Polysorbate 80 vs Saccharin: which is worse?

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.

What is Saccharin?

Saccharin is the oldest artificial sweetener, discovered accidentally at Johns Hopkins in 1879. It is a sulfonamide compound approximately 300-400 times sweeter than sucrose with no caloric value. It has a slightly bitter metallic aftertaste at higher concentrations. Saccharin's sodium salt (sodium saccharin) is the form used in most food applications.

Documented risks

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.

Saccharin: Saccharin's carcinogenicity history is one of the most tumultuous in food regulatory history. In 1977, the FDA proposed banning saccharin after studies found it caused bladder cancer in rats at very high doses. Congress passed the Saccharin Study and Labeling Act, which put a moratorium on the ban and required a cancer warning label on saccharin products ('Use of this product may be hazardous to your health. This product contains saccharin which has been determined to cause cancer in laboratory animals.'). By 2000, saccharin was removed from the US National Toxicology Program's Report on Carcinogens after subsequent research determined that the bladder cancer in male rats was caused by a rat-specific mechanism — high pH, high protein, and calcium phosphate in rat urine — that does not apply to human urine. The cancer warning label requirement was repealed. IARC also removed saccharin from its Group 2B list in 1999. However, Canada maintained its ban on food use saccharin, citing continued precautionary concern. A 2022 study in Cell found saccharin was among the artificial sweeteners most significantly altering gut microbiome composition and glucose tolerance in previously non-sweetener-using participants. Saccharin showed the largest effect on glucose tolerance among the sweeteners studied (saccharin, sucralose, aspartame, stevia). Saccharin passes through the placenta and appears in breast milk, raising questions about infant exposure that have not been fully resolved.