Amino acids, often referred to as the building blocks of proteins, are compounds that play many critical roles in your body. They’re categorized as essential, conditionally essential, or nonessential depending on several factors.
You need them for vital processes such as building proteins, hormones, and neurotransmitters.
Amino acids are concentrated in protein-rich foods such as meat, fish, and soybeans.
Some people also take certain amino acids in supplement form as a natural way to boost athletic performance or improve mood.
In this article you’ll find all the basics about essential amino acids, including how they function, food sources rich in essential amino acids, and the potential benefits of taking a supplement.
What are essential amino acids?
Your body needs 20 different amino acids to grow and function properly. While all 20 of these are important for your health, only 9 are classified as essential.
These are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.
Essential amino acids can’t be made by the body, so you have to get them from your diet.
The best sources of essential amino acids are animal proteins such as meat, eggs, and poultry. However, some plant foods, such as the soy products edamame and tofu, contain all nine essential amino acids
After you eat protein, your body breaks it down into amino acids and then uses them for various processes, such as building muscle and regulating immune function
Conditionally essential amino acids
Several nonessential amino acids are classified as conditionally essential.
These are essential only under specific circumstances, such as during illness, pregnancy, infancy, or trauma.
For example, arginine is considered nonessential, but your body can’t make as much as you need when you’re healing from a serious injury or fighting certain diseases, such as cancer
That’s why, in certain situations, people may take arginine supplements to meet their bodies’ needs.
Additionally, certain amino acids, including glycine and arginine, are considered conditionally essential during pregnancy because a pregnant person needs more of these amino acids to support their own health and the health of the fetus
The functions of essential amino acids
There are nine essential amino acids, each of which performs a number of important jobs in your body:
Phenylalanine.
Your body turns this amino acid into the neurotransmitters tyrosine, dopamine, epinephrine, and norepinephrine. It plays an integral role in the structure and function of proteins and enzymes and the production of other amino acids .
Valine.
This is one of three branched-chain amino acids (BCAAs) on this list. That means it has a chain branching off from one side of its molecular structure. Valine helps stimulate muscle growth and regeneration and is involved in energy production .
Threonine.
This is a principal part of structural proteins, such as collagen and elastin, which are important components of your skin and connective tissue. It also plays a role in fat metabolism and immune function
Tryptophan.
Often associated with drowsiness, tryptophan is a precursor to serotonin, a neurotransmitter that regulates your appetite, sleep, and mood .
Methionine.
This amino acid plays an important role in metabolism and detoxification. It’s also necessary for tissue growth and the absorption of zinc and selenium, minerals that are vital to your health .
Leucine. Like valine, leucine is a BCAA that is critical for protein synthesis and muscle repair. It also helps regulate blood sugar levels, stimulates wound healing, and produces growth hormones
Isoleucine.
The last of the three BCAAs, isoleucine is involved in muscle metabolism and is heavily concentrated in muscle tissue. It’s also important for immune function, hemoglobin production, and energy regulation
Lysine.
Lysine plays major roles in protein synthesis, calcium absorption, and the production of hormones and enzymes. It’s also important for energy production, immune function, and the production of collagen and elastin
Histidine.
Your body uses this amino acid to produce histamine, a neurotransmitter that is vital to immune response, digestion, sexual function, and sleep-wake cycles. It’s critical for maintaining the myelin sheath, a protective barrier that surrounds your nerve cells
