Summary
This double-blind, cross-over study with olive oil as placebo, examined the effect
of a daily dosage of 6 g fish oil on cardiovascular risk markers of 20 healthy young
volunteers (10 men, 10 women). Serum lipids and lipoproteins, and plasma coagulation
and fibrinolytic enzymes, including fibrinogen concentrations and plasminogen activator
inhibitor-1 (PAI-1) activity were measured at baseline and after 6-week supplementation
of either fish or olive oil. The results showed that fish oil had an independent lowering
effect on triglycerides and coagulation factors Vc and VIIc. Both fish and olive oil
significantly raised PAI-1 levels and lowered plasma factor Xc and fibrinogen levels
in the women, who had higher initial levels than the men. Mean fibrinogen levels of
the women were lowered from 3.23 ± 0.98 to 2.64 ± 0.55 g/1 and from 3.19 ± 0.72 to
2.66 ± 0.49 g/1 by fish and olive oil respectively. This study raises the question
whether a particular fatty acid or group of fatty acids, or another constituent of
the oil such as vitamin E may be responsible for the fibrinogen lowering effect.
