Effects of fish oil- and olive oil-rich diets on iron metabolism and oxidative stress in the rat

• Published in: British journal of nutrition 2003-01, Vol.89 (1), p.11-18
• Main Authors: Miret, S., Sáiz, M. P., Mitjavila, M. T.
• Format: Article
• Language: English
• Subjects: alpha-tocopherol; Animals; Antioxidants; Biological and medical sciences; corn oil; Diet; Dietary Fats, Unsaturated - pharmacology; Erythrocytes; Fatty acids; Feeding. Feeding behavior; Fish oils; Fish Oils - pharmacology; Fundamental and applied biological sciences. Psychology; glutathione peroxidase; iron; Iron - metabolism; Lipid peroxidation; Lipid Peroxidation - drug effects; Lipids; Liver; Liver - metabolism; Male; Metabolism; mineral metabolism; Nutrition research; Olive Oil; Oxidation; Oxidative stress; Oxidative Stress - drug effects; Peroxidation; Plant Oils - pharmacology; Plasma; Rats; Rats, Sprague-Dawley; Spleen; Spleen - metabolism; superoxide dismutase; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Vitamin E
• ISSN: 0007-1145; 1475-2662
• DOI: 10.1079/BJN2002737

The objective of the present study was to examine the effects of fish oil (FO)- and olive oil (OO)-rich diets on Fe metabolism and oxidative stress. Rats were fed for 16 weeks with diets containing 50 g lipid/g; either OO, maize oil (MO) or FO. OO or MO diets contained a standard amount (100 m/g) of all-rac-α-tocopheryl acetate. FO diets were supplemented with 0, 100 or 200 mg all-rac-α-tocopheryl acetat/g (FO-0, FO-1 or FO-2 diets, respectively). At the end of the feeding period, we measured non-haem Fe stores in liver and spleen, and erythrocyte and reticulocyte count. We also determined antioxidants and products derived from lipid peroxidation in plasma and erythrocytes. Our results showed reduced non-haem Fe stores in rats fed any of the FO diets. Reticulocyte percentage was higher in the rats fed FO-0 and FO-1. Plasma α-tocopherol was very low in rats fed the FO-0 diet. Rats fed the FO-1 and FO-2 diets showed higher α-tocopherol in plasma than the FO-0 group but lower than the MO or OO groups. We did not observe such differences in the α-tocopherol content in erythrocyte membranes. Superoxide dismutase and glutathione peroxidase activities were lower in the erythrocytes of rats fed the FO-0 diet. The products derived from lipid peroxidation were also higher in the FO groups. The administration of FO-rich diets increased lipid peroxidation and affected Fe metabolism. On the other hand, the OO-rich diet did not increase oxidative stress and did not alter Fe metabolism. Based on these results, we conclude that FO supplementation should be advised carefully.