We have published myriad of scientific studies linking nanoparticles like titanium dioxide * to serious harm to the digestive system, including IBD, colitis and colon cancer. (See: Serious Digestive Problems Linked to Food Additive Titanium Dioxide.) Now, a new study examined the health effects of five such nanoparticle food additives. The results revealed that two commonly used food additives known as metal oxide nanoparticles–in particular, titanium dioxide and silicone dioxide-–can have negative effects on your gut health.
What are these nanoparticles used for by food manufacturers? Titanium dioxide tends to show up as a whitening and brightening agent. Silicon dioxide tends to be added to foods to prevent it from clumping. Iron oxide tends to be added to meats to keep that red color. And zinc oxide can be used as a preservative because it is an antimicrobial.
To examine the effects of these nanoparticle food additives scientists used the intestinal tract of chickens. A chicken’s intestinal tract is comparable to a human’s; the microbiota that they have and the bacterial components have a lot of overlap with the microbiota that you see in the human digestive system.
The doses of nanoparticles that were tested reflect what is typically consumed by humans. The nanoparticles were injected into the amniotic sac of broiler chicken eggs, which are specifically bred and raised for their meat. These chickens get larger faster, so the effects of the nanoparticles are more obvious earlier in development. The amniotic sac at a certain stage of development flows through the chicken intestine.
When the chickens hatched the researchers harvested tissue from the small intestine, the microbiota and the liver. They looked at gene expression, microbiota composition and the structure of the small intestine.
The researchers found more negative effects with silicone dioxide and titanium dioxide. They also found that the nanoparticles had affected the functioning of the chicken’s intestinal lining (called the brush border membrane), the balance of bacteria in their intestinal tract and the chickens’ ability to absorb minerals.
The other nanoparticles had more neutral, or even positive, effects. Zinc oxide appeared to support intestinal development or compensatory mechanisms due to intestinal damage. Iron oxide could potentially be used for iron fortification, but with potential alterations in intestinal functionality and health.
This nanoparticle white pigment (officially classified as a food additive as opposed to a food dye) is present in processed foods common on grocery shelves, as well as in fast food and conventional restaurant foods. Frequently unlabeled in U.S. foods (though nanoparticles are required to be labeled in EU countries) this additive is used as a white pigment food coloring for processed foods such as skim milk, white cheese, yogurt, frosting/frosted foods, icing, candies, snack foods, mayonnaise, salad dressings, powdered sugar, marshmallows, pudding, breakfast toaster pastries, and non-diary coffee creamer, among many others. It is also commonly used in medicines and toothpaste.
Scientists are still determining the health safety and potential health hazards of nanoparticles in food. According to the professional organization American Society of Safety Engineers (the guide has since been removed from their website) ingested nanoparticles can be absorbed through small nodules in intestinal tissue (Peyer’s Plaques) that are part of the immune defense system. If nanoparticles enter the digestive system and proceed into the bloodstream, they can potentially move throughout the body and cause damage. Additionally, the Society concludes that “Nanoparticles may also accumulate in certain organs, disrupt and impair biological, structural and metabolic processes and weaken the immune system.” Animals studies have demonstrated that nanoparticle ingestion changes the structure of the lining of the intestinal walls. Among other potential problems, such structural changes hold the potential for over-absorption of harmful compounds. Additionally, research has indicated there are potential adverse health effects of nanoparticles on respiratory and cardiovascular systems, and studies of manufactured nanoparticles have demonstrated toxic properties. Among other health-related issues researchers are studying the potential link between Titanium Dioxide nanoparticles in food and an increased risk for inflammatory bowel diseases such as Crohn’s disease and colitis. And finally, a recent study funded by the National Science Foundation and published by the American Chemical Society found that nanomaterials in food and drinks can interfere with digestive cells, changing the normal organization and decreasing the number of microvilli (finger-like projections on the cells that help us digest food). What this means essentially is that in humans, if such an effect occurs as food and drinks pass through the gastrointestinal tract, these nanomaterials could lead to poor digestion or diarrhea. Ⓒ
Source: The Food Hacker’s Handbook: A Guide to Breaking the Processed Foods and Additives Addiction
Journal reference: Cheng, J., et al. Food-Grade Metal Oxide Nanoparticles Exposure Alters Intestinal Microbial Populations, Brush Border Membrane Functionality and Morphology, In Vivo (Gallus gallus). Antioxidants, 2023, 12(2), 431.