title: Paradoxical effect of n-3-containing vegetable oils on long-chain n-3 fatty acids in rat heart.
abstract: Flaxseed, echium, and canola oils contain alpha-linolenic acid (18:3n-3, ALA) in a range of concentrations. To examine their effect on elevating cardiac levels of long-chain n-3 FA, diets based on these n-3-containing vegetable oils were fed to rats for 4 wk. Sunflower oil, which contains little ALA, was a comparator. Despite canola oil having the lowest ALA content of the three n-3-containing vegetable oils, it was the most potent for elevating DHA (22:6n-3) levels in rat hearts and plasma. However, the relative potencies of the dietary oils for elevation of EPA (20:5n-3) in heart and plasma followed the same rank order as their ALA content, i.e., flaxseed > echium > canola > sunflower oil. This paradox may be explained by lower ALA intake leading to decreased competition for Delta6 desaturase activity between ALA and the 24:5n-3 FA precursor to DHA formation.
authors.affiliation: Hanson Institute and Rheumatology Unit, Royal Adelaide Hospital, SA, Australia.
authors.forename: Leslie G
authors.initials: LG
authors.lastname: Cleland
authors.forename: Robert A
authors.initials: RA
authors.lastname: Gibson
authors.forename: Janet
authors.initials: J
authors.lastname: Pedler
authors.forename: Michael J
authors.initials: MJ
authors.lastname: James
mesh_terms: D000818:Animals; D016718:Arachidonic Acid / Q000097:blood / Q000378:metabolism; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D004281:Docosahexaenoic Acids / Q000097:blood / Q000378:metabolism; D015118:Eicosapentaenoic Acid / Q000097:blood / Q000378:metabolism; D005227:Fatty Acids / Q000032:analysis / Q000378:metabolism; D015525:Fatty Acids, Omega-3 / Q000097:blood / Q000378:metabolism* / Q000494:pharmacology; D043371:Fatty Acids, Omega-6 / Q000097:blood / Q000378:metabolism; D005231:Fatty Acids, Unsaturated / Q000097:blood / Q000378:metabolism; D005260:Female; D006321:Heart / Q000187:drug effects; D009206:Myocardium / Q000737:chemistry / Q000378:metabolism*; D010743:Phospholipids / Q000737:chemistry / Q000378:metabolism; D010938:Plant Oils / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D051381:Rats; D017962:alpha-Linolenic Acid / Q000032:analysis / Q000378:metabolism / Q000494:pharmacology
chemical_list: D004042:Dietary Fats, Unsaturated; D005227:Fatty Acids; D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6; D005231:Fatty Acids, Unsaturated; D010743:Phospholipids; D010938:Plant Oils; D017962:alpha-Linolenic Acid; D004281:Docosahexaenoic Acids; D016718:Arachidonic Acid; D015118:Eicosapentaenoic Acid; C026219:docosapentaenoic acid