Carboxymethylcellulose (CMC) vs Gelatin: which is worse?

What is Carboxymethylcellulose (CMC)?

Carboxymethylcellulose (CMC) is a cellulose derivative produced by reacting cellulose (from wood pulp or cotton) with sodium chloroacetate under alkaline conditions. As cellulose gum, it is highly water-soluble and provides viscosity and stability at low concentrations. It is one of the most widely used food hydrocolloids globally.

What is Gelatin?

Gelatin is a colorless, flavorless protein obtained by partial hydrolysis of collagen from animal sources — typically pig skin (most common), cattle bones, or fish skins. It is a thermo-reversible gelling agent, melting at body temperature (~37°C), which gives products like gummy bears and Jell-O their characteristic 'melt in mouth' property.

Documented risks

Carboxymethylcellulose (CMC): A 2015 study published in Nature (Chassaing et al., Georgia State University) found that dietary CMC at levels comparable to typical food exposure disrupted the gut microbiome in mice, reducing protective mucus layer thickness, promoting low-grade inflammation, and accelerating colitis and metabolic syndrome in genetically predisposed animals. A 2022 randomized controlled trial (CARGO trial, published in Gastroenterology) in healthy humans confirmed that CMC disruption of gut microbiota composition was observed. EFSA and FDA have not changed approval status, but these findings have generated significant scientific discussion.

Gelatin: Considered safe at food use levels. Gelatin is not suitable for vegans, vegetarians, or those observing kosher or halal dietary laws when derived from pork. Bovine-derived gelatin raised BSE (bovine spongiform encephalopathy / mad cow disease) concerns in the 1990s; regulatory measures including source and processing controls have since been implemented. Current food-grade gelatin from approved sources presents no identified health risk.