Topical Area: Energy and Macronutrient Metabolism, Obesity
Objectives : Type 2 diabetes mellitus (T2DM) ranks highly on the international health agenda as a global pandemic and as a threat to human health and global economies. Effective preventive strategies are urgently needed. This study was conducted to investigate the effects of cow milk and goat milk on glucose management in high fat-induced obesity (DIO) mice and db/db mice
Methods : In the DIO mouse model, male C57BL/6 mice were randomly assigned into one the following experimental groups and fed the corresponding diet for 16 weeks: negative control (10% caloric fat), high fat control (60% caloric fat), cow milk (high fat with 20% cow milk powder replacing dietary protein), or goat milk (high fat with 20% goat milk powder replacing dietary protein). In the db/db mouse model, female db/db mice were randomly assigned into one of the following experimental groups and consume corresponding AIN-93M based diets: control (AIN-93M diet), cow milk (20% cow milk replacing dietary protein), or goat milk (20% cow milk replacing dietary protein); Conventional C57BL mice were used as the negative control. The glucose tolerance test was conducted at different time points. At the end of the experiments, mice were sacrificed, blood samples were collected for measurement of glucose, insulin, HbA1c and glucagon levels, pancreases were collected for histological and immunohistochemical evaluation, and muscles were collected for RT-PCR analysis.
In the DIO model, both cow milk and goat milk significantly decreased fasting blood glucose (FBG) levels after 14 and 16 weeks of treatment without significant effects on body weight. Goat milk, but not cow milk, significantly reduced serum insulin level. In the db/db model, both cow milk and goat milk significantly decreased FBG and glucose tolerance after 6 weeks of treatment. Goat milk also improved blood levels of insulin, HbA1c and glucagon. Both cow milk and goat milk also improved histopathological damages and markedly up-regulated the expressions of phosphatidylinositol-3-kinase (PI-3K), protein kinase B (Akt), glucose transporters-4 (GLUT4) mRNA involved in the PI-3K/Akt signaling pathway of T2DM.
Conclusions : Our results suggest that dietary intake of cow milk and especially goat milk may significantly improve glucose tolerance, thus may delay the development and progression of type 2 diabetes.
Funding Sources : Feihe Nutrition Laboratory Funds
Harvard Medical School