How Many Essential Amino Acids (EAAs) Are There?

How Many Essential Amino Acids Are There? EndurElite Chief Endurance Officer Matt Mosman discusses the 9 essential amino acids (EAAs), why they are considered essential, and why they are important.

Essential Amino Acids Fast Facts:

Ever wonder how many essential amino acids (EAAs) there are and why exactly they are essential?

  • Out of the 20 amino acids, 9 cannot be produced by the body and must be consumed through your diet or supplementation.
  • This is why they are considered ESSENTIAL.
  • The 9 essential amino acids are leucine, iso-leucine, valine (all BCAAs), lysine, histidine, phenylalanine, methionine, threonine, and tryptophan.
  • Essentials amino acids are important because they serve as the "building blocks" for muscle protein.
  • They are also are what makes a protein a "complete" protein.

I want you to finish this sentence. “Amino acids are the…..” If you paid attention in your high school biology class you easily filled in the blank with “building blocks for protein.” Just like a jigsaw puzzle is made up of tiny pieces that make a whole, proteins are made up of multiple amino acids connected in long chains. These long chains of amino acids come in a variety of shapes and sizes, all of which can be transformed into bigger protein shapes.

On the surface, all the amino acids might seem the same to you but I assure you they are all a little different. In this article, we will discuss how many amino acids there are, what amino acids do, the different type of amino acids, natural sources of amino acids, and the difference between essential and non-essential amino acids.

How Many Amino Acids Are There And What Do Amino Acids Do?

There are a total of 21 amino acids (we’ll discuss each one later). Some of these amino acids can be made by the body while others need to be consumed through food or supplementation.  Think the only reason you need protein is for muscle growth? WRONG. Protein is also used to make enzymes, hormones, and other chemicals in the body. You need it for your body to function. MIND BLOWN!!!!!!

What Are the 21 Amino Acids?

The 21 amino acids are:

  1. Isoleucine
  2. Histidine
  3. Leucine
  4. Methionine
  5. Lysine
  6. Phenylalanine
  7. Tryptophan
  8. Threonine
  9. Valine
  10. Alanine
  11. Arginine
  12. Asparagine
  13. Aspartic Acid
  14. Cysteine
  15. Glutamic Acid
  16. Glutamine
  17. Glycine
  18. Proline
  19. Serine
  20. Tyrosine
  21. Selenocysteine

Furthermore, these 21 amino acids can be classified as essential, non-essential, and conditionally essential. Let’s discuss each.

What Are Essential Amino Acids?

Essential amino acids are considered “essential” because the body cannot produce them.  They must be consumed through a regular diet or supplementation and most importantly you can’t survive without them.  Additionally, any protein that is considered to be “complete” must contain all the essential amino acids.

The 9 Essentials Amino Acids & What They Do

There are a total of 9 essential amino acids. These are:

  1. Leucine - Serves as the trigger for muscle protein synthesis...the physiological process of muscle repair and recovery. This is why it is often referred to as the “main” amino acid.
  2. Iso-leucine - Also helps stimulate muscle protein synthesis but to a lesser degree. Also helps glucose uptake during exercise.
  3. Valine - Helps decrease fatigue during exercise by competing with tryptophan in the brain. May also create stronger muscular contractions and enhance muscular endurance.
  4. Lysine - Helps covert fatty acids into energy, contributes to muscle protein synthesis, and plays a role in the formation of collagen.
  5. Histidine - Needed for the maintenance of sheaths that protect nerves (myelin sheaths) and combines with beta-alaine to form carnosine.
  6. Threonine - Promotes proper protein balance in the body and keeps connective tissue strong and elastic.
  7. Methionine - Precursor to protein synthesis and essential for the production of creatine.
  8. Phenylalanine - Increases the production certain neurotransmitters that are critical for muscle movement and activation.
  9. Tryptophan - Required to synthesize proteins and neurotransmitters like serotonin and may positively affect pain perception.

These first 3 essential amino acids are collectively referred to as the branched chain amino acids (BCAAs). They are the most important amino acids as it relates to muscle repair.

Which Foods Provide All The Essentials Amino Acids

Some examples of foods containing all the essential amino acids (EAAS)

  • Beef, Pork, Turkey
  • Chicken, Eggs
  • Milk, Yogurt, and Cheese
  • Fish and Other Seafood

What Are Non-Essential Amino Acids?

Non-essential amino acids are ones that can be produced by the human body and thus are not essential to the human diet. Although not “essential” these amino acids also play important roles in the body besides building proteins.

The 6 Non-Essential Amino Acids And What They Do

There are a total of 6 non-essential amino acids. These are:

  1. Alanine - Helps convert glucose into energy and eliminates toxins from the body.
  2. Aspartic acid - Promotes the transport of minerals to the cells and plays a role in metabolism.
  3. Asparagine - Plays a key role in the synthesis of glycoproteins and is essential for neuron development.
  4. Glutamic Acid - A chemical messenger amino acid that supports brain function.
  5. Serine - Assists in the formation of phospholipids and the functioning of RNA and DNA.
  6. Selenocysteine - Plays a role in oxidation-reduction reactions.

What Are Conditionally Essential Amino Acids?

Conditionally essential amino acids are “conditional” because their formation can be limited under certain special conditions, such as severe catabolic distress or being born prematurely.

The 6 Conditionally Essential Amino Acids And What They Do

There are a total of 6 conditionally essential amino acids. These are:

  • Arginine - Plays a role in cell division and immune function. Also, is a precursor to nitric oxide production.
  • Cysteine - Assist in the building of white blood cells and skin.
  • Glycine - Critical for a healthy digestive system and helps regulate the formation of bile.
  • Glutamine - Helps remove excess ammonia from the body and can be converted to glucose.
  • Proline - Essential component of collagen and vital for proper joint and tendon function.
  • Tyrosine - Provides the building blocks for neurotransmitters and hormones responsible for regulating metabolism.
  • The Bottom Line On Amino Acids

    As you can see from the above information, amino acids serve many different roles in the body besides just building muscles via protein creation. As a general recommendation, and in order to get enough amino acids on a daily basis, you should consume adequate amounts of protein on a daily basis.  General guidelines are:

    • Inactive Adults: 0.8 grams of protein per kilogram body weight daily.
    • Endurance Athletes: 1 - 1.6 grams of protein per kilogram body weight daily.
    • Strength/Endurance Athletes: 1.4 - 1.6 grams of protein per kilogram body weight daily.
    • Strength Athletes: 1.6 - 2 grams of protein per kilogram body weight daily.