Efecto sinérgico antioxidante de las vitaminas E y C sobre la lipoproteína de baja densidad en fumadores y no fumadores / Synergistic antioxidative effect of vitamins E and C on low density lipoproteins from smokers and non-smorkers subjects

La peroxidación de los lípidos de la LDL es un paso importante en la aterogenicidad de esta partícula lipídica, por otra parte el humo del tabaco promueve el stress oxidativo, reduce la concentración endógena de alfa-tocoferol (vitamina E) contenida en la LDL y la concentración de vitamina C del plasma. El objetivo del presente estudio a doble ciego, randomizado fue examinar el efecto de la administración simultánea de las vitaminas E y C sobre la suceptibilidad a la oxidación de la LDL aislada de 20 sujetos fumadores y 10 no fumadores voluntarios, sanos a quienes se administró placebo por 15 días y luego durante 30 días la combinación de vitamina E (400 mg/d) y vitamina C (1000 mg/d). Al final de la administración del placebo y las vitaminas, el colesterol total, LDL-colesterol y HDL-colesterol del plasma no cambiaron significativamente (p>0,05) y los triglicéridos aumentaron significativamente (p<0,05) pero sin sobrepasar el rango normal. La suceptibilidad a la oxidación de la LDL disminuyó 41,3 por ciento en los fumadores y 54,4 por ciento en los no fumadores (p<0,05 vs período pacebo). En conclusión, las vitaminas E y C administradas simultáneamente ejercen un potente efecto antioxidante en la peroxidación de los lípidos de la LDL. Este efecto puede representar un mecanismo atenuador de la aterogénesis incrementada en los sujetos fumadores de cigarrillos

Modificaciones de las lipoproteínas del plasma después del uso dietético de la oleína de palma en adultos sanos / Changes in of plasma lipoproteins after the use of palm oil in the diet of a group healthy adults

Although saturated fat acids have long known to have harmful effects on cholesterol and triacylglycerides levels in blood, new concepts have emerged form recent research on this matter. The purpose of this study was to know the effect of the consumption of palm olein on triacylglycerides and cholesterol levels as well as lipoprotein fractions in the blood plasma of healthy individuals from both sexes. MATERIALS AND METHODS: Different types of fats were administered for 12 weeks to 60 subjects, 45 male, 15 female, between 19 and 45 years of age, who were divided into three groups: the mix group (MG) was administered oil, margarine, and mayonnaise prepared with 50 olein; the olein group (OG) consumed fats prepared with 100 olein; and the control group (CG) consumed regular fats of customary use by the population. The diets provided 25 to 30 of calories. Blood samples were obtained for lipid analysis at the beginning and the end of the study. Plasma triacylglycerides and cholesterol concentrations were determined by means of enzyme and lipoprotein methods (VLDL, LDL; and HDL) by ultracentrifugation. RESULTS AND DISCUSSION: By comparing the groups' means no significant differences were found (p > 0.05) in blood lipids. Individual differences show a slight increase in VLDL-C in OG compared to MG and CG. No differences were found in LDL concentration. CONCLUSIONS: These results contribute evidence to differentiate between the effects of saturated vegetables oils, such as coconut oil, and of palm olein. The authors recommend not extrapolate the effects of type of oil to another in connection with TC increase in blood.