"Whole Protein" Superior to "Isolate."

By Joe Stout B.Sc. M.S. IP

Protein supplements are often offered as whey protein isolates because it has long been thought that isolated whey protein is the best supplement for protein accretion (gain) due to its fast digestion rate. Recently however, there have been various studies that show evidence that casein (milk) protein may have more efficient total body protein accretion capabilities due to its slower digestion rate.

There are two aspects essential to gaining total body protein. One aspect is the concept of protein synthesis. One must enhance protein synthesis in order to build new proteins. The other aspect of protein gain is proteolysis. One must suppress proteolysis which is the destruction of proteins that are already a part of the body. Whey protein does an excellent job of stimulating protein synthesis and casein protein does an excellent job of inhibiting proteolysis. However, whey protein, by itself, does not inhibit proteolysis whereas casein protein does stimulate protein synthesis.

When a person ingests whey protein, the mixture, or bolus, stays soluble in the stomach and is quickly released into the duodenum where it is absorbed into the blood. This is the primary reason that whey protein does such a great job of stimulating protein synthesis because the amino acids are made available very quickly. However, the influx of amino acids is transient because as quickly as they come, the levels drop. The body always naturally desires to stay in an equilibrium or homeostasis so large spikes in any substance be it insulin, carbohydrates, or amino acids should be avoided. However, when casein protein is paired with whey protein, the protein coagulates in the stomach and is slowly released in the duodenum for a slower influx of amino acids into the blood stream. This causes a lower aminoacidemia which means amino acid levels in the blood plasma are not overcompensated by the body. This results in a steady and ultimately superior postprandial (following a meal) amino acid balance.

Testing on various age groups has shown that most people experience the best protein accretion (gain) when both casein protein and whey protein are present in the supplement. As you may know, Caprotein™ is a natural full spectrum protein containing both casein and whey protein. Caprotein™ has been formulated to target several population groups ranging from the elderly to the young and growing. The natural amino acid profile that is present in Caprotein™ provides a high biological value which makes for an excellent choice for those with protein needs. More and more studies are coming to the conclusion that to achieve the best total body protein accretion, a mixture of casein protein and whey protein is desirable. The functional food Caprotein™ provides for this need.