Common food coloring can trigger inflammatory arch

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Tuesday, December 20, 2022 at 11am ET

Common food coloring may trigger inflammatory bowel disease, McMaster researchers say

Hamilton, ON (December 20, 2022) — Long-term consumption of Allura Red food coloring may be a potential trigger of inflammatory bowel diseases (IBDs), Crohn’s disease, and ulcerative colitis, says Waliul Khan of McMaster University. Researchers using experimental animal models of IBD have found that continuous exposure to Allura Red AC impairs gut health and promotes inflammation.

The dye directly disrupts gut barrier function and increases the production of serotonin, a hormone/neurotransmitter found in the gut, which subsequently alters the composition of the gut microbiota, leading to increased susceptibility to colitis.

Khan said Allura Red (also called FD&C Red 40 and Food Red 17) is a common ingredient in candy, soft drinks, dairy products and some cereals. Dye is used to add color and texture to foods, often to appeal to children.

The use of synthetic food colors such as Allura Red has increased significantly in recent decades, but there have been few previous studies on the effects of these colors on gut health. Khan and his team published their findings in Nature Communications🇧🇷 Yun Han (Eric) Kwon, who recently completed his doctorate in Khan’s lab, is the first author.

“This study demonstrates significant harmful effects of Allura Red on gut health and identifies gut serotonin as a critical mediator of these effects. These findings have important implications for the prevention and treatment of intestinal inflammation,” said Khan, senior author of the study, professor in the Department of Pathology and Molecular Medicine and principal investigator at the Farncombe Family Digestive Health Research Institute.

“What we found is both impressive and alarming, as this common synthetic food coloring is a possible dietary trigger for IBDs. This research is a significant step forward in making the public aware of the potential harms of the food dyes we consume on a daily basis,” he said.

“The literature suggests that consumption of Allura Red also affects certain allergies, immune disorders and behavioral problems in children, such as attention deficit hyperactivity disorder.”

Khan said IBDs are severe chronic inflammatory conditions of the human gut that affect millions of people worldwide. While their exact causes are still not fully understood, studies have shown that dysregulated immune responses, genetic factors, gut microbiota imbalances, and environmental factors can trigger these conditions.

In recent years, there has been significant progress in identifying susceptibility genes and understanding the role of the immune system and host microbiota in the pathogenesis of IBDs. However, similar advances in defining environmental risk factors are behind, he said.

Khan said that environmental triggers for IBD include the typical Western diet, which includes processed fats, red and processed meats, sugar and a lack of fiber. He added that the Western diet and processed foods also include high amounts of various additives and dyes.

He added that the study suggests a link between a commonly used food dye and IBDs and warrants further exploration between food dyes and IBDs at experimental, epidemiological and clinical levels.

The study was funded by the Canadian Institutes for Health Research.



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Veronica McGuire

Media relations

Faculty of Health Sciences

McMaster University


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