Health Risks from Prepared Soups Food additive may promote intestinal diseases

Anti-clogging agent: Food additive affects the immune system of the intestine
The anti-caking agent silicon dioxide E551 has been used for decades in the food industry and has been considered harmless so far. However, Swiss scientists have now discovered that these tiny nanoparticles can affect the gut's immune system.

Additives in processed foods
The food industry relies on more and more additives in processed foods. Even for organic food, more and more such substances are approved. Among other things, the respective substances should serve to extend the shelf life, to protect against undesirable color changes, to improve the consistency, to avoid the addition of sugar or to standardize the color of the product. A widely used additive is silica E551. Although this was long considered harmless, but now scientists have found that it can affect the immune system of the intestine.

The anti-caking agent silica E551 is used inter alia in slurry soups. For a long time, it was considered safe, but researchers have now found that it can affect the immune system of the gut. (Image: Huna / fotolia.com)

E551 was long considered harmless
Anti-caking agents ensure that dry foods such as instant soups, instant coffee or seasoning powder remain free-flowing.

One such agent is silica E551. The ultrafine powder extracted from quartz sand has been widely used in the food industry for over 50 years and has been considered harmless to date.

But scientists of the Swiss National Research Program "Chances and Risks of Nanomaterials" have now discovered that these nanoparticles can influence the intestinal immune system.

Inflammatory reaction set in motion
"So far, it was assumed that these nanostructured particles are completely inert," said Hanspeter Nägeli from the Institute of Pharmacology and Toxicology of the University of Zurich in a statement.

But now he and his colleagues have found that these particles are able to activate certain immune cells.

"We have shown that quiescent dendritic cells are stimulated in contact with nanosilica and initiate an inflammatory-like reaction," says Nägeli.

The results, which were published in the journal "Particle and Fiber Toxicology", make listen, because in the immune system of the intestine, the dendritic cells play a crucial role: they maintain a dynamic balance between defense reactions and tolerancing.

The dendritic cells are significantly involved in the fight of the immune system against pathogens and foreign bodies. But they also coordinate the benevolent response to dietary constituents or representatives of the normal intestinal flora.

Bowel diseases depend on various factors
As has been shown in experiments with mouse cell cultures, the dendritic cells take up the nanosilica in their cell interior. That wakes her from her sleep. They begin to excrete a particular inflammatory signaling molecule.

Whether such processes may shift the immunological balance of the human gut towards increased defense, the researchers do not know.

But their findings may explain the observation that inflammatory bowel disease spreads as more people consume finished products.

"It's not about fanning fear. Inflammatory bowel diseases depend on a variety of factors, "said Nägeli. And nano-silicones in the diet make at most a small piece of puzzle in the overall picture of these complex diseases.

Nonetheless Nägeli advises, due to his results, to be more cautious in handling these particles in the diet. "Your massive use must be reconsidered," the researchers write in their technical contribution.

Criticism of the current safety assessment
In another article in the "Journal of Nanobiotechnology" Nägeli criticizes the current safety assessment of nanosilica.

"In the toxicological analyzes no immunological criteria are raised," said the expert. In addition, in the feeding experiments with rats at the highest dose, liver damage was observed - but not taken into account in the risk evaluation.

A connection with nanosilica is not proven, but can not be ruled out in the current state of knowledge. "We therefore advocate the application of the precautionary principle and the review of the limit value in the diet," said Nägeli. (Ad)