How many essential amino acids are there for human health?

There are nine essential amino acids that are crucial for human health. These amino acids cannot be synthesized by the body and must be obtained through dietary sources. The essential amino acids are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.

Essential amino acids play vital roles in various bodily functions, including protein synthesis, hormone production, and neurotransmitter regulation. Regular intake of these amino acids is important to maintain metabolic processes and overall health.

Other numbers mentioned, like five, eleven, and twenty, do not accurately reflect the count of essential amino acids. While the body needs a total of twenty amino acids to function—eleven of which are non-essential and can be produced by the body—the focus here is specifically on those nine that must be acquired from food sources.