Efficacy of phytosterols and fish-oil supplemented high-oleic-sunflower oil rich diets in hypercholesterolemic growing rats.

Phytosterols (P) and fish-oil (F) efficacy on high-oleic-sunflower oil (HOSO) diets were assessed in hypercholesterolemic growing rats. Controls (C) received a standard diet for 8 weeks; experimental rats were fed an atherogenic diet (AT) for 3 weeks, thereafter were divided into four groups fed for 5 weeks a monounsaturated fatty acid diet (MUFA) containing either: extra virgin olive oil (OO), HOSO or HOSO supplemented with P or F. The diets did not alter body weight or growth. HOSO-P and HOSO-F rats showed reduced total cholesterol (T-chol), non-high-density lipoprotein-cholesterol (non-HDL-chol) and triglycerides and increased HDL-chol levels, comparably to the OO rats. Total body fat (%) was similar among all rats; but HOSO-F showed the lowest intestinal, epididymal and perirenal fat. However, bone mineral content and density, and bone yield stress and modulus of elasticity were unchanged. Growing hypercholesterolemic rats fed HOSO with P or F improved serum lipids and fat distribution, but did not influence material bone quality.

Aceite de girasol alto oleico: hacia la construcción de una grasa saludable / High oleic sunflower oil supplemented: towards the construction of a healthful fat

Introducción: dado que el aceite de girasol alto oleico (AGAO) es una alternativa viable, ampliamente utilizada, planteamos el agregado de fitoesteroles o aceite de pescado como una nueva estrategia nutricional que logre posicionar al AGAO como una fuente de lípidos saludable. Objetivos: evaluar el efecto del enriquecimiento de AGAO con fitoesteroles (AGAO-F) naturales o suplementación con aceite de pescado (AGAO-n3) sobre el perfil lipídico-lipoproteico, la grasa corporal total y la masa ósea, en un modelo experimental de hipercolesterolemia nutricional (HCN) en crecimiento y analizar el beneficio de dicho enriquecimiento/suplementación en relación al aceite de oliva extra virgen (AO). Materiales y métodos: 48 ratas Wistar macho al destete recibieron por tres semanas (T3) una dieta aterogénica rica en grasa saturada (GS) y col para inducir HCN. A T3 se midió la colesterolemia (col-T) y se dividieron en cuatro grupos. Por cinco semanas (T8), se reemplazó GS por AGAO o AGAO-F o AGAO-n3 o AO. Las dietas se administraron ad libitum y se registró zoometría y consumo (kcal/100g peso corporal/día). A T8 se evaluaron: índice hepatosomático (IH, %), col-T, colnoHDL, col-HDL y TG séricos (mg/dL), % grasa corporal total y distribución, densidad (DMOg/cm2 ) y contenido mineral óseo (CMO,g) de esqueleto total (DPX). Resultados: sin diferencias en peso (g), longitud (cm), consumo e IH. AGAO-F mejoró todos los lípidos séricos. AGAO-n3 mostró menores niveles de col-T, col-noHDL (p=0,000); no de TG. Sin diferencias en grasa corporal y CMO; AGAO-n3: menor porcentaje de grasa intestinal (p=0,003) y DMO (p=0,03). Respecto a AO: AGAO-F y AGAO-n3 mejoraron el perfil-lipídico y AGAO-n3 < grasa intestinal. Conclusiones: en relación a AGAO y AO, AGAO-F y AGAOn3 disminuyeron el riesgo cardiometabólico. En relación a la masa ósea, el agregado de fitoesteroles o aceite de pescado no logró en el tiempo estudiado reducir el riesgo de osteopenia/ osteoporosis impuesto por la HCN.

Introduction: our previous studies demonstrated that the replacement of saturated fat by MUFA rich-diets ameliorated some of the alterations induced by saturated fat. Since high oleic sunflower oil (HOSO) constitutes an important source of MUFA and widely distributed in human nutrition, a supplementation of HOSO may prevent osteopenia and cardiovascular risk improving the biochemical profile. Objectives: the effects of replacing dietary saturated fat, by different ω-9MUFA sources supplemented with natural sterols or fish oil, on serum lipoprotein profile, body fat and distribution, bone mineral content and density in growing hypercholesterolemic rats, were studied. Materials and methods: forty eight Wistar rats (aged=21days) were fed "ad libitum" with an atherogenic diet, rich in saturated fat and cholesterol for 3 weeks, to induce hypercholesterolemia. Then, rats were randomly assigned to one of 4 groups, according to the source of oil replacing saturated fat: extra virgin olive oil (OO); HOSO, HOSO plus phytosterols (HOSO-P) or HOSO plus fish-oil (HOSO-F) for 5 weeks. After 3 weeks, zoometrics and diet consumption were recorded; hepatic index (HI), serum lipids, body fat content and distribution, bone mass content (BMC) and density (BMD), were assessed. Results: groups showed no significant differences in zoometrics, diet consumption and HI (p>0,05). HOSO-P rats showed a reduction in T-Chol and nonHDL-Chol and the lowest TG levels; HOSO-F showed lower T-chol and non HDL-chol levels (p=0,000), but not TG. Total body fat and BMC were not different among groups. HOSO-F rats showed the lowest intestinal fat content (p=0,003) and BMD (p=0,03). When compared to OO, HOSO-P and HOSO-F improved serum lipids and additionally, HOSO-F showed a reduction in intestinal fat. Conclusions: The replacement of saturated fat rich-diet by HOSO supplemented with phytosterols or fish oil induces bene- ficial effects on serum lipids and cardiovascular disease. However, they could not prevent the detrimental effects on bone.

Monounsaturated fatty acids-rich diets in hypercholesterolemic-growing rats.

The effects of replacing dietary saturated fat by different monounsaturated fatty acid (ω-9MUFA) sources on serum lipids, body fat and bone in growing hypercholesterolemic rats were studied. Rats received one of the six different diets: AIN-93G (control, C); extra virgin olive oil (OO) + C; high-oleic sunflower oil (HOSO) + C or atherogenic diet (AT) for 8 weeks; the remaining two groups received AT for 3 weeks and then, the saturated fat was replaced by an oil mixture of soybean oil added with OO or HOSO for 5 weeks. Rats consuming MUFA-rich diets showed the highest body fat, hepatic index and epididymal, intestinal and perirenal fat, and triglycerides. T-chol and non-HDL-chol were increased in HOSO rats but decreased in OO rats. Bone mineral content and density were higher in both OO and HOSO groups than in AT rats. This study casts caution to the generalization of the benefits of MUFA for the treatment of hypercholesterolemia.