Abdominal adiposity, insulin and bone quality in young male rats fed a high-fat diet containing soybean or canola oil

Abstract

OBJECTIVES:A low ratio of omega-6/omega-3 polyunsaturated fatty acids is associated with healthy bone properties. However, fatty diets can induce obesity. Our objective was to evaluate intra-abdominal adiposity, insulin, and bone growth in rats fed a high-fat diet containing low ratios of omega-6/omega-3 provided in canola oil.METHODS:After weaning, rats were grouped and fed either a control diet (7S), a high-fat diet containing soybean oil (19S) or a high-fat diet of canola oil (19C) until they were 60 days old. Differences were considered to be significant if p<0.05.RESULTS:After 60 days, the 19S and 19C groups showed more energy intake, body density growth and intra-abdominal fat mass. However, the 19S group had a higher area (200%) and a lower number (44%) of adipocytes, while the 7S and 19C groups did not differ. The serum concentrations of glucose and insulin and the insulin resistance index were significantly increased in the 19C group (15%, 56%, and 78%, respectively) compared to the 7S group. Bone measurements of the 19S and 19C groups showed a higher femur mass (25%) and a higher lumbar vertebrae mass (11%) and length (5%). Computed tomography analysis revealed more radiodensity in the proximal femoral epiphysis and lumbar vertebrae of 19C group compared to the 7S and 19S groups.CONCLUSIONS:Our results suggest that the amount and source of fat used in the diet after weaning increase body growth and fat depots and affect insulin resistance and, consequently, bone health.

Buriti oil (Mauritia flexuosa L.) negatively impacts somatic growth and reflex maturation and increases retinol deposition in young rats

“…Lower n6/n3 ratio induced reduction on body bone area and body bone mineral content (BMC), which is reflected in the lower spine area and spine BMC (Costa et al, (2012). However, the study by Costa et al (2011) showed an increase of 5% in the length of puppies who consumed high fat diet added with 19% of canola or soybean oil (fat diet) compared with the control group (7% of soybean oil). These findings showed that both the quantity and quality of dietary lipids interfer in puppies' length.…”

Body adiposity and bone parameters of male rats from mothers fed diet containing flaxseed flour during lactation

“…4 The effects of fat tissue on bone health are far from clear: investigators have suggested that fat mass may or may not be associated with bone mass, directly via mechanical loading and indirectly via hormonal production by adipocytes. 5,6 Clinical and experimental studies have reported on the importance of α-linolenic acid (ALA, 18:3n-3)-rich diets for adiposity accumulation prevention and promotion of bone formation. Conversely, linoleic acid (LA, 18:2n-6) contributes to bone reabsorption and adipocyte hypertrophy.…”

High-fat Diets Containing Soybean or Canola Oil Affect Differently Pancreas Function of Young Male Rats

“…Furthermore, the chronic intake of high-fat diet (HF) per se can be one independent factor to insulin resistance [ 3 ] . In previous studies, we observed higher glycemia and insulinemia in rats fed with HF diet containing 19 % canola oil [ 4 ] . However, the mechanisms of this alteration in glucose homeostasis remain not well explained.…”

“…Retroperitoneal and epididymal fat depots were dissected and the mass was expressed as total (g) and fractional (g/100 g) (adjusted to total body mass). Based on serum analyses of glucose and insulin [ 4 ] , the homeostasis model assessment-insulin resistance (HOMA-IR) and HOMA of pancreatic β-cell function (HOMA-β) indexes were calculated, according to the following equations: The homeostasis model assessment of insulin resistance (HOMA-IR): [insulin (μIU/ml) × serum glucose (mmol/l)]/22.5; HOMA-β: [insulin (μIU/ml) × 20]/serum glucose (mmol/l)-3.5. HOMA-IR is more related to insulin resistance, while HOMA-β is related to insulin secretion [ 7 ] .…”