title: Safety evaluation of phytosterol esters. Part 8. Lack of genotoxicity and subchronic toxicity with phytosterol oxides.
abstract: Vegetable oil spreads containing phytosterol-esters are marketed as a cholesterol-lowering functional food in more than 20 countries worldwide. An extensive package of safety data has shown phytosterol-esters to be safe for human use. However, even though phytosterols are very stable molecules, oxidation may occur at low levels under extreme heating conditions, resulting in phytosterol oxides. As there is some suggestion of adverse biological effects in the literature for the related cholesterol oxidation products, safety data have been generated for phytosterol oxides. A phytosterol oxide concentrate (POC) was generated by prolonged heating of phytosterol-esters in the presence of oxygen. The genotoxicity and subchronic toxicity of this mixture was assessed in a series of in vitro genotoxicity assays (bacterial mutation, chromosome aberration and micronucleus) and a subchronic feeding study in the rat. Results showed that a phytosterol oxide concentrate containing approximately 30% phytosterol oxides did not possess genotoxic potential and no obvious evidence of toxicity when administered in the diet of the rat for 90 consecutive days. In the latter study, a NOEL was established at an estimated dietary level of phytosterol oxides of 128 mg/kg/day for males and 144 mg/kg/day for females. In conclusion, these materials have been shown to raise no obvious concerns for human safety.
authors.affiliation: Safety & Environmental Assurance Centre, Unilever Colworth, Sharnbrook, Bedford MK44 1LQ, UK. linda.lea@unilever.com
authors.forename: L J
authors.initials: LJ
authors.lastname: Lea
authors.forename: P A
authors.initials: PA
authors.lastname: Hepburn
authors.forename: A M
authors.initials: AM
authors.lastname: Wolfreys
authors.forename: P
authors.initials: P
authors.lastname: Baldrick
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002869:Chromosome Aberrations / Q000139:chemically induced*; D003257:Consumer Product Safety; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000187:drug effects; D004952:Esters; D005260:Female; D008297:Male; D015162:Micronucleus Tests; D009152:Mutagenicity Tests; D019055:No-Observed-Adverse-Effect Level; D010084:Oxidation-Reduction; D010087:Oxides / Q000633:toxicity*; D010840:Phytosterols / Q000633:toxicity*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D018570:Risk Assessment; D012486:Salmonella typhimurium / Q000187:drug effects; D018675:Toxicity Tests
chemical_list: D004952:Esters; D010087:Oxides; D010840:Phytosterols