Research suggests that a commonly used food additive known as carboxymethylcellulose changes the intestinal environment of healthy individuals, disturbing beneficial bacteria and nutrient levels. These results show the need for more research on the long-term effects that this food additive has on health.1✅ JOURNAL REFERENCE
DOI: 2021; DOI: 10.1053/j.gastro.2021.11.006
Carboxymethylcellulose is a synthetic member of a commonly used type of food additive, known as an emulsifier, which is put into a lot of processed foods to increase shelf life and enhance texture. Carboxymethylcellulose hasn’t been thoroughly tested in people but has been increasingly used in processed foods for some time now.
It had always been thought that carboxymethylcellulose was safe to ingest considering that it isn’t absorbed and is eliminated in the feces. Growing understanding of the health benefits that bacteria typically living in the colon provide, and could interact with non-absorbed additives, has however led researchers to test this theory.
Experiments in mice determined that carboxymethylcellulose, as well as some other emulsifiers, changed gut bacteria causing more severe disease in a variety of chronic inflammatory disorders, such as colon cancer, metabolic syndrome, and colitis. The extent to which results such as these are relevant to people had however not been looked into before.
The researchers carried out a randomized controlled study in healthy individuals who ate an additive-free diet or the same diet with carboxymethylcellulose added to it.
Because the diseases carboxymethylcellulose promotes in mice take years to manifest in people, the study focused on intestinal metabolites and bacteria. It was found that carboxymethylcellulose consumption altered the makeup of bacteria that populated the colon and reduced select species. In addition, fecal samples from carboxymethylcellulose-treated individuals exhibited a severe depletion of beneficial metabolites considered to maintain a typically healthy colon.
Colonoscopies were then carried out on the participants at the start and end of the 2-week study and a group of participants who consumed carboxymethylcellulose exhibited gut bacteria entering into the mucus, which is a feature of type 2 diabetes and inflammatory bowel diseases.
So, while consumption of carboxymethylcellulose didn’t directly lead to any disease in this study, the results support the results of animal research that consuming this additive long-term could promote chronic inflammatory disease.
