A study published in The Journal of Nutrition found that a soy and dairy protein blend promoted muscle protein synthesis after exercise (J. Nutr. March 1, 2013 jn.112.168021). In this double-blind, randomized clinical trial, researchers at the University of Texas compared a soy/dairy protein blend (using SUPRO from DuPont Nutrition & Health) with whey protein, measuring fractional synthetic rate and branch-chain amino acid (BCAA) concentrations.
Muscle biopsies from 19 participants were collected at rest and at two intervals post-exercise and protein ingestion. The whey protein group showed an earlier peak in blood BCAA levels, while the blend group maintained elevated BCAA levels longer into recovery. Additionally, the protein blend resulted in a prolonged elevation of fractional synthetic rate compared to whey. “Sources of high-quality protein contain all essential amino acids and offer unique advantages for muscle growth,” stated Blake Rasmussen, Ph.D., interim chair of DuPont’s nutrition and metabolism department and principal investigator. This study is the first to examine combining soy with dairy proteins (whey and casein) for lean body mass gain. Research on soy protein benefits is expanding; an October PLOS One study indicated soy protein reduces body and liver fat. For more on protein applications in natural products, visit INSIDER’s Protein Topic Feed.
