Regular consumption of a common synthetic food coloring commonly found in candy, soda, and cereal might impact our gut health — and not in a good way.
A new study in mice suggests the dye Allura Red AC Regular consumption can cause intestinal inflammation. When consumed by younger mice, it seemed to increase the risk of gut problems later.
“Regular” in this case means daily exposure, something that might only apply to hardcore fans of colorful candies and lively breakfast cereals. What we see in mice also doesn’t necessarily translate cleanly to humans.
But discoveries like these can tell us a thing or two about the interactions between our diet and the biology of our gut that warrant further investment.
This isn’t the first time scientists have uncovered concerns about Allura Red (aka FD&C Red 40 and Food Red 17). Along with other dyes made from organic compounds known as azo dyesthe food coloring is poorly absorbed in the gut and can be eaten by microbes in the gut, which may well lead to poisonous and possibly carcinogenic Effects.
previous studies have suggested that food coloring consumption is linked to immune responses, unwanted allergic reactions in children, and even behavioral disorders such as hyperactivity and attention problems.
These first insights have prompted many European nations to do so strictly control Allura Red’s use if not forbid it entirely. Products containing synthetic food coloring must now also carry a label warning of possible health effects. in the United States and CanadaOn the other hand, the synthetic ingredient can still be used to color food as long as the products list the colorants in their ingredients list.
Today the The use of allura red is increasing alongside a rising demand for ice cream, candy, gelatin desserts and other colorful foods that feature prominently in the Western diet.
Comparatively little research has been done on the ingredient’s effects on our gut health outside of studies examining Allura Red’s potential impact on various behavioral disorders in children, although new evidence raises serious concerns.
“What we found is striking and alarming given that this common synthetic food coloring is a possible dietary trigger for IBDs,” says Immunologist Waliul Khan from McMaster University in Canada.
“This research is a significant advance in raising public awareness of the potential harms of food coloring that we consume every day.”
When ingested, Allura Red is metabolized by gut bacteria and previous studies in mice have shown that low doses of the dye can damage DNA in the colon.
To further study this effect, Khan and colleagues tested a handful of synthetic dyes, including Brilliant Blue and Sunset Yellow, on human tissue and mice to model their effects on inflammatory bowel diseases (IBDs) such as Crohn’s disease and ulcerative colitis.
When human gut cells grown in the lab were exposed to dyes for 24 hours, the researchers found that each individual dye had an effect. In the presence of the dyes, the human gut cells began secreting more serotonin from the colon than they otherwise would have done. They also found that Allura Red had the greatest impact.
By the way, seratonin – a signaling molecule involved in many biological processes closely related to IBD.
Based on the results of the cell experiments, Khan and colleagues tested the effects of Allura Red on mice.
Animals fed a regular diet without food coloring for 12 weeks showed no significant changes in their gut, while mice given a daily dose of Allura Red showed mild inflammation of the colon. Remarkably, a barrier normally formed by intestinal cells was also compromised.
Serotonin was a key mediator of these changes and appeared to prime gut cells for the toxic effects of food coloring.
When mice were bred to be deficient in serotonin transporter proteins, serotonin levels in the colon increased, as did inflammatory markers, leading to more inflammation.
“This study demonstrates significant deleterious effects of Allura Red on gut health and identifies gut serotonin as a critical factor mediating these effects,” says Khan.
“These findings have important implications for the prevention and treatment of inflammatory bowel disease.”
Further experiments showed that daily consumption of Allura Red altered the animals’ gut microbiome, which could explain how serotonin might affect the colon, but that remains unclear. Its role in shaping the microbiome is likely to be complex, but given how easily food dyes are gobbled up by resident gut microbes, there’s a possibility that this dye is wreaking havoc on the system’s normal activity.
More research is needed to confirm whether the results are comparable in humans, but given the widespread use of synthetic dyes, it’s crucial that scientists figure out how they might affect our gut health in the long term.
If food coloring like allura red can actually make children more susceptible to IBD in the long run, this could partially explain why cases of Crohn’s disease and ulcerative colitis occur are on the rise in older adults.
“This is particularly important as synthetic colors are a practical and cost-effective alternative for food manufacturers to make food even brighter and more appealing to consumers, especially young children,” the authors say write.
“This study will therefore not only stimulate a review of its use in many industries, but also increase public awareness to prevent adverse health outcomes,” they said conclude.
The study was published in Nature.
