Olestra vs Polysorbate 80: which is worse?

What is Olestra?

Olestra (brand name Olean) is a synthetic fat substitute made from sucrose and fatty acids. Unlike regular fats, olestra is not absorbed by the digestive system — it passes through the body unchanged, providing zero calories while mimicking fat's texture and taste in food. It was developed by Procter & Gamble and FDA-approved in 1996.

What is Polysorbate 80?

Polysorbate 80 (Tween 80) is a synthetic nonionic surfactant and emulsifier derived from sorbitol and oleic acid (from vegetable oils) through ethoxylation. It is widely used in food to keep water-based and oil-based ingredients uniformly mixed. Chemical formula: polyoxyethylene (20) sorbitan monooleate.

Documented risks

Olestra: Olestra caused significant gastrointestinal side effects that were prominently noted on mandatory warning labels: 'This Product Contains Olestra. Olestra may cause abdominal cramping and loose stools. Olestra inhibits the absorption of some vitamins and other nutrients. Vitamins A, D, E, and K have been added.' Reported gastrointestinal effects included diarrhea, abdominal cramping, oily anal leakage ('anal leakage' or 'rectal leakage'), and fatty stools. These effects were often embarrassing and uncomfortable. Multiple consumer complaints documented GI distress from Olean chips. Beyond GI effects, olestra significantly inhibits the absorption of fat-soluble vitamins (A, D, E, K) and fat-soluble carotenoids (lycopene, lutein, beta-carotene). Since fat-soluble vitamins require fat for absorption, and olestra passes through without being absorbed, it 'captures' these vitamins and carries them out of the body. Studies found olestra consumption reduced serum carotenoid levels, prompting Frito-Lay to fortify olestra products with fat-soluble vitamins to compensate. The FDA removed the mandatory GI warning requirement in 2003 after Frito-Lay argued the warning was overstated, though olestra's use had already declined dramatically due to consumer avoidance.

Polysorbate 80: Emerging research has raised concerns about polysorbate 80's effects on the gut. A landmark 2015 study in Nature (Chassaing et al.) found that dietary polysorbate 80 and polysorbate 60 at concentrations approaching food use levels promoted colitis and metabolic syndrome in genetically susceptible mice by disrupting the intestinal mucus layer and altering gut microbiome composition. The emulsifiers thinned the protective mucus layer, allowing bacteria to come into closer contact with gut epithelial cells and triggering inflammation. This study was a seminal contribution to gut health research, though it was conducted in mice and requires confirmation in humans. A 2020 follow-up study found that dietary emulsifiers including polysorbate 80 promoted gut inflammation and altered gut microbiome in human participants with Crohn's disease. People with inflammatory bowel disease may be most vulnerable to polysorbate 80's potential gut effects.