Oxidised fish oil does not influence established markers of oxidative stress in healthy human subjects: a randomised controlled trial

• Published in: British journal of nutrition Vol. 108; no. 2; pp. 315 - 326
• Main Authors: Ottestad, Inger, Vogt, Gjermund, Retterstøl, Kjetil, Myhrstad, Mari C., Haugen, John-Erik, Nilsson, Astrid, Ravn-Haren, Gitte, Nordvi, Berit, Brønner, Kirsti W., Andersen, Lene F., Holven, Kirsten B., Ulven, Stine M.
• Format: Journal Article
• Language: English
• Published: Cambridge Cambridge University Press 28.07.2012
• Subjects: Adult; Aldehydes - blood; alpha-tocopherol; alpha-Tocopherol - blood; Biological and medical sciences; Biomarkers - blood; Biomarkers - urine; blood serum; C-reactive protein; C-Reactive Protein - analysis; Cardiovascular disease; Clinical outcomes; Cod Liver Oil - adverse effects; Cod Liver Oil - chemistry; Dietary Supplements - adverse effects; Dietary Supplements - analysis; Dinoprost - analogs & derivatives; Dinoprost - urine; Double-Blind Method; enzyme activity; erythrocytes; Erythrocytes - enzymology; fasting; Fatty Acids, Omega-3 - administration & dosage; Fatty Acids, Omega-3 - blood; Feeding. Feeding behavior; Female; Fish; fish consumption; Fish oils; Fundamental and applied biological sciences. Psychology; Helianthus; Humans; inflammation; Lipid Peroxidation; Male; Norway; Nutrition research; omega-3 fatty acids; oxidation; Oxidation-Reduction; Oxidative Stress; Oxidoreductases - blood; Patient Dropouts; Peroxidation; randomized clinical trials; Risk reduction; Sunflower oil; urine; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Young Adult; Human; Oxidative stress; Vertebrata; Mammalia; Healthy subject; n-3; Lipid peroxidation; Lipids; Marker; Oxidised oil; Fish oil; Peroxidation
• ISSN: 0007-1145; 1475-2662; 1475-2662
• DOI: 10.1017/S0007114511005484

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-PGF 2α ; 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.