Impacto da dieta hiperlipídica contendo óleo de canola ou de soja no desenvolvimento da adiposidade abdominal e estrutura óssea

Abstract

The lower ratio of omega-6 to omega-3 polyunsaturated fatty acids is associated with healthy bone properties. However, fat diets can induce obesity. Adipocytes and osteoblasts derive from a common progenitor, and canola oil intake may have an adipogenic and osteogenic effect. Our objective was to evaluate the intra-abdominal adiposity, insulin and bone growth in rats fed diet containing lower ratio of omega-6 to omega-3, provided in canola oil. After weaning, rats were divided into groups fed with normocaloric diet: control (S) and experimental (C), containing 7ml/100g soybean or canola oil, respectively and groups fed with fat diet: control (7S) or fat diets containing 19ml/100g soybean oil (19S) or canola oil (19C), until they 60 days old. Differences were considered significant with P<0,05. In normocaloric diet model, C group showed a significant reduction in: Intra-abdominal fat mass; Area of adipocyte; Cholesterol; Insulin; Total body and spine bone mineral content and bone area; Femur mass; Width of the diaphysis; Femur and lumbar vertebrae bone mineral density and radiodensity of femoral head. To high-fat diet model, 19S and 19C groups showed higher energy intake, body density growth, intra-abdominal fat mass and higher femur mass and, lumbar vertebrae mass and length. 19S showed higher area and lower number of retroperitoneal adipocytes. Glucose and insulin were significantly increased in 19C compared to 7S group. Computed tomography of femur revealed higher radiodensity in proximal femoral epiphysis and lumbar vertebrae of 19C. We suggest that the amount and the source of fat used in the diet, after weaning, induce not only the body and fat depots growth, besides affecting the insulin resistance and the bone health