Amino acids are critically important to all aspects of human physiology -- they are indeed the building blocks of life!
To understand what exactly an amino acid is, let’s go over some basic chemistry first. Amino acids contain a nitrogen component and one or more of a group known as a carboxyl group. The take away from this is these components are crucial ingredients for building parts of the body, making them incredibly important for life and health.
Amino acids are groups of organic compounds and contain one or more amino groups, which is how we determine which type of amino acid it is. There are twenty amino acids that can be differentiated by three groups: essential amino acids, conditionally essential amino acids, and non-essential amino acids.
Now let’s dive deeper and take a look at each of these groups.
Non-Essential Amino Acids
Eleven of the twenty amino acids are considered non-essential, meaning they are not required in our diet to survive. Though you can consume these amino acids, non-essential amino acids are also produced within the body from other amino acids. The amino acids included in the non-essential group include: alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine, and tyrosine.
Essential Amino Acids
The remaining nine amino acids get their name due to the fact that we cannot manufacture them within our bodies. We need to consume them through our diet.
If for some reason you were starving, your body would start to break down muscle and tissue within the body to produce non-essential amino acids, but cannot make the essential amino acids. Now, say you are consuming enough calories to keep you alive, but missing one or more of the essential amino acids from your diet entirely, you could become very sick as an important bodily function is not being nutritionally supported.
These nine essential amino acids are: histidine, isoleucine, leucine, valine, lysine, methionine, phenylalanine, threonine, and tryptophan. If you have ever heard or seen the term complete protein, this means the product contains all nine of the essential amino acids.
Conditionally Essential Amino Acids
Conditionally essential amino acids are very different from the first two groups of amino acids as they vary from individual to individual. A non-essential amino acids can become essential for an individual based on a specific lifestyle, diet or medical condition.
Therefore, an individual may require additional consumption of one or more of the eleven non-essential amino acids from food, if the amino acid(s) is not being naturally produced at the level the individual needs.
For example, let’s look at an Olympic athlete. They would require more of the amino acid arginine than an average individual due to their intense training. This is due to the fact that arginine changes into nitric oxide which allows for the blood vessels to relax and improves circulation, supporting the healing of muscles.
Breaking Down Amino Acids in the Body
So how do these amino acids break down in the body?
If you were eating a piece of chicken there is a protein unfolding process in the stomach, which breaks down the protein’s polypeptide chains into smaller peptides, and from there into amino acid chains, and finally into single amino acids. This process starts in the stomach over a period of time and continues in the small intestine. The length of this process depends on the type of food that was consumed and what else was consumed with it.
Once the unfolding process is complete, digestion continues, breaking down the polypeptide chains into amino acids. This concludes in the first part of the small intestine known as the duodenum. It is at this point the amino acids start to be absorbed as they continue throughout the rest of the small intestine (including the duodenum, jejunum, and ileum). Depending on each food, this process occurs over a minimum of three hours.
Moving away from whole foods, let’s take a look at amino acids consumed as a supplement. Branched-chain amino acids (BCAAs) -- the three essential amino acids required for building muscle -- are quickly utilized by the body because they do not require that unfolding process in the stomach that turns protein into smaller polypeptide chains, and the proteolytic enzymes of the small intestine that converts these into single amino acids. Instead, they are passed directly into small intestine where they can be absorbed.
Amino acid absorption can be negatively affected if you’ve consumed a food that you are intolerant/allergic to. For example, a person with an unknown gluten intolerance ingests a chicken and pasta meal. Chicken is a complete protein (with all nine essential amino acids) but the pasta is full of gluten. While being digested, the body will eliminate the gluten along with anything consumed with it -- meaning the individual is not fully digesting or absorbing the protein, amino acids and nutrients they thought they did. This process, if repeated, is another cause when a non-essential amino acid could become a conditionally essential amino acid for a specific individual.
Amino Acids in your Diet
As much as you think the more the merrier, the truth is if you are ingesting or making enough of an amino acid, you don’t need anymore. Therefore, if you are following a balanced diet with the appropriate amino acids, including sufficient amounts of the essential amino acids, you do not need to supplement these. Now saying that, as mentioned earlier, there are individual cases. If you are a professional athlete you will need more of certain amino acids, such as arginine and leucine, than the average person. Therefore for your individual case, be sure to include a sufficient amount of your conditionally essential amino acid(s) in your diet as well.
If you follow a omnivorous diet be sure to eat a wide variety of whole foods from both animal and plant sources. You are not going to get the beneficial amount of arginine you would receive from plant-based protein foods in any animal-based food. Balancing both is ideal for optimal amino acid levels.
As previously mentioned, animal proteins are complete proteins containing all nine essential amino acids and all of the conditionally essential amino acids, so all you need to do is have a variety of them! Don’t just eat chicken as your protein source - add in eggs, fish, red meat, etc.
In terms of plant-based sources, with the exception of a few sources such as pumpkin seeds, plants that are high in protein are typically incomplete sources (they don’t contain all nine essential amino acids). Therefore, you must ensure you have a varied diet of plant-based proteins daily.
Whether you are following a omnivorous, vegetarian or vegan diet, it is always recommended to consume the highest quality NSF Certified for Sport protein supplement that you can find. Do your research to ensure it contains all of the essential, non-essential, and conditionally essential amino acids.
As a final recommendation, combining a variety of protein sources is best for optimal health. For more information on protein and absorption rates click here.