E551 is a widely used additive in the food industry that we might consume daily without even realising it. Researchers at France’s National Research Institute for Agriculture, Food and Environment (Inrae) now suggest it may not only promote gluten intolerance, but also aggravate the inflammation associated with celiac disease.

In soups, instant coffee, chocolate, and even in cereal-based baby foods, E551 – otherwise known as silica dioxide – is everywhere. Used by food manufacturers as an anti-caking agent, it prevents the formation of lumps while preserving the taste and texture of foods.

This additive is used in many products, so much so that we’re likely to be exposed to it daily. “E551 is widely used as an essential processing aid in various food transformation processes. In such situations, it does not appear in the ingredients list on the packaging, even if it is present in the final product.

“Thus, we are exposed to low doses of E551 on a daily basis via the food we consume,” the researchers explained.

While the French consumer group UFC Que Choisir has classified the additive as “not recommended” owing to the potential presence of nanoparticles and a possible toxic effect on the intestines, this recent study from Inrae highlights how this common food additive may promote the development of gluten intolerance.

“This research is the first to underscore the potential toxicity of this food additive, which is currently considered to be safe for consumption,” the study’s news release noted.

The findings suggest that silica dioxide prevents the production of anti-inflammatory compounds needed to prevent reactivity in the intestine, by reducing the number of intestinal immune cells. Thus, ingesting E551 appears to aggravate the inflammation associated with celiac disease.

“Taken together, these results indicate that chronic exposure to E551 via dietary sources could promote the development of celiac disease in people genetically predisposed to the condition,” the researchers concluded in their paper, published in the journal Environmental Health Perspectives.