[Effects of dietary oil (olive/sunflower) on the plasmatic apolipoprotein profile]

FOUNDATIONS: The dietary oil provides a significant portion of the caloric intake in the form of fat, although there is some controversy with respect to the potential positive action of each type of oil. In this study, the effect on the lipo-apoprotein profile of monounsaturated fatty acids (MUFA) provided by olive oil and the polyunsaturated fatty acids (PUFA) provided by girasol oil are compared in a population with high risk of arteriosclerosis, as it is the aged population.

44 aged patients living in the same institution, 21 males and 23 females (age: 79 +/- 6 years), and following two different diets during 3 months, with olive and girasol oils, respectively, participated in the study. Both diets were isocaloric: 2.300 kcal/day, 17% proteins, 33% lipids (30 g/day of oil), and 50% carbohydrates. Plasmatic concentrations of cholesterol (C), triglycerides (TG), c-LDL, c-VLDL, c-HDL2, c-HDL3 and lipoprotein a (Lp[a]), as well as apoproteins A1, B, CII, CIII and E, were assessed. Applied statistics: Student's t test for matched samples.

C and TG plasmatic levels did not changed, whereas levels of c-LDL decreased significantly, as well as levels of polyunsaturated fatty acids (135 +/- 43 and 124 +/- 33 mg/dl., p < 0.009) and levels of apo B (151 +/- 47 and 139 +/- 36 mg/dl., p < 0.009). Levels of c-HDL increased significantly (49 +/- 14 and 52 +/- 16 mg/dl., p < 0.01) as well as levels of apo A1 (190 +/- 32 and 205 +/- 41 mg/dl., p < 0.01). Levels of apo CIII (8.2 +/- 2.8 and 9.9 +/- 3.2 mg/dl., p < 0.008) and apo E (3.2 +/- 1.1 and 3.7 +/- 0.9 mg/dl., p < 0.01) also increased in men. Women did not showed any significant variations in lipoproteins, although apo A1 and apo E increased slightly and apo B decreased, although not significantly, with the polyunsaturated fat. The levels of Lp(a) did not changed.

In the aged population following a standard diet, without overloads, the PUFAs induced positive changes in the lipoapoprotein profile when compared to a previous diet with MUFA. Those changes were more evident in men than in women.