Protein is an important part of every cell in your body. To better understand the protein you add to your diet, you need to explore its building blocks: amino acids. Depending on whom you ask, there are about 20 to 22 standard amino acids. Although they all benefit the body, they are not all dietary necessities. Amino acids that your body needs that cannot be synthesized naturally within the body are known as “essential amino acids.”
Before we dig in and explore these critical components, it’s important to note that lists of essential amino acids vary by age and reference. For example, histidine is typically considered an essential amino acid for infants but not for people over the age of 10. And since some amino acids can be produced from others, it can be difficult to differentiate between essential and non-essential amino acids. For example, in the essential (also called indispensable) amino acid scoring patterns of the Institute of Medicine (IOM) and the Food and Agriculture Organization (FAO), cysteine is added to methionine and tyrosine is added to phenylalanine. You must also combine these amino acids (methionine + cysteine, phenylalanine + tyrosine) when calculating a Protein Digestibility Corrected Amino Acid Score (PDCAAS).
All this to say, it can be difficult to pin down facts when discussing essential amino acids. Depending on whom you ask, there are either eight or nine essential amino acids.
Essential Amino Acids
What are the essential amino acids?
As we mentioned briefly above, our bodies can make some amino acids from scratch (non-essential amino acids). Others (essential amino acids) must be obtained through food or dietary supplements. Adults require eight essential amino acids (also called indispensable amino acids), while infants require nine. The body requires these amino acids on a regular basis to maintain good health, because they cannot be stored for later use.
- Isoleucine (I)
- Leucine (L)
- Lysine (K)
- Methionine (M) + Cysteine (C)
- Phenylalanine (F) + Tyrosine (Y)
- Threonine (T)
- Tryptophan (W)
- Valine (V)
- Histidine (only required by infants)
Each essential amino acid serves a different function. For example, leucine assists with the healing growth of tissue (including muscle tissue), and isoleucine raises your energy levels.
Why do we combine methionine and cysteine? What about phenylalanine and tyrosine?
In many charts, you will see methionine and cysteine combined and phenylalanine and tyrosine combined. Although these are all separate amino acids, we address them in pairs because the body can convert methionine into cysteine and phenylalanine into tyrosine. Because of this, some may only consider methionine and phenylalanine essential.
Why do our bodies need essential amino acids?
A lack of essential amino acids leads to a protein deficiency. Because proteins play such an important role in the body and influence every part of it – from the organs to the skin to the blood – a deficiency of essential amino acids can cause significant damage. For example, it can harm the brain, the immune system, the kidney function, and the growth of skin and hair. We need protein to live.
When your diet lacks essential amino acids, your body will look for these crucial components in your muscle tissue. Thus, muscle degradation is often one of the first symptoms noticed by people suffering from a lack of essential amino acids. Other symptoms include weakness, fatigue, changes in hair/skin texture, and decreased immune response. Protein is especially crucial to the diets of athletes, because it helps the body repair and strengthen muscle tissue (as well as bone, cartilage, skin, and blood).
Although vegetarians and vegans may need to pay more attention to the variety of protein in their diets in order to avoid a lack of amino acids, protein deficiency is uncommon. It most commonly occurs as a result of poverty and malnutrition, especially in parts of the world with limited food supplies.
What are branched-chain amino acids?
Amongst the essential amino acids listed above, you will find three branched-chain amino acids (BCAA): leucine, isoleucine, and valine. The name refers to the chemical structure of the amino acids, as they all contain a central carbon atom bound to three or more carbon atoms, which form “branches.”
Some bodybuilders encourage the consumption of BCAAs, claiming that they can increase your body’s ability to recover after a workout. In addition, some say they provide a boost in physical stamina, a decrease in muscle breakdown, and reduced inflammation. Supplements containing BCAAs are often advertised to bodybuilders.
How can I ensure I obtain enough of all the essential amino acids regularly?
As organizations disagree, studies produce varying results, and the numbers have shifted over the years, it is difficult to estimate the daily minimum intake requirements of essential amino acids. In addition, it is important to note that requirements vary depending on your age, and they may vary due to pregnancy and lactation (source).
However, you can obtain sufficient amounts of all of the essential amino acids simply by eating a healthy, balanced diet. They are found in both animal and plant proteins. Since proteins vary in their amino acid composition, explore your preferred protein sources to ensure they contain the amino acids you need. When a source of protein contains all of the essential amino acids a human needs, it is called a “complete protein.”
You can also ensure that essential amino acids are in your diet by consuming a protein supplement. For example, if you’re looking to add a boost of protein to your diet, try CHiKPRO®, a nutritious chicken protein isolate powder. As you can see in the profile below, CHiKPRO® offers all of the essential amino acids your body requires, as well as conditionally essential amino acids and non-essential amino acids.
Versatile and easy to use, this protein supplement contains 25 grams of protein in each 30-gram scoop! You can use it in pizza, waffles, smoothie, frittatas, and many more delicious recipes. Plus, it is non-allergenic, dairy-free, and gluten-free. To learn more, please visit the CHiKPRO® website.