Twenty healthy male volunteers were randomly assigned to receive either four 1-g capsules
of n-3 polyunsaturated fatty acids (PUFA) ethyl esters or four 1-g capsules of olive
oil (as placebo) for a period of 4 months, followed by a 3-month wash-out period.
Fatty acids of platelet phospholipid fractions, platelet aggregation, and thromboxane
B2 (TXB2) formation were analyzed at 0, 2, and 4 months of treatment and at 1, 2,
and 3 months of wash-out. During n-3 PUFA supplementation, accumulations of eicosapentaenoic
(EPA), docosapentaenoic (DPA), and docosahexaenoic (DHA) acids were markedly increased
after 2 months, with slight differences in further accumulation up to 4 months among
the various phospholipid fractions. Significant decreases in platelet sensitivity
to collagen, serum TXB2 levels, and urinary TXB2 metabolites were also observed following
n-3 PUFA treatment. During the first and second month of wash-out, slight differences
were observed in changes of various fatty acids among different phospholipid fractions,
but after 3 months of wash-out, alterations were no longer detectable with respect
to pretreatment values. After 3 months of wash-out, platelet function parameters also
were returned to baseline. Thus, both platelet lipids and function are influenced
by n-3 PUFA ethyl ester supplementation, and significant alterations are still detectable
after 2 months of wash-out.