Soy and Casein Maintain Muscle Mass

Soy and casein are equally effective for muscle protein synthesis, according to a study published in Clinical Nutrition. Although differences between the proteins were observed regarding uptake of amino acids in the leg, both protein sources were found to be effective in maintaining muscle mass. Previous studies have suggested that casein is more effective at raising body protein levels than the equivalent level of soy protein.

For the study, 22 healthy 22-year-olds were randomly assigned to consume casein or soy meals. At the end of the study, researchers found no significant difference in acute muscle protein metabolism. 

However, in addition to differences between the proteins for the uptake of amino acids in the leg, the researchers noted differences in changes in levels of glutamate, glutamine, serine, histidine, isoleucine and branched chain amino acids.

Commenting on the study results, Johann Tergesen, president and COO of Burcon NutraScience Corporation, said: Soy is a widely accepted, economical source of high quality plant protein, with both a balanced nutritional profile and recognized health benefits. Plant proteins offer a more environmentally friendly alternative to animal derived proteins."