Butylated Hydroxytoluene vs Polysorbate 80: which is worse?

What is Butylated Hydroxytoluene?

Butylated hydroxytoluene (BHT) is a synthetic lipophilic phenolic antioxidant preservative derived from petroleum. It is a white crystalline solid with chemical formula C15H24O. Like BHA, it prevents fat oxidation and is widely used in food, cosmetics, pharmaceuticals, jet fuel, and rubber.

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

Butylated Hydroxytoluene: BHT's carcinogenicity profile is complex and bidirectional. Some NTP bioassays found liver tumors in female mice at high doses, while other studies suggested BHT might inhibit tumor initiation in certain contexts. A 1986 NTP bioassay found liver tumors in female mice but anti-carcinogenic effects in the rat forestomach — making BHT's net carcinogenicity uncertain. IARC has not formally classified BHT in a specific Group due to this conflicting evidence. The NTP notes that BHT's carcinogenicity data are complex. The 'Report on Carcinogens' does not currently list BHT, unlike BHA, but the NTP has noted inconclusive evidence. Potential endocrine disruption: a 2017 study in Environmental Science & Technology found BHT disrupted thyroid hormone levels in female rats. Multiple animal studies have demonstrated weak estrogenic effects. The American Academy of Pediatrics' 2018 policy statement on food additives mentioned BHT as a synthetic preservative warranting reduced childhood exposure. Kellogg's Frosted Flakes in the US contains BHT to preserve freshness; the European version uses mixed tocopherols (vitamin E) instead — a commercially meaningful difference demonstrating feasibility of substitution. Japan banned BHT for food use based on its precautionary approach. The EU restricts it with ADI-based maximum permitted levels.

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.