The effects of olive oil, hydrogenated palm oil, and omega-3 fatty acid-enriched diets on megakaryocytes and platelets.

Unsaturated fatty acids are thought to prevent thrombotic and arteriosclerotic disease, whereas saturated fatty acids are thought to increase the incidence of these disorders. However, the effects of these diets on megakaryocytes and platelets are not well understood. We compared the effects of diets enriched with 8.4% olive oil, 8.4% hydrogenated palm oil, or 10.2% omega-3 fatty acid ethyl esters on guinea pig megakaryocytes and platelets. In plasma, changes in fatty acid composition reflected the composition of each diet. However, in platelets and megakaryocytes, hydrogenated palm oil induced a decrease in 16:0 and an increase in 18:2 while the olive oil diet caused a marked increase in 18:1 and a decrease in most other fatty acids. The differences in the effects of the diets on cellular versus plasma fatty acids suggest that megakaryocytes and platelets have an extensive capacity to regulate their fatty acid composition. Thrombocytosis occurred with the omega-3 fatty acid-enriched diet: 12.9 +/- 1.78 x 10(5) compared with 7.45 +/- 1.08 x 10(5) platelets per microliter of platelet-rich plasma in control animals. There was an increase in megakaryocyte size, ploidy, and morphological stage (cytoplasmic maturation) with the omega-3 fatty acid-enriched diet but not with the other diets. The omega-3 fatty acid-enriched diet decreased platelet thromboxane production while the other diets had no effect. Platelet hypersensitivity was suggested in collagen aggregation studies with olive oil but not with the hydrogenated palm oil diet. Although saturated fatty acid diets are thought to be atherogenic, this diet had no affect on platelet function.(ABSTRACT TRUNCATED AT 250 WORDS)