Effects of supplementation with milk protein on glycemic parameters: a GRADE-assessed systematic review and dose–response meta-analysis

Abstract

Abstract Background It is suggested that supplementation with milk protein (MP) has the potential to ameliorate the glycemic profile; however, the exact impact and certainty of the findings have yet to be evaluated. This systematic review and dose–response meta-analysis of randomized controlled trials (RCTs) assessed the impact of MP supplementation on the glycemic parameters in adults. Methods A systematic search was carried out among online databases to determine eligible RCTs published up to November 2022. A random-effects model was performed for the meta-analysis. Results A total of 36 RCTs with 1851 participants were included in the pooled analysis. It was displayed that supplementation with MP effectively reduced levels of fasting blood glucose (FBG) (weighted mean difference (WMD): -1.83 mg/dL, 95% CI: -3.28, -0.38; P = 0.013), fasting insulin (WMD: -1.06 uU/mL, 95% CI: -1.76, -0.36; P = 0.003), and homeostasis model assessment of insulin resistance (HOMA-IR) (WMD: -0.27, 95% CI: -0.40, -0.14; P 8 weeks) with high or moderate doses (≥ 60 or 30–60 g/d) of MP or whey protein (WP). Serum FBG levels were considerably reduced upon short-term administration of a low daily dose of WP (< 30 g). Furthermore, the levels of serum fasting insulin were remarkably decreased during long-term supplementation with high or moderate daily doses of WP. Conclusion The findings of this study suggest that supplementation with MP may improve glycemic control in adults by reducing the values of fasting insulin, FBG, and HOMA-IR. Additional trials with longer durations are required to confirm these findings.

Keywords

• Glycemic indices
• High blood glucose (HBG)
• Hyperglycemia
• Milk protein
• Whey protein
• Casein protein