Amino acids, often referred to as the building blocks of proteins, are compounds that play many critical roles in your body. They’re needed for vital processes like the building of proteins and synthesis of hormones and neurotransmitters. Some may also be taken in supplement form for a natural way to boost athletic performance or improve mood.
They’re categorized as essential, conditionally essential or nonessential depending on several factors. Amino acids are organic compounds composed of nitrogen, carbon, hydrogen and oxygen, along with a variable side chain group.
Your body needs 20 different amino acids to grow and function properly. Though all 20 of these are important for your health, only nine amino acids are classified as essential. These are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine. Essential amino acids can’t be made by your body and must be obtained through your diet.
When you eat protein, it’s broken down into amino acids, which are then used to help your body with various processes such as building muscle and regulating immune function .
There are several nonessential amino acids that are classified as conditionally essential.
An amino acid that can be made by humans and so is not essential to the human diet. There are 11 nonessential amino acids: alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine, and tyrosine.
These are considered to be essential only under specific circumstances such as illness or stress.
For example, although arginine is considered nonessential, your body can’t meet demands when fighting certain diseases like cancer.
That’s why arginine must be supplemented through diet in order to meet your body’s needs in certain situations.
The nine essential amino acids perform a number of important and varied jobs in your body.
Though amino acids are most recognized for their role in muscle development and repair, the body depends on them for so much more. That’s why essential amino acid deficiencies can negatively impact your entire body including your nervous, reproductive, immune and digestive systems.
Foods that contain all nine essential amino acids are referred to as complete proteins.
Complete protein sources include:
Soy, quinoa and buckwheat are plant-based foods that contain all nine essential amino acids, making them complete protein sources as well .
Other plant-based sources of protein like beans and nuts are considered incomplete, as they lack one or more of the essential amino acids.
However, if you’re following a plant-based diet, you can still ensure proper intake of all essential amino acids as long as you eat a variety of plant proteins each day.
For example, choosing a variety of incomplete proteins such as beans, nuts, seeds, whole grains and vegetables can ensure that your essential amino acid needs are met, even if you choose to exclude animal products from your diet.