Carboxymethylcellulose (CMC) may not be a household name, but chances are, you’ve consumed it. As the world’s most widely-used cellulose-based emulsifier, CMC can be found in nearly every type of processed food. However, recent research has linked CMC to a variety of gastrointestinal issues, casting a shadow on its widespread use in the food industry.

What is CMC?

Carboxymethyl cellulose (CMC) is a commonly used stabilizing and thickening agent in a wide range of products, including ice cream, milk, fruit juice, toothpaste, detergents, water-based paints, chewing gum, dye, protein drinks, laxatives, and many other processed items. It is a highly versatile substance that is derived from cellulose, an organic compound, and is considered nontoxic and hypoallergenic.

As an emulsifier, CMC improves the experience and longevity of food by easily absorbing and retaining water, making it a ubiquitous agent in the food industry. Despite having no nutritional value and being indigestible by humans, CMC has been deemed safe for consumption since the 1960s. It is often used in the production of baked goods due to its calorie-free and gluten-free nature. Additionally, CMC is used as a texture enhancer, creating a thicker and creamier taste experience in many sauces, jams, and even sausages.

On product labels, CMC may also be referred to as sodium carboxymethyl cellulose or sodium CMC. While CMC has been widely used for decades, recent research has raised concerns about its impact on gut health. Studies have shown that CMC can cause stomach pain, loss of gut bacteria diversity, and symptoms associated with irritable bowel disease and gut inflammation. This has prompted a need for further research into the effects of CMC and other emulsifiers on human health.

The Truth About CMC 

New research published in the Gastroenterology Journal in November 2021 sheds light on the harmful effects of Carboxymethyl cellulose (CMC) on gut health. A controlled-feeding study conducted on healthy volunteers revealed that those who consumed CMCs experienced stomach pain, loss of gut bacteria diversity, loss of short-chain fatty acids and amino acids, and symptoms associated with irritable bowel disease (IBD) and gut inflammation.

This is not the first study to find fault in CMC or emulsifying agents in general. In 2015, a study published in Nature found a direct link between dietary emulsifiers and low-grade inflammation, changes in gut microbiota, obesity/metabolic syndrome, and colitis in mice.

These findings suggest that the widespread use of emulsifying agents like CMC may be contributing to the increase in IBD, colon cancer, and chronic inflammatory conditions in human populations. By altering the composition of the gut microbiome and the number of metabolites present, these agents can cause lasting harm to gut function and health.

This study also underscores the need for further research into the effects of CMC and other emulsifiers. According to co-senior author Dr. James Lewis of the University of Pennsylvania, the study “provides a general blueprint to carefully test individual food additives in humans in a well-controlled manner.” Large-scale research into the composition of processed foods, especially components long believed to be safe and nontoxic like CMC, is crucial.