Effects of fish oil fatty acids on plasma lipids and lipoproteins and oxidant-antioxidant imbalance in healthy subjects

Abstract

The purpose of this study was to investigate the effect of eicosapentaenoic and docosahexaenoic acids on plasma lipids and lipoproteins, lipid peroxidation and antioxidant status in healthy humans. A total of 19 healthy volunteers consumed 6 g/day Maxepa fish oil for 3 weeks (1.8 g n-3 fatty acids/day). At baseline and at day 21, we evaluated plasma lipoproteins, plasma and low-density lipoprotein fatty acids, lipid peroxidation markers (malondialdehyde concentration, low-density lipoprotein peroxidation in vitro), and the content of a number of antioxidants (reduced and oxidized glutathione in whole blood, plasma and erythrocyte glutathione peroxidases, plasma vitamin E and beta carotene). Plasma concentrations of total cholesterol, triglycerides, phospholipids, low-density lipoprotein cholesterol and low-density lipoprotein size did not differ significantly after 3 weeks of supplementation. Adding the fish oil to the diet increased the concentration of n-3 very-long-chain polyunsaturated fatty acids and decreased the concentration of n-6 fatty acid and oleic acid in plasma and low-density lipoprotein. Eicosapentaenoic and docosahexaenoic acid supplementation caused elevated values of the high-density lipoprotein cholesterol due to an increment of the high-density lipoprotein 2 fraction and reduced low-density lipoprotein peroxidation rate in vitro. However, we observed an imbalance between oxidizable substrates and antioxidants with an increased lipid peroxidation, whereas the content of reduced glutathione and beta carotene decreased without any variation in vitamin E. Association of antioxidants with n-3 PUFA could prevent lipid peroxidation and enhance the antiatherogenic effects of n-3 polyunsaturated fatty acids.

Effects of Lutein and Docosahexaenoic Acid Supplementation on Macular Pigment Optical Density in a Randomized Controlled Trial

“…Moreover, in two prospective follow-up studies it was reported that DHA intake was inversely related to the risk of AMD [3,16]. Of note is the observation that supplemental DHA increases HDL and HDL subfractions in serum [17,18,19]. Given that the carotenoids transport is made by lipids (HDL) [20,21], DHA supplementation could increase its transport to the retina and subsequently cause a MP ocular density (MPOD) increase.…”

Reactive Oxygen Species and Acute Modulation of Albumin Microvascular Leakage in the Microcirculation of Diabetic Rats in vivo

“…It has also been demonstrated to be implicated in decreased endothelium-dependent dilating capacity associated with hyperglycemia or diabetes [9]. Another aspect in which oxidative mechanisms could potentially be involved is the generalized increase in transvascular passage of macromolecules [10]described in different types of diabetes in animals [11]and also found in patients [12, 13]even at very early stages of the disease [14]. Indeed, several mechanisms have been proposed to explain this increase in transvascular passage of macromolecules associated with diabetes.…”