmful effects on your health?

Red No. 3 has limited use in the U.K. while in the United States an alternative is often preferred. It was approved by the FDA along with other dyes by 1931. Yet, in 1990, The New York Times reported that the FDA had banned many uses of Red Dye No. 3, due to studies that showed the color additive, used in very high doses, can cause cancer in laboratory mice. Despite that, this dye is still in our food supply today, over 20 years later.

For more, check out 8 Worst Fast-Food Burgers to Stay Away From Right Now.

red popsicle
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So is Red No. 3 harmful? Dr. Louis W. Sullivan, the Secretary of Health and Human Services in 1990, told The New York Times that "[t]he actual risk posed by Red No. 3 is extremely small." When it comes to how small that risk was considered to be, the FDA explained that the "risk of getting cancer from Red No. 3 is no larger than 1 in 100,000 over a lifetime of consumption." For context, the danger posed by natural disasters is 70 in 100,000, while railroad accidents and air disasters are 6 in 100,000.

"The major confusion here lies in the variations of regulations across different countries," Rachel Fine, registered dietitian and owner of New York City's To The Pointe Nutrition, tells Eat This, Not That! "Here in the U.S., food safety regulatory agencies utilize a risk-based approach and since the amounts of these ingredients in our food are negligible, they are not flagged as a reason to avoid them."

So what should we make of that rat study? Could this food dye pose a risk of cancer to humans?

"Because erythrosine has been found to cause cancer in rats, some people may worry that it may be dangerous for humans also," explains Dr. Kelly Johnson-Arbor, medical toxicologist and co-medical director of the National Capital Poison Center. "It's important to remember that rats are very different than human beings, and some chemicals that are toxic to rats and other laboratory animals are not harmful to humans due to differences between the species." Additionally, she points out that "toxicity studies in laboratory animals often involve the use of very high doses of chemicals, much larger than would be expected after human exposure. Since rats are much smaller than humans, these high doses correspond to exposures that would never be encountered by most humans."

Another fact that might put your mind at ease is that erythrosine has very poor absorption into the human body after consumption, and only about 1% of all erythrosine is actually absorbed into the bloodstream after ingestion, according to Johnson-Arbor. "The body does not metabolize erythrosine, and it exits the body unchanged in the feces. Because of all of these characteristics, human exposure to erythrosine in foods is likely minimal. It is likely safe for most humans to consume erythrosine, or red dye number 3, on an occasional basis."

While occasionally consuming Red No. 3 may not harm your health, it still might be best to avoid it as much as possible. To do so, Johnson-Arbor recommends carefully reviewing ingredients listed on food packaging and choosing foods that use natural dyes or colorants. "Eat a well-balanced diet, and enjoy processed foods in moderation to avoid exposure to synthetic food dyes and other potentially dangerous chemicals," she says.

To find out more about what kind of dyes you might not have realized you've been eating, be sure to read 17 Surprising Foods That Contain Chemicals & Food Dyes.

Desirée O
Desirée O is a freelance writer who covers lifestyle, food, and nutrition news among other topics. Read more about Desirée