The Effects of Olive Oil, Hydrogenated Palm Oil, and co-3 Fatty Acid-Enriched Diets on Megakaryocytes and Platelets

Unsaturated fatty acids are thought to pi event 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 welll understood. We compared the effects of diets enriched with 8.4% olive oil, 8.4% hydrogenated palm oil, or 10.2% to-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 megakaryocyi:es, 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 w-3 fatty acid-enriched diet: 12.9± 1.78x 10 compared with 7.45±1.08xl0 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 to-3 fatty acid-enriched diet but not with the other diets. The to-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 athero|>enic, this diet had no affect on platelet function. The possibility that olive oil-enriched diets can increase platelet sensitivity and thereby augment thrombosis should be considered when making recommendations for increasing the dietary intake of monounsaturated fatty acids. (Arteriosclerosis and Thrombosis 1993;13:84-89)