Objective: To investigate the effects of whey protein on insulin resistance in model rats.
Methods: Insulin resistance model rats were established by feeding high-fat diet in Wistar rats. Model rats were then randomly divided into 4 groups of 10 animals each and fed on 0% whey protein (WP), 5% WP and 15% WP. After 8 weeks, fasting blood glucose (FBG), fasting plasma insulin (FINS) were determined. Oral glucose tolerance test (OGTT) was performed and glucose area under the curve (AUC) was calculated. Also, plasma total anti-oxidation capacity (T-AOC), superoxide dismutase (SOD), reduced glutathione hormone (GSH) and malondialdehyde (MDA) were determined.
Results: Whey protein intake did not affected FBG and glucose AUC. FINS and homeostatic model assessment-insulin resistance (HOMA-IR) were significantly lower in 15% WP group than in 0% WP group. For antioxidant index,plasma level of T-AOC, SOD and GSH were significantly higher in 15% WP group than in 0% WP group (T-AOC : P < 0.01; SOD, GSH : P < 0.05); however, MDA was significantly lower in 15% WP group than in 0% WP group (P < 0.05).
Conclusion: Whey protein improves insulin resistance. This effect is related to the increase of antioxidant capacity in insulin resistance model rats.