Supplementation of postmenopausal women with fish oil does not increase ex vivo oxidation of LDL comparted to dietary oils rich in oleate and linoleate

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Rosemary Wander (Creator)
Institution
The University of North Carolina at Greensboro (UNCG )
Web Site: http://library.uncg.edu/

Abstract: Abstract: Although replacement of dietary saturated fat with monounsaturated and polyunsaturated fatty acids (MUFA and PUFA) has been advocated for the reduction of cardiovascular disease risk, diets high in PUFA could increase low density lipoprotein (LDL) susceptibility to oxidation, potentially contributing to the pathology of atherosclerosis. To investigate this possibility, 15 postmenopausal women in a blinded crossover trial consumed 15 g of sunflower oil (SU) providing 12.3 g/day of oleate, safflower oil (SA) providing 10.5 g/day of linoleate, and fish oil (FO) providing 2.0 g/day of eicosapentaenoate (EPA) and 1.4 g/day of docosahexaenoate (DHA). During CuSO4- mediated oxidation, LDL was depleted of ot-tocopherol more rapidly after FO supplementation than after supplementation with SU (P = 0.0001) and SA (P = 0.05). In LDL phospholipid and cholesteryl ester fractions, loss of n-3 PUFA was greater and loss of n-6 PUFA less after FO supplementation than after SU and SA supplementation (P < 0.05 for all), but loss of total PUFA did not differ. The lag phase for phosphatidylcholine hydroperoxide (PCOOH) formation was shorter after FO supplementation than after supplementation with SU (P = 0.0001) and SA (P = 0.006), whereas the lag phase for cholesteryl linoleate hydroperoxide (CE18:2OOH) formation was shorter after FO supplementation than after SU (P = 0.03) but not SA. In contrast, maximal rates of PCOOH and CE18:2OOH formation were lower after FO supplementation than after SA (P = 0.02 and 0.0001, respectively) and maximal concentrations of PCOOH and CE18:2OOH were lower after FO supplementation than after SA (P = 0.03 and 0.0006, respectively). Taken together, our results suggest that FO supplementation does not increase the overall oxidation of LDL ex vivo, especially when compared with SA supplemen-tation. Consequently, health benefits related to increased fish consumption may not be offset by increased LDL oxidative susceptibility.—Higdon, J. V., S. H. Du, Y. S. Lee, T. Wu, and R. C. Wander. Supplementation of postmenopausal women with fish oil does not increase overall oxidation of LDL ex vivo compared to dietary oils rich in oleate and linoleate.

Additional Information

Publication
Journal of Lipid Research. 42:407-418
Language: English
Date: 2001
Keywords
lipid peroxidation, lipid hydroperoxides, monounsaturated fatty acids, polyunsaturated fatty acids, n-3 fatty acids, n-6 fatty acids, alpha tocopherol