Effects of milk proteins supplementation on muscle protein synthesis

Purpose The purpose of the study was to evaluate the acute effect of milk proteins supplementation, compared to another nitrogen compound on muscle protein synthesis. Design/methodology/approach The search was conducted on MEDLINE® (via PUBMED®), Cochrane and Embase databases, using the terms “whey proteins,” “caseins,” “milk proteins,” “protein biosynthesis,” “human” and its related entry terms. The selected outcome was fractional synthetic rate (FSR) before (0) and 3 h after consumption of milk proteins, compared to supplementation with other protein sources or isolated amino acids. Findings The results were expressed as mean difference (MD) of absolute values between treatments with confidence interval (CI) of 95 per cent. Of the 1,913 identified studies, 4 were included, with a total of 74 participants. Milk proteins generated a greater FSR (MD 0.03 per cent/h, CI 95 per cent 0.02-0.04; p < 0.00001), compared to control group. Acute consumption of milk proteins promotes higher increase in FSR than other protein sources or isolated amino acids. Originality/value This paper is a systematic review of the effects of milk proteins supplementation, which is considered an important subject because of its large consumption among athletes and physical exercise practitioners.