Our Body Depends On 20 Amino Acids

Some We Can Generate Ourselves But All 20 Amino Acids Are Necessary For Health

Amino acids are the building blocks of protein. There are 20 amino acids necessary to build the various proteins used in the growth, repair, and maintenance of body tissues. Eleven of these amino acids can be made by the body itself, while the other nine (called essential amino acids) must come from the diet. The classification of an amino acid as essential or nonessential does not reflect its importance, because all 20 amino acids are necessary for health. Instead, this classification system simply reflects whether or not the body is capable of manufacturing a particular amino acid.

Of the 20 amino acids, the essential ones are isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. Another amino acid, histidine, is considered semi-essential because the body does not always require dietary sources of it. The nonessential amino acids are arginine, alanine, asparagine, aspartic acid, cysteine, glutamine, glutamic acid, glycine, proline, serine, and tyrosine. Other amino acids, such as carnitine, are used by the body in ways other than protein-building and are often used therapeutically.

While the 20 amino acids are required for proper health, foods of animal origin, such as meat and poultry, fish, eggs, and dairy products, are the richest dietary sources of the essential amino acids. Plant sources of protein are often deficient in one or more essential amino acids. It was previously believed that, in order for vegetarians to obtain adequate amounts of protein, all of the essential amino acids had to be “balanced” at each meal. For example, a grain and a bean had to be consumed at the same meal. However, it is not necessary to consume all of the amino acids at the same meal.