Supplementation of cow milk naturally enriched in polyunsaturated fatty acids and polyphenols to growing rats

Abstract

This study investigated whether intake of cow milk, naturally enriched with polyunsaturated fatty acids (PUFA, omega-3) and polyphenols (from propolis extract and vitamin E), from manipulation of cow’s diet, would result in positive metabolic effects in rats from weaning until adulthood. Male Wistar rats were fed a standard chow diet or a hypercaloric diet (metabolically disturbed rats, obese) which was supplemented with either whole common milk, milk enriched with PUFA (PUFA-M) or milk enriched with PUFA and polyphenols (PUFA/P-M), at 5mL/kg body weight,having water as control. Whole milk supplementation increased initial weight gain and reduced gain in the adulthood of rats. Intake of common milk reduced cholesterol levels in non-obese rats and reduced insulin resistance in obese rats. PUFA-milk showed a decreasing effect on plasma triacylglycerol and VLDL concentrations, increasing plasma HDL concentration and reducing adipocyte size of non-obese rats, but no effect was observed in obese rats. PUFA/P-milk in obese rats resulted in greater deposition of muscle mass and mesenteric fat, with a tendency to lower LDL levels, and resulted a visceral fat accumulation in non-obese rats. Thus, whole common milk and PUFA-rich milk have shown to be beneficial in a normal metabolic condition, whereas common milk and milk enriched with PUFA and polyphenols improve metabolic effects of obesity.

Functionality of cow milk naturally enriched with polyunsaturated fatty acids and polyphenols in diets for diabetic rats

“…Other similar studies in the diabetic animal model were not found in the literature [ 18 ]. Thus, we could verify that supplementing the diets of dairy cows with PUFA-rich oil and polyphenols transfers part of these compounds into milk.…”

“… 1 Milk composition reported by Santos et al [ 18 ]. Data are mean ± standard deviation from a single sample for each treatment.…”

“…Determination of milk chemical composition, fatty acid composition, and antioxidant composition was described by Santos et al [ 18 ]. Determination of blood concentrations of glucose, fructosamine, total cholesterol, HDL cholesterol, triacylglycerol, aspartate aminotransferase, and alanine aminotransferase were determined using colorimetric methods (Gold Analisa ® , Belo Horizonte, MG, Brazil) and measured on a spectrophotometer (Bioplus2000 ® , São Paulo, SP, Brazil).…”

“…Differentiated diets for dairy cows with polyunsaturated fat (n3) and polyphenols can naturally enrich milk with PUFA and polyphenols [ 17 ]. In a recent study, the administration of this enriched milk as a supplement to obese rats has resulted in increased muscle mass and reduced LDL values [ 18 ].…”

“…In this experiment, diabetic rats received supplementation with milk naturally enriched with PUFA and polyphenols, obtained by manipulation of dairy cow diet [ 17 , 18 ] to test the hypothesis that enriched cow milk could be a functional food, and facilitate the prevention and treatment of diabetes. Thus, the objective of this study was to determine the effects of such supplementation on feed intake, growth, blood parameters, glucose tolerance and body composition.…”