Effect of dietary olive and sunflower oils on the lipid composition of the aorta and platelets and on blood eicosanoids in rats.

The effects on aortic and platelet fatty acid compositions and on blood levels of prostacyclin and thromboxane A2 of low- and high-fat diets containing olive oil or sunflower oil were studied. For 4 weeks, four groups of weanling rats were fed a basal diet containing 5% or 25% olive oil or sunflower oil. Rats fed olive oil diets showed higher levels of 18:1(n-9) and polyunsaturated fatty acids of the n-3 series and lower percentages of 18:0 and 18:2(n-6) in aortic and platelet phosphatidylcholine and phosphatidylethanolamine than those fed the sunflower oil diets. Arachidonic acid increased in platelet phosphatidylethanolamine and aortic phosphatidylcholine of rats fed the diet containing 5% sunflower oil compared with those fed 5% olive oil. Plasma 6-ketoprostaglandin F1 alpha increased in both groups of animals fed olive oil while these rats also showed the lowest levels of serum thromboxane B2 and plasma cholesterol. Olive oil feeding leads to changes in lipid metabolism of the vascular compartment that could be favorable in the prevention of thrombosis and atherosclerosis.