COMPARISON BETWEEN EXTRA VIRGIN OLIVE OIL AND OLEIC-ACID RICH SUNFLOWER OIL - EFFECTS ON POSTPRANDIAL LIPEMIA AND LDL SUSCEPTIBILITY TO OXIDATION

The aim of our study was to determine whether the minor polar componen ts of virgin olive oil could have favorable effects (1) on fasting and postprandial lipid profile and (2) on low-density lipoprotein (LDL) c omposition and susceptibility to oxidation in vitro. Ten normolipidic subjects were included in a crossover study (two diet periods of 3 wee ks) and received either virgin olive oil (OO diet) or oleic acid rich sunflower oil. An oral fat load was performed at the end of each perio d. The plasma lipid levels were not significantly different after both diets in the fasting and postprandial states. A few minor variations of the LDL composition were observed only in the postprandial lipemia, and they were different after both diets. The LDL oxidation susceptib ility was evaluated by the formation of conjugated dienes. With LDL is olated in the fasting state, the diene production decreased (p = 0.057 3) only after the OO diet. The dienes determined at time O and the max imal dienes obtained during the oxidation reaction decreased (p = 0.01 45 and p = 0.0184, respectively) only after the OO fat load. Neverthel ess, the diene production decrease was not significant (p = 0.0848), O ur results suggest a mild effect of minor components of virgin olive o il related to a decrease of LDL susceptibility to oxidation; further a nalyses are necessary to give clear conclusions about their role.