Amino Acids & Protein Powders
Amino acids are the building blocks of protein, and proteins are the building blocks of life. The human body is constantly assembling, breaking down and using proteins on a daily basis. In fact, 10 to 25% of caloric energy should come from high-quality, complete proteins. However, the role of amino acids is not only limited to the synthesis of proteins. They also function as intermediates in metabolism. There are twenty “standard” amino acids used by cells in protein biosynthesis. Of the 20+ amino acids, 9 are “essential” and are required in the diet since the body cannot produce them. “Nonessential” amino acids, on the other hand, are produced in the body from other amino acids when given an adequate supply of nitrogen, carbon, hydrogen and oxygen. Yet, even some of these nonessential amino acids are necessary at certain life stages or during certain situations, which is why some are considered “conditionally essential.” (see Table 1)
Table 1: AMINO ACIDS A TO Z
|Essential Amino Acids||Conditionally Essential Amino Acids||Nonessential Amino Acids|
|Isoleucine||Cysteine or N-acetyl-cysteine (NAC)||Asparagine (Aspartic Acid)|
|Leucine||Glutamine (Glutamic Acid)||Ornithine|
In general, although both animal and plant foods contain protein, the quality of the protein is what differs. High-quality (complete) protein provides an ample amount of all nine essential amino acids. Animal foods, such as meats, poultry, eggs and milk, are considered high-quality (complete) protein sources versus vegetables, which contain no or low levels of some of the essential amino acids with the exception of soybeans. Egg white albumin is the main protein found in egg white, making up 60-65% of the total protein. Whey is one of the principal proteins that is found in milk and is the protein of choice because of its superior biological value (BV) of 159, as well as being a rich, natural source of branched chain amino acids (BCAAs) and immunoglobulins (see Table 2).