Food additives linked to anxiety via gut-brain axis

Posted on Thu, 7 Mar 19

Artificial emulsifiers commonly used in the food industry are coming under increasing scrutiny due to potential adverse effects. An experimental study suggests they could be linked to anxiety by disrupting gut bacteria. 

Relatively recent experimental evidence shows that the artificial emulsifiers carboxylmethylcellulose and polysorbate 80, which are commonly used in some foods and food supplements, can ‘sweep the gut lining’ of its protective mucus, disrupt the microbiome and result in adverse metabolic effects resembling obesity, diabetes and inflammatory disease [1]. 

In a new study, adding carboxylmethylcellulose and polysorbate 80 to the drinking water of mice resulted in increased abdominal fat that was associated with chronic mild intestinal inflammation [2]. The emulsifiers also changed microbiota composition, with differences between males and females 

Exposure to emulsifiers altered neuropeptide expression and anxiety-like and sociability behaviour differently in male and female mice. The anxiety and behaviour changes were diverse and difficult to interpret, but collectively suggest “that emulsifier treatment fundamentally impacts the organization of behavioural patterns,” note the study investigators. 

Although there are important limitations in translating these findings to relevance for humans, the researchers who conducted the study propose “that our data support the general notion that some cases of behavioural disorders may have been impacted by exposure to modern chemical stressors and, more specifically, that synthetic dietary emulsifiers may be one such stressor.”

References: 

1. Cani PD. Metabolism: Dietary emulsifiers--sweepers of the gut lining? Nat Rev Endocrinol. 2015 Jun;11(6):319-20.

2. Holder MK, Peters NV, Whylings J, Fields CT, Gewirtz AT, Chassaing B, de Vries GJ. Dietary emulsifiers consumption alters anxiety-like and social-related behaviors in mice in a sex-dependent manner. Sci Rep. 2019 Jan 17;9(1):172.