It’s no secret that processed foods are not good for your physical health or your waistline, but a new study has highlighted how a diet rich in particular food additives might even affect your behavior too.
Neuroscientists at Georgia State University have found a link between common food additives and anxious changes in behavior, as reported in the journal Scientific Reports. Although the link has only been found in mice so far, the researchers argue that their findings could be applied to humans and used as evidence to help explain behavioral disorders.
The additives in question are synthetic emulsifiers – 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.
“We asked the question: Can emulsifiers’ effects on general systemic inflammation also be extended to the brain and to behavior?” lead researcher Geert de Vries, professor of neuroscience and associate vice president for research at Georgia State, said in a statement.
“The answer was yes.”
The team’s previous work has looked at how emulsifiers can cause slight inflammation in the intestines of mice by altering their gut microbiota, the trillions of bacteria that live in your intestinal tract. Strangely enough, this community of bacteria in your gut appears to have a deeply interconnected relationship with the central nervous system, referred to as the “gut-brain axis”. This, the researchers argue, could be the key to understanding how certain food additives might affect behavior.
“We know that inflammation triggers local immune cells to produce signaling molecules that can affect tissues in other places, including the brain,” added de Vries. “The gut also contains branches of the vagus nerve, which forms a direct information pathway to the brain.”
The experiment saw researchers put the two widely used emulsifiers into the drinking water of male and female mice. After 12 weeks, they then observed the effect on both their gut microbiota and behavior. Curiously, 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.
Next up, the team hope their work could be used by other researchers to delve deep into the mysterious, but seemingly profound, link between the gut microbiome and the human brain.
“We are currently investigating the mechanisms by which dietary emulsifiers are impacting the intestinal microbiota as well as the human relevance of those findings,” concluded study author Benoit Chassaing, an assistant professor of neuroscience.
“Our data suggest that these sex-specific changes to the microbiota could contribute to the sex differences in behavior,” noted de Vries.