Protein researchers have known for years that only the essential amino acids (the ones our body cannot make) are needed to boost protein synthesis. This is one reason why whey protein is so effective because it has a high ratio of essential amino acids compared to other protein sources.
Prominent protein researchers decided to do a clever experiment. They compared three trials. One provided 15g of intact whey protein (regular whey protein powder). The other 2 trials provided either the individual essential amino acids (7g) or the individual non-essential amino acids (8g) found in whey. Protein balance was measured for 3.5 hours after ingestion.
They predicted that providing just the free-form essential amino acids typically found in whey would result in the same increase in protein synthesis as the whey protein powder. Yet, here’s what they found: The non-essential amino acid trial resulted in essentially no change in protein balance, whereas the essential amino acid trial resulted in a small increase. After the whey protein powder ingestion, protein balance was markedly increased.
The findings were somewhat surprising because it indicates that the essential amino acid content of whey is not solely responsible for the anabolic effects. The results have implications for formulation of protein supplements and suggest that intact whey protein powder has some benefits beyond what can be achieved by only providing its essential amino acids.
Katsanos CS, Chinkes DL, Paddon-Jones D, Zhang XJ, Aarsland A, Wolfe RR. Whey protein ingestion in elderly persons results in greater muscle protein accrual than ingestion of its constituent essential amino acid content. Nutr Res. 2008 Oct;28(10):651-8.