Food colouring nanoparticles can affect human gut

According to new research by Cornell and Binghamton University scientists, metal oxide nanoparticles - commonly used as food colouring and anti-caking agents in the commercial ingredients industry - may damage parts of the human intestine.

"We found that specific nanoparticles - titanium dioxide and silicon dioxide - ordinarily used in food may negatively affect intestinal functionality," said senior author Elad Tako, associate professor of food science at Cornell.

"They have a negative effect on key digestive and absorptive proteins." In their research, the group used human-relevant doses of titanium dioxide and silicon dioxide in the Tako laboratory's in vivo system, which offers a health response similar to the human body's.

The scientists injected the nanoparticles into chicken eggs. After the chickens hatched, the scientists detected changes in the functional, morphological and microbial biomarkers in the blood, the duodenum (upper intestine) and the cecum (a pouch connected to the intestine).

"We are consuming these nanoparticles on a daily basis," said Tako. "We don't really know how much we consume; we don't really know the long-term effects of this consumption. Here, we were able to demonstrate some of these effects, which is a key to understanding gastrointestinal health and development."

Despite the finding, scientists are not yet calling for an end to the use of these nanoparticles.

"Based on the information, we suggest simply being aware," Tako said. "Science needs to conduct further investigations based on our findings. We are opening the door for discussion."