Dietas con diferentes fuentes y concentraciones lipídicas: modificaciones sobre el perfil de ácidos grasos en suero y cerebro. Modelo experimental / Diets with different sources and lipidic concentrations: alterations on the profile of serum fatty acids and brain. Experimental model

Un adecuado perfil de ácidos grasos en la dieta es importante para el crecimiento y desarrollo del sistema nervioso durante las distintas etapas de la vida. El sistema nervioso central está constituido predominantemente por lípidos, gran parte de ellos está formado por ácidos grasos esenciales que no pueden ser sintetizados por el organismo y deben ser aportados por la dieta. Los ácidos grasos omega 3 y omega 6 resultan determinantes en el desarrollo cerebral. El objetivo fue analizar el efecto de dietas con diferentes fuentes lipídicas, con contenido recomendado y alto de lípidos, administradas durante 10 días a ratas en período de crecimiento activo. Se evaluaron los niveles séricos de triglicéridos, colesterol total y el perfil de ácidos grasos en suero y cerebro. Se realizaron experiencias utilizando dietas conteniendo F%15 ó 42 (F%=kcal lipídicas/100 kcal totales). Las fuentes lipídicas utilizadas fueron las siguientes: manteca (Dieta M), aceite de oliva (Dieta O), aceite de girasol alto oleico (Dieta AO), aceite de girasol (Dieta G). La dieta control en todas las experiencias fue normocalórica (F%=15, aceite de soja). Los resultados demostraron que sólo el grupo M que recibió una dieta con un F%=42 presentó aumento del colesterol total y triglicéridos. En suero los grupos M, O y AO mostraron aumento de ácido oleico y disminución de ácidos linolénico y linoleico. El grupo G sólo presentó disminución de ácido linolénico. El perfil de ácidos grasos en cerebro en todas las experiencias no mostró cambios. La modificación en el perfil de ácidos grasos en suero de los grupos M, O y AO estuvo relacionada con la fuente de lípidos utilizada para su elaboración y no con el F% de la dietas. Por otra parte, los cambios que presentaron los ácidos grasos en suero no se observaron en cerebro. Estos resultados sugerirían que el organismo trata de suplir las necesidades de ácidos grasos del cerebro a expensas de su modificación en suero.

Diet lipid profile is important for the growth and development of the nervous system during the different stages of life. The central nervous system consists predominantly of lipids, many of themare composed of fatty acids, which cannot be synthesized by the body and must be supplied by diet. The ω3 and ω6 fatty acids are determinants in the development of the brain. The objective of this sutudy is to analyze the effect of different sources of dietary lipids with normal and high concentration, on serum levels of triglycerides, total cholesterol and fatty acids profile in serum and brain of growing rats. Experimental diets contained F% 15 and 42 (F%=kcal of lipids/ total kcal), provided by butter (M), olive oil (O), sunflower oil high oleic acid (AO) and sunflower oil (G). Control diet (C) was normocaloric, with 15%kcal of lipids provided by soy oil. Only the M group that received a diet with F%=42 increase total cholesterol and triglycerides. M, O and AO groups in serum, show increase of oleic acid and decrease of linolenic and linoleic acids. G group has only decrease linolenic acid. Brain fatty acids profile in all the experiences shows no changes. The administration of these diets provoked changes in serum fatty acid profile in response to the differences sources of dietary lipids used and not with the F% of the diets. On the other hand, changes in serum fatty acids profile, were not observed in brain. These results suggest that the body tries to compensate the fatty acids needs of the brain at the expense of its modification in serum

Effects of high-fat diets from different sources on serum and thymus lipid profile: study in an experimental model.

BACKGROUND: A balanced diet is important to maintain an optimal health status and to prevent noncommunicable chronic diseases. The principal objective of this study was to analyze the effect of diets containing high fat levels from different sources, on serum and thymus lipid profile, in adult rats. METHODS: Experimental diets contained 50% kcal of fat, provided by butter (B) or sunflower oil (S); control diet (C) was isocaloric, with 15 kcal of fat per 100 total kcal, provided by soy oil. Diets were otherwise complete in all nutrients and were administered for 40 days. RESULTS: Group B had higher levels of total cholesterol and triglycerides than C; S serum lipid profile did not differ from C, despite the higher fat content. Regarding serum and thymus FA profile, B showed an increase of saturated fatty acids and lower levels of ω6 and ω3 FA, and S had lower levels of ω3 fatty acids. CONCLUSIONS: The administration of high-fat diets, during 40 days to adult rats, provoked specific variations on serum and thymus fatty acids, as a consequence of differences in FA profile of their lipid sources. These results reflect the impact that eating habits have on health status. It is important to put emphasis not only on the reduction of total fat intake, but also on choosing healthy sources of fat, replacing saturated fatty acids by polyunsaturated and including oils with higher content of ω3 to keep a balanced ω6/ω3 ratio.