Common food additives may promote anxiety, according to researchers at Georgia State University. They say emulsifiers commonly found in processed foods to improve texture and extend shelf life, may adversely affect anxiety related and social behaviors in mice.

Lead researcher, Geert de Vries, professor of neuroscience and associate vice president for research at Georgia State, says, “We asked the question: Can emulsifiers’ effects on general systemic inflammation also be extended to the brain and to behavior? “The answer was yes.”

Though the researchers could not pinpoint the exact mechanism by which emulsifiers contribute to behavioral changes, they said inflammation triggers local immune cells to produce signaling molecules that can affect tissues in other places, including the brain.

Researchers put two widely used emulsifiers into the drinking water of male and female mice, specifically polysorbate 80 and carboxymethylcellulose – that are often added to foods such as cookies, cake, bread, and margarine to improve their texture as well as extend their shelf life. After 12 weeks, they then observed the effect on both their gut microbiota and behavior. The emulsifiers seemed to affect the male and female mice differently. The males appeared to experience more anxiety-like behavior, while the females' change in behavior was characterized by reduced social behavior. According to de Vries, this could perhaps be explained by sex differences in the immune system and the makeup of gut bacteria.