Emulsifiers
Carboxymethylcellulose
Definition
What it is
Synthetic emulsifier: polysorbates and carboxymethylcellulose were shown in a landmark 2015 Nature study to disrupt gut microbiome composition, thin the intestinal mucus layer, and promote colitis and metabolic syndrome in mice.
On the label
How it appears on labels
- carboxymethylcellulose
- sodium carboxymethylcellulose
- cellulose gum
- e466
Regulation
Regulatory status
No bans or restrictions are recorded for this ingredient in the jurisdictions clearlabel tracks (US, EU, UK, Canada, Japan, Australia/NZ, Brazil).
Explainer
In plain language
Carboxymethylcellulose, often listed as cellulose gum, is a thickener and stabilizer made by chemically modifying cellulose from wood pulp or cotton. It has no flavor and its job is texture: keeping ingredients from separating, adding body, and controlling ice crystals. You will find it across ice cream, dressings, and many low-fat or gluten-free products.
Assessment
Why it is flagged
A 2015 study published in Nature associated the emulsifiers carboxymethylcellulose and polysorbate 80 with changes to the gut microbiome, a thinner intestinal mucus layer, and increased inflammation and metabolic changes in mice. A 2022 randomized controlled feeding study in humans, published in Gastroenterology, reported that carboxymethylcellulose altered the gut microbiota and reduced beneficial metabolites in some participants, though it did not trigger overt disease in this short trial. Regulators including the FDA and EFSA continue to authorize it, and EFSA's 2018 re-evaluation raised no safety concern at reported intakes. The human evidence is early and the animal doses were high, so this is an open research question rather than a settled harm. Clear Label flags it because some people with sensitive digestion want to test whether it tracks with their symptoms.
In the aisle
Where it commonly shows up
- Ice cream and frozen desserts
- Salad dressings and sauces
- Gluten-free breads and baked goods
- Low-fat and light dairy products
- Toothpaste and some supplements
- Reduced-sugar drinks and syrups
Practical
Reading the label
It appears as carboxymethylcellulose, sodium carboxymethylcellulose, cellulose gum, or E466. 'Cellulose gum' is the most common wording on US labels and is easy to overlook among other thickeners.
Alternatives
If you want to avoid it
Some people choose products thickened with simpler ingredients like guar gum, or whole-food versions such as ice creams and dressings with shorter ingredient lists. Comparing two similar products often turns up one without added cellulose gum.
FAQ
Common questions
Is cellulose gum the same as carboxymethylcellulose?
Yes. Cellulose gum is the common label name for sodium carboxymethylcellulose, also shown as E466 in the EU.
Does carboxymethylcellulose harm the gut?
Animal studies and one short human trial have associated it with changes to the gut microbiome and mucus layer, but the human evidence is early and does not establish disease at normal intakes. It remains authorized by the FDA and EFSA.
Why is it in so many low-fat foods?
Removing fat removes texture, so manufacturers often add thickeners like cellulose gum to restore the creamy body and mouthfeel that fat would otherwise provide.
Citations
Sources
Citation
Primary reference
About this page: the definition, label names, severity, and regulatory chips come from the clearlabel ingredient taxonomy, the same data the scanner uses to score products. Research summaries describe associations reported in published studies, not diagnoses; individual responses vary. Scan any product with clearlabel to see which of its ingredients carry flags.