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Can Red Food Dye Cause Inflammatory Bowel Disease?

A pile of colorful candies

New research raises concerns that one of the most common dyes used in processed foods could harm gut health and increase the risk of inflammatory bowel disease.

The study published in Nature Communications focused on a synthetic food coloring commonly known as Red Dye 40. The study showed continual exposure to the dye harmed gut health and cause inflammation in mice.

The red dye is used in cereals, beverages, gelatins, puddings, dairy products and candy, according to the U.S. Food and Drug Administration. Brands that use Red Dye 40 include Skittles, Doritos and Twizzlers.

All food color additives, including Red Dye 40, require FDA approval. The agency says food dyes are safe when used in accordance with regulations, which stipulate types of foods they can be used in, maximum amounts and labeling requirements.

The safety of food dyes has been controversial, and the FDA over the years has banned several red dyes and others.

Researchers who conducted the study said the red dye increases production of the hormone serotonin in the gut of mice, altering the composition of microorganisms. That led to increased susceptibility of inflammation. The effect has not been proven in humans.

Causes and Symptoms of IBD

Inflammatory bowel disease (IBD) includes Crohn’s and ulcerative colitis. More than 3 million people in the United States have been diagnosed with IBD.

The exact causes of IBD aren’t known, but genetics, immune system function and environmental triggers are thought to play a role. Common symptoms of IBD include:

  • Persistent diarrhea
  • Abdominal pain.
  • Rectal bleeding/bloody stools.
  • Weight loss.
  • Fatigue.

It’s difficult to know exactly what in our diets might be linked to the development of IBD, says University Hospitals registered dietitian Elizabeth Traxler, RD, LD.

“We know that chronic inflammation in the gut from our environment can weaken the gut barrier lining, which allows for harmful microbes to enter and displace the healthy groups,” Traxler says.

“Studies on frequent exposure to food additives like red dye suggest it may be a contributing factor to gut dysfunction. But we don’t know at what amount and frequency it increases our risk.”

Researchers from the Canadian study said use of synthetic food dyes is on the rise, and previous studies suggest Allura Red can also affect certain allergies, immune disorders and behavior problems in children, such as attention deficit hyperactivity disorder.

The FDA says on its website it has reviewed the effects of color additives on children’s behavior and that most children have no adverse effects. The FDA acknowledges some evidence suggests that certain children may be sensitive to food dyes.

How to Know If Red Dye 40 Is in Food

It would be hard to determine if restaurant food contains the red dye. But on packaged food, the FDA requires food manufacturers to list ingredients, including color additives. Look for the following on packaging labels:

  • Red 40
  • Red 40 Lake
  • FD&C Red No. 40
  • Food Red 17
  • Allura Red AC

Traxler says the best strategy for gut health is to increase intake of foods that strengthen gut function, such as whole grains, fruits, vegetables, beans, olive oil, fatty fish, nuts, seeds and fermented foods.

Related Links

University Hospitals has a team of clinical dietitians with the knowledge and experience to help you achieve total, balanced nutrition; reach or maintain an optimum weight; and prevent or manage chronic health conditions through dietary strategies.

The University Hospitals Rainbow Pediatric Inflammatory Bowel Disease Center is the first of its kind in the region, where children and adolescents with inflammatory bowel disease (IBD) can receive the most advanced care possible.