title: Oxidised fish oil does not influence established markers of oxidative stress in healthy human subjects: a randomised controlled trial.
abstract: Intake of fish oil reduces the risk of CHD and CHD deaths. Marine n-3 fatty acids (FA) are susceptible to oxidation, but to our knowledge, the health effects of intake of oxidised fish oil have not previously been investigated in human subjects. The aim of the present study was to investigate markers of oxidative stress, lipid peroxidation and inflammation, and the level of plasma n-3 FA after intake of oxidised fish oil. In a double-blinded randomised controlled study, healthy subjects (aged 18-50 years, n 54) were assigned into one of three groups receiving capsules containing either 8 g/d of fish oil (1.6 g/d EPA+DHA; n 17), 8 g/d of oxidised fish oil (1.6 g/d EPA+DHA; n 18) or 8 g/d of high-oleic sunflower oil (n 19). Fasting blood and morning spot urine samples were collected at weeks 0, 3 and 7. No significant changes between the different groups were observed with regard to urinary 8-iso-PGF2α; plasma levels of 4-hydroxy-2-hexenal, 4-hydroxy-2-nonenal and α-tocopherol; serum high sensitive C-reactive protein; or activity of antioxidant enzymes in erythrocytes. A significant increase in plasma level of EPA+DHA was observed in both fish oil groups, but no significant difference was observed between the fish oil groups. No changes in a variety of in vivo markers of oxidative stress, lipid peroxidation or inflammation were observed after daily intake of oxidised fish oil for 3 or 7 weeks, indicating that intake of oxidised fish oil may not have unfavourable short-term effects in healthy human subjects.
authors.affiliation: Faculty of Health, Nutrition and Management, Akershus University College, Lillestrøm, Norway.
authors.forename: Inger
authors.initials: I
authors.lastname: Ottestad
authors.forename: Gjermund
authors.initials: G
authors.lastname: Vogt
authors.forename: Kjetil
authors.initials: K
authors.lastname: Retterstøl
authors.forename: Mari C
authors.initials: MC
authors.lastname: Myhrstad
authors.forename: John-Erik
authors.initials: JE
authors.lastname: Haugen
authors.forename: Astrid
authors.initials: A
authors.lastname: Nilsson
authors.forename: Gitte
authors.initials: G
authors.lastname: Ravn-Haren
authors.forename: Berit
authors.initials: B
authors.lastname: Nordvi
authors.forename: Kirsti W
authors.initials: KW
authors.lastname: Brønner
authors.forename: Lene F
authors.initials: LF
authors.lastname: Andersen
authors.forename: Kirsten B
authors.initials: KB
authors.lastname: Holven
authors.forename: Stine M
authors.initials: SM
authors.lastname: Ulven
mesh_terms: D000328:Adult; D000447:Aldehydes / Q000097:blood; D015415:Biomarkers / Q000097:blood / Q000652:urine; D002097:C-Reactive Protein / Q000032:analysis; D003060:Cod Liver Oil / Q000009:adverse effects* / Q000737:chemistry*; D019587:Dietary Supplements / Q000009:adverse effects* / Q000032:analysis*; D015237:Dinoprost / Q000031:analogs & derivatives / Q000652:urine; D004311:Double-Blind Method; D004912:Erythrocytes / Q000201:enzymology; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage / Q000097:blood; D005260:Female; D006801:Humans; D015227:Lipid Peroxidation; D008297:Male; D009664:Norway; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010088:Oxidoreductases / Q000097:blood; D010352:Patient Dropouts; D055815:Young Adult; D024502:alpha-Tocopherol / Q000097:blood
chemical_list: D000447:Aldehydes; D015415:Biomarkers; D015525:Fatty Acids, Omega-3; C045934:4-hydroxy-2-hexenal; C075750:8-epi-prostaglandin F2alpha; D003060:Cod Liver Oil; D002097:C-Reactive Protein; D015237:Dinoprost; D010088:Oxidoreductases; D024502:alpha-Tocopherol; C027576:4-hydroxy-2-nonenal