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).