RESUMEN
PURPOSE: There is an increased interest in the benefits of conjugated α-linolenic acid (CLNA) on obesity-related complications such as insulin resistance and diabetes. The aim of the study was to investigate whether a 1% dietary supplementation of mono-CLNA isomers (c9-t11-c15-18:3 + c9-t13-c15-18:3) improved glucose and lipid metabolism in neonatal pigs. METHODS: Since mono-CLNA isomers combine one conjugated two-double-bond system with an n-3 polyunsaturated fatty acid (PUFA) structure, the experimental protocol was designed to isolate the dietary structural characteristics of the molecules by comparing a CLNA diet with three other dietary fats: (1) conjugated linoleic acid (c9-t11-18:2 + t10-c12-18:2; CLA), (2) non-conjugated n-3 PUFA, and (3) n-6 PUFA. Thirty-two piglets weaned at 3 weeks of age were distributed among the four dietary groups. Diets were isoenergetic and food intake was controlled by a gastric tube. After 2 weeks of supplementation, gastro-enteral (OGTT) and parenteral (IVGTT) glucose tolerance tests were conducted. RESULTS: Dietary supplementation with mono-CLNA did not modify body weight/fat or blood lipid profiles (p > 0.82 and p > 0.57, respectively) compared with other dietary groups. Plasma glucose, insulin, and C-peptide responses to OGTT and IVGTT in the CLNA group were not different from the three other dietary groups (p > 0.18 and p > 0.15, respectively). Compared to the non-conjugated n-3 PUFA diet, CLNA-fed animals had decreased liver composition in three n-3 fatty acids (18:3n-3; 20:3n-3; 22:5n-3; p < 0.001). CONCLUSIONS: These results suggest that providing 1% mono-CLNA is not effective in improving insulin sensitivity in neonatal pigs.
Asunto(s)
Suplementos Dietéticos , Modelos Animales de Enfermedad , Intolerancia a la Glucosa/prevención & control , Resistencia a la Insulina , Metabolismo de los Lípidos , Hígado/metabolismo , Ácido alfa-Linolénico/uso terapéutico , Animales , Canadá , Cruzamientos Genéticos , Suplementos Dietéticos/análisis , Emulsiones , Ácidos Grasos Insaturados/análisis , Ácidos Grasos Insaturados/química , Ácidos Grasos Insaturados/metabolismo , Ácidos Grasos Insaturados/uso terapéutico , Femenino , Intolerancia a la Glucosa/sangre , Intolerancia a la Glucosa/metabolismo , Intolerancia a la Glucosa/patología , Hígado/patología , Masculino , Orquiectomía/veterinaria , Distribución Aleatoria , Estereoisomerismo , Sus scrofa , Destete , Aumento de Peso , Ácido alfa-Linolénico/análisis , Ácido alfa-Linolénico/química , Ácido alfa-Linolénico/metabolismoRESUMEN
The aim of the present study was to perform a short-term safety evaluation of dietary mono-conjugated α-linolenic acid isomers (CLNA; c9-t11-c15-18:3+c9-t13-c15-18:3) using a neonatal pig model. CLNA diet was compared with three other dietary fats: (1) conjugated linoleic acid (CLA; c9-t11-18:2+t10-c12-18:2), (2) non-conjugated n-3 PUFA and (3) n-6 PUFA. Thirty-two piglets weaned at 3 weeks of age were distributed into four dietary groups. Diets were isoenergetic and food intake was controlled by a gastric tube. Mono-CLNA diet did not significantly change body or organ weight, carcass composition and most biochemical parameters including; glucose, cholesterol, triglycerides, creatinine, blood urea nitrogen, hepatic enzymes and electrolytes levels in blood (P⩾0.09). Conversely, the n-3 PUFA composition of the brain, liver and heart decreased by 6-21% in the CLNA-fed group compared to animals fed nonconjugated n-3 PUFA (P<0.01). Responses to dietary treatments were tissue-specific, with the liver and the brain being the most deprived in n-3 PUFA. Our results support that short-term intake of mono-CLNA is safe in neonatal pigs but n-3 PUFA reduction in tissues deserves to be further investigated before using long-term nutritional supplementation in pigs and other animal models and before moving to clinical trials.