POSTPRANDIAL CHANGES IN PLATELET-FUNCTION AND COAGULATION-FACTORS AFTER HIGH-FAT MEALS WITH DIFFERENT FATTY-ACID COMPOSITIONS

Objective: To compare the postprandial effects of three oils differing in their fatty acid composition on platelet aggregation and coagulation. The oils studied were low-erucic acid rapeseed oil (RO, oleic acid 54% of fatty acids), sunflower oil (SO, linoleic acid 64% of fatty acids) and butter oil (BO, saturated fatty acids 62% of fatty acids). Design: The postprandial effects of three fat-loads were followed for 5 h. Setting: Division of Nutrition, University of Helsinki. Subjects: Twelve healthy female subjects (aged 23-38 years) were recruited among university students and employees. Interventions: Postprandial lipaemia was induced by high-fat meals containing fat (RO, SO or BO) 1 g/kg of body weight, skim-milk powder, sugar, strawberries, and water. Each subject ingested each meal in three separate mornings after an overnight fast. The order of the meals was randomised. Blood samples were taken before and 1, 2.5, and 5h after the test meal. Results: All three test meals similarly affected platelet aggregation in platelet-rich plasma. Aggregation induced by collagen (0.6, 1 acid 2.5 mu g/ml) decreased during the 5-h period after the meals (P = 0.000). ADP-induced aggregation did not change during the follow-up period after any meal (P = 0.105-0.483). All fat loads increased factor VII coagulant activity (F VII:C) (P = 0.000), but in plasma fibrinogen concentration (P = 0.155) or antithrombin III activity (P = 0.278) no postprandial changes were found. Conclusions: These results show that high-fat meals have acute effects on platelet function and F VII:C in healthy women and that these effects are not mediated through the fatty acid composition of the meals.