Health: Food colourant may be linked to intestinal inflammation in mice

Long-term consumption of the common food colourant Allura Red AC can induce mild intestinal inflammation in mice, and can increase susceptibility to inflammation in experimental models of inflammatory bowel diseases, according to a Nature Communications paper. The findings highlight the need to further investigate the potential long-term effects of food additives on health.

Many food products and drinks contain additives that improve their preservation, texture, colour and appearance. Some food additives have previously been shown to disrupt the health of the gut in animal models and lead to colitis, an inflammatory condition of the intestine. Allura Red AC is a synthetic red food dye used in some breakfast cereals, beverages, and confectioneries.

Waliul Khan and colleagues found that long-term consumption (14 weeks) of a diet containing the food colourant Allura Red AC, at a level comparable to some human foods, can induce mild intestinal inflammation in a small group of mice. The authors also found that long-term consumption of Allura Red AC (for 12 weeks) increases the likelihood of colitis in experimental mice models of inflammatory bowel disease. The authors note that the diet contained a fixed amount of Allura Red AC every day over a long time period, which would not be typical for people occasionally consuming food or drinks containing Allura Red AC. Importantly, mice who intermittently ate a diet containing Allura Red AC for 12 weeks did not develop intestinal inflammation or colitis. The authors suggest that Allura Red AC consumption increases serotonin levels, a type of chemical messenger in the large intestine, which leads to intestinal inflammation.

The authors suggest that further studies on the effects of other food dyes on intestinal inflammation, and whether similar effects could be seen in people, are needed.