Amino Acids: What Are They and Why Are They Important?

by Elena, Move to Root

There are 20 letters in the alphabet. The protein alphabet, that is.

Or maybe your 9^th-grade biology teacher referred to them as building blocks of protein? Cars on the protein train? Links in the protein chain? Whatever your metaphor, we’re all talking about the same thing—and it just so happens to be one of our very favorite topics: amino acids.

You’ve heard about them but may still wonder, ​“what are amino acids, exactly, and why do they get so much attention?” Maybe you’ve overheard a conversation in the gym and now you want to know about BCAAs and important amino acids for muscle growth? To get these questions answered, you’ve come to the right place. Keep reading for your ultimate guide to amino acids.

What are amino acids?

Amino acids are organic compounds that form chains to create proteins. Us humans use a set of 20 amino acids to form the thousands of proteins we need to properly function. Their specific roles depend on the unique amino acid sequence in their chains¹.

Although many relate amino acids to muscle growth, these small molecules are needed for far more than making gains. Amino acids also affect your energy levels, mood, immune system, and much more—but more on that later. First, let’s get comfortable with the primary categories and subcategories that make up the 20 amino acids: nonessential, essential, conditionally essential, and branched-chain amino acids (BCAAs).

Nonessential amino acids

Amazingly, the human body can make 11 amino acids on its own (when healthy—see more on this under conditionally essential amino acids)¹. These are classified as nonessential, and they include:

Although vital for health, your body does the heavy lifting on these—so you don’t have to fret about what foods contain them and how much you’re consuming each day. 

Essential amino acids

It is essential that you consume the essential amino acids through your diet because the body cannot produce them independently¹. The nine essential amino acids are:

It was once thought that every essential amino acid must be consumed at each meal for good health, but scientists have disproved this notion. The body can store amino acids and utilize them when necessary, making manual protein ​“combining” unnecessary. That said, many health professionals say it is important to consume each of the essential amino acids regularly. Without adequate essential amino acid sources in the diet, the body won’t be able to function properly¹.

Conditionally essential amino acids

So, we’ve classified all 20 amino acids as either essential or nonessential. Within these groups, there are some noteworthy subcategories. The first can be referred to as conditionally essential amino acids. These include amino acids such as: asparagine, cysteine, glutamine, glycine, proline, and tyrosine.²

As you can tell by their category name, these amino acids (although nonessential under standard ​“healthy” conditions) are essential in times of illness or major change, such as growth or pregnancy. That means your body may increase its demand for the conditionally essential amino acids when under metabolic change or physiological stress, making consuming these amino acids critical¹.

Branched-chain amino acids

Branched-chain amino acids (BCAAs) are named for their chemical structure and consist of leucine, isoleucine, and valine. What makes these three so special, you ask? Well, aside from their unique branched chains, these amino acids have been found to have the potential to increase muscle mass,³ prevent muscle breakdown,⁴ and reduce exercise fatigue.⁵ Hence, you may see them for sale at the gym, or next to protein powders for muscle enhancement at the store. 

Functions and benefits of amino acids

Each of the 20 amino acids required by us humans play a uniquely crucial role in keeping the body functioning properly. Here are some examples of why consuming all the amino acids is so important:

• Phenylalanine aids in the production of neurotransmitters such as dopamine, the ​“feel-good” neurotransmitter.⁶

• Lysine is involved in hormone and collagen production and can speed up wound healing.⁷

• Leucine can increase insulin response and helps regulate blood sugar levels.⁸

• Glutamine is the most abundant amino acid in the body, and when insufficient glutamine stores are available in the body, the immune system can suffer.⁹

• Glycine assists in nervous system regulation¹⁰ and becomes conditionally essential during pregnancy.¹¹

• Tryptophan is vital for serotonin production and assisting in the regulation of mood, appetite, and sleep.¹²

• Histidine aids in the production of histamine, which plays a starring role in immune system function. 

Best sources of amino acids

While it’s true that animal sources of protein contain all of the essential amino acids, emerging plant and fungi-based alternative proteins are becoming increasingly common, too. Here are some examples of plant proteins that contain all of the essential amino acids: 

• Amaranth

• Buckwheat

• Hemp seeds

• Soy

• Quinoa

Another example is Fy Protein™. Our nutritional fungi protein contains not only all of the essential amino acids but all 20 amino acids, making it a superb protein source for vegans, vegetarians, flexitarians, and carnivores alike!

PDCAAS

It’s not only about the amount and type of amino acids to check for when choosing protein sources. Something else to consider is the Protein Digestibility Corrected Amino Acid Score or PDCAAS. The World Health Organization uses this number to measure protein value in human nutrition.¹³ The higher the score, the higher the food is in protein value. In other words, certain protein foods may be an abundant source of amino acids, but that doesn’t mean your body will absorb all of them. For example, beef has a PDCAAS of 0.92; Fy protein, 0.91; pea protein, 0.82; and hemp protein, 0.66.¹⁴ The higher the score, means that your body has an easier time absorbing the amino acids present in beef and Fy protein rather than, say, hemp protein (this doesn’t mean hemp protein should be avoided—it’s still a great choice! It will just take more of this source to absorb the same amount of amino acids compared to a protein with a higher score). 

The bottom line

Many health scientists conclude that supplementation of amino acids is unnecessary when adequate consumption can be met through diet alone¹⁵ , but amino acid supplements in the form of capsules, powders, and liquids are becoming increasingly popular today. For example, BCAAs added to protein powder are common among athletes and bodybuilders, and amino acids such as glutamine and tyrosine can be seen in capsule form and are popular among some health and wellness enthusiasts.

But regardless of your lifestyle or preferred diet, every physiological feature of all living organisms requires amino acids to both thrive and survive.¹⁶ Pretty impressive, no? These tiny compounds are great for building a chiseled six-pack, but they are also needed for hormone production, immunity, mood regulation, quality sleep, and so much more. While animal protein contains all of the essential amino acids, many high-quality alternative proteins do, too—and they’re getting more accessible every day. Not only does Fy protein contain all 20 amino acids, but its PDCAAS is also impressively high, ensuring optimal digestibility and utilization.