Amino acids play many different roles in promoting overall health.  Amino acids function in building cells and repairing tissue, they help fight bacteria and viruses, are part of the enzyme and hormonal system, contribute to building nucleoproteins and play an important role in respiration and muscle activity.  When proteins are digested, they break down into 22 known amino acids.

• Essential
• Conditionally essential
• Nonessential

Essential amino acids: The amino acids that adults cannot synthesize and must be provided by diet: methionine, valine, phenylalanine, isoleucine, threonine, tryptophan, histidine, leucine, and lysine. Cysteine and tyrosine are considered essential amino acids for the preterm and young term infant because of the immaturity of the enzyme activities involved in their synthesis.  Valine, isoleucine, and leucine are collectively referred to as branched-chain amino acids (BCAA) and are reported to support energy and muscle building. BCAA directly supply energy to the skeletal muscles during intense exercise, instead of first being metabolized through the liver like the other amino acids.

Whey proteins contain almost 26% of the BACC, leucine, isoleucine, and valine. Whey proteins are also a good source of the sulfur-containing amino acids, cysteine and methionine.  These amino acids maintain antioxidant levels in the body and are thought to stabilize DNA during cell division.

While animal foods are the best source of complete protein with all the essential amino acids, some plant sources, such as soy, also contain the full spectrum of critical amino acids.

Conditionally essential amino acids: Taurine, carnitine, and glycine are in this category.  Ordinarily, they can be synthesized, but an exogenous source is required under certain circumstances.  L-Carnitine is a naturally occurring amino acid essential for metabolic coversion of fat to energy; it transports long-chain fatty acids the membrane into the mitochondria so that it can be metabolized.