Polysorbate 80
A synthetic emulsifier made from sorbitol and oleic acid, used to blend water and fat together in processed foods.
Animal studies show polysorbate 80 disrupts the gut's protective mucus layer and alters gut bacteria, promoting low-grade inflammation and metabolic changes. Human studies remain limited but point in the same direction.
What is it?
Polysorbate 80 (also called polyoxyethylene sorbitan monooleate) is a synthetic surfactant made by reacting sorbitol with oleic acid and then treating the result with ethylene oxide. The '80' refers to the oleate fatty acid chain. It is part of the polysorbate family (E432 to E436), all of which work similarly.
What does it do?
It acts as an emulsifier by reducing surface tension between oil and water, allowing them to mix into a stable blend. It also coats particles to keep them evenly dispersed, prevents separation in dressings and creams, and improves the texture and shelf life of baked goods and ice cream.
Where you will see it
Ice cream and frozen desserts, salad dressings, mayonnaise, whipped cream, cakes and baked goods, chocolate-coated products, low-fat spreads, and some vitamin supplements. On a UK label it appears as 'emulsifier: polysorbate 80' or 'emulsifier: E433'.
What the science says
Gut mucus and microbiome disruption
The most significant research concern comes from animal studies showing that polysorbate 80, fed at doses intended to model human dietary intake, erodes the mucus layer lining the gut wall, encourages bacteria to sit closer to the gut lining than they should, and shifts the composition of gut bacteria in ways linked to inflammation. These changes were associated with metabolic syndrome (weight gain, raised blood sugar, increased fat around organs) in healthy mice, and triggered full colitis in mice genetically susceptible to bowel inflammation.
Mice consuming polysorbate 80 in drinking water at 1% concentration developed thinning of the intestinal mucus layer, altered gut microbiota composition, low-grade inflammation, and features of metabolic syndrome including weight gain and insulin resistance.
Polysorbate 80 and carboxymethylcellulose each independently disrupted intestinal epithelial integrity when interacting with human gut microbiota in an in vitro model, with polysorbate 80 showing the stronger effect on barrier function.
Maternal dietary exposure to polysorbate 80 in mice produced gut dysbiosis in offspring, and those offspring showed increased susceptibility to colitis in adulthood.
Muscle metabolism and systemic effects
A 2020 mouse study found that polysorbate 80-induced disruption of the gut barrier allowed bacterial products to reach the bloodstream, and this was associated with impaired skeletal muscle metabolism. The study authors described a gut-to-muscle signalling axis, though the findings come entirely from rodent models.
Polysorbate 80-induced intestinal permeability in mice was associated with impaired skeletal muscle lipid oxidation and altered metabolic function, suggesting gut-to-muscle crosstalk mediated by endotoxaemia.
Regulatory safety review
The European Food Safety Authority completed a group re-evaluation of polysorbates (E432 to E436) in 2015 and set a group acceptable daily intake of 25 milligrams per kilogram of body weight per day, based on long-term rat studies. The authority noted that estimated dietary exposure from approved uses stayed within this limit for most people. However, the Chassaing 2015 gut microbiome study was published the same year as the EFSA opinion and was not fully considered in that review. The UK FSA maintains the same approval under assimilated EU law.
EFSA ANS Panel set a group ADI of 25 mg/kg bw/day for polysorbates E432 to E436, derived from a NOAEL of 2,500 mg/kg bw/day in long-term rat carcinogenicity studies with a 100-fold uncertainty factor.
Where it stands with the regulators
Who should be careful
People with inflammatory bowel disease (Crohn's disease or ulcerative colitis) may want to monitor their intake given the animal data on gut inflammation, and some gastroenterologists advise caution. Look for 'emulsifier: E433' or 'emulsifier: polysorbate 80' on the ingredients list.
The honest read
The animal data on polysorbate 80 is genuinely striking because it used concentrations intended to reflect real-world dietary exposure, not the massive overdose levels that characterise weaker food additive studies. However, mice are not people: their gut architecture and microbiome differ, and no controlled human trial has yet reproduced the colitis or metabolic syndrome findings. Observational studies in humans suggest associations between high processed-food consumption and bowel inflammation, but isolating polysorbate 80 as a driver from a complex diet is not straightforward. Regulators reviewed the evidence in 2015, before much of the recent microbiome research accumulated, and no restriction has followed. This is an area where the science is moving faster than the regulation, and the picture is not resolved.
Related additives
Common questions
Is E433 banned in the UK?
No. E433 (polysorbate 80) is approved for use in the UK under the assimilated EU Regulation 1333/2008. It is listed on the UK FSA's approved additives register.
What did the Chassaing 2015 study actually find?
A Nature-published mouse study by Chassaing and colleagues found that polysorbate 80 in drinking water eroded the gut's protective mucus layer, disrupted gut bacteria, and caused low-grade inflammation and metabolic changes in healthy mice. In mice prone to bowel disease it triggered colitis. The doses used were intended to approximate human dietary intake from processed foods, though the translation to people has not been confirmed in controlled trials.
What foods contain E433?
Ice cream, frozen desserts, salad dressings, mayonnaise, cakes, whipped cream, chocolate-coated products, low-fat spreads, and some vitamin and dietary supplements. On the label it appears as 'emulsifier: polysorbate 80' or 'emulsifier: E433'.
Is E433 vegan?
The oleic acid in polysorbate 80 is most commonly derived from plant oils (typically sunflower or soybean), making most commercial food-grade polysorbate 80 vegan. However, the source of the fatty acid is not declared on the label, so strict vegans may wish to contact the manufacturer directly.
Sources
- UK FSA Regulated Products Register: E433
- UK Food Standards Agency: Approved Additives and E Numbers
- EFSA Scientific Opinion on re-evaluation of polysorbates E432-E436, EFSA Journal 2015;13(7):4152
- Chassaing B et al. Dietary emulsifiers impact the mouse gut microbiota promoting colitis and metabolic syndrome. Nature, 2015
- Polysorbate 80-induced leaky gut impairs skeletal muscle metabolism in mice. PubMed PMID 33113283
- Maternal Emulsifier P80 Intake Induces Gut Dysbiosis in Offspring and Increases Their Susceptibility to Colitis in Adulthood. PMC8547008
- Polysorbate 80 and carboxymethylcellulose: A different impact on epithelial integrity when interacting with the microbiome. ScienceDirect 2025
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