DIETARY FATTY-ACIDS, MEMBRANE-TRANSPORT, AND OXIDATIVE SENSITIVITY INHUMAN ERYTHROCYTES

This study examined effects of dietary n-3 fatty acids on age-related changes in erythrocyte anion transport and susceptibility to oxidation . Blood was drawn from healthy adult volunteers before and after six w eeks' supplementation (nine/group) with 4.0 g/day of safflower oil (co ntaining 2.9 g n-6 fatty acids) or fish oil (containing 1.2 g long-cha in n-3 fatty acids). Following density separation of young and old ery throcytes, membrane anion transport and cell membrane lipid compositio n were measured. Oxidative damage was measured in erythrocyte ghosts e xposed to a free radical generator. Fish oil significantly increased 1 6:0 and 20:5n-3 in ghosts of both young and old cells, and 22:5n-3 and 22:6n-3 in old cells alone, Safflower oil increased 16:0, 18:0, 18:1n -9, and 22:5n-6 in ghosts of young cells only. The age-dependent incre ase in membrane anion transport (P < 0.01) was decreased by dietary fi sh oil supplementation, but not by safflower oil supplementation. Saff lower oil and fish oil increased the susceptibility of both young and old erythrocytes to oxidative damage by free radical generation (P < 0 .001).