title: Consumption of thermally-oxidized sunflower oil by chicks reduces alpha-tocopherol status and increases susceptibility of tissues to lipid oxidation.
abstract: The effect of heated sunflower oil consumption on alpha-tocopherol status, fatty acid composition and oxidative stability of chicken tissues was investigated. Chicks were fed on diets containing (g/kg): fresh sunflower oil (FSO) 40, heated sunflower oil (HSO) 40 or heated sunflower oil (40) supplemented with alpha-tocopheryl acetate (HSE) to a similar alpha-tocopherol concentration as the FSO diet. Concentrations of alpha-tocopherol in tissues of chicks fed on HSO and HSE were significantly lower than those of chicks fed on FSO. Significant correlations were observed between plasma alpha-tocopherol concentration and the alpha-tocopherol concentrations of other tissues (r > or = 0.67, P < 0.005) and between log plasma alpha-tocopherol and plasma thiobarbituric acid-reacting substances (TBARS) concentrations (r -0.851, P < 0.001). The concentrations of TBARS in tissues of chicks fed on the various diets were generally very similar before stimulation of peroxidation with Fe-ascorbate. Susceptibility of tissues to Fe-ascorbate-induced lipid peroxidation was increased by feeding HSO. Supplementation with alpha-tocopheryl acetate reduced susceptibility to lipid oxidation to varying degrees, depending on the tissue. The results suggest that chronic ingestion of oxidized lipids may compromise free-radical-scavenging activity in vivo by depleting alpha-tocopherol in the gastrointestinal tract, or possibly in plasma and other tissues.
authors.affiliation: Department of Nutrition, University College, Cork, Republic of Ireland.
authors.forename: P J
authors.initials: PJ
authors.lastname: Sheehy
authors.forename: P A
authors.initials: PA
authors.lastname: Morrissey
authors.forename: A
authors.initials: A
authors.lastname: Flynn
mesh_terms: D000818:Animals; D001205:Ascorbic Acid / Q000494:pharmacology; D001823:Body Composition / Q000187:drug effects; D001835:Body Weight / Q000502:physiology; D002645:Chickens / Q000378:metabolism*; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage*; D005227:Fatty Acids / Q000378:metabolism; D005260:Female; D005290:Ferric Compounds / Q000494:pharmacology; D006368:Helianthus; D006358:Hot Temperature / Q000009:adverse effects*; D015227:Lipid Peroxidation / Q000187:drug effects / Q000502:physiology*; D009752:Nutritional Status; D010938:Plant Oils / Q000008:administration & dosage*; D000074242:Sunflower Oil; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D024505:Tocopherols; D014810:Vitamin E / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000097:blood / Q000378:metabolism*; D024502:alpha-Tocopherol / Q000031:analogs & derivatives*
chemical_list: D004042:Dietary Fats, Unsaturated; D005227:Fatty Acids; D005290:Ferric Compounds; D010938:Plant Oils; D000074242:Sunflower Oil; D017392:Thiobarbituric Acid Reactive Substances; D014810:Vitamin E; C061126:iron(III)-ascorbic acid complex; D024502:alpha-Tocopherol; D001205:Ascorbic Acid; D024505:Tocopherols