A Quick Guide to Amino Acids

What are amino acids?

Amino acids are commonly referred to as the “building blocks of protein”.  There are 20 amino acids.  These amino acids bond together to form a protein.  Like Legos combing together to build a toy house, the volume of amino acids and the way in which they bond determine the shape and function of the resulting structure.   

Amino acids are classified as being either non-essential or essential.  There are 11 non-essential amino acids.  As the name would suggest, non-essential amino acids can be naturally produced by the body so they are “not essential” to the human diet.  Essential amino acids, on the other hand, are unable to be naturally produced by the body so they must be obtained from our diet.  There are 9 essential amino acids.  Of these 9 essential amino acids, three belong to a special group called branched chain amino acids (BCAAs).  The BCAAs (isoleucine, leucine, and valine) have special properties that allow them to be integral components of multiple bodily functions.  They account for approximately 50% of muscle protein, as well as play a role in metabolic functions, protein synthesis, energy production, neurotransmitter production, glucose metabolism, immune responses, insulin sensitivity, liver regeneration, and inhibition of free radical production.  The details regarding this incredibly productive subset of amino acids are discussed later in this article. 

What happens when we consume amino acids?

Since each protein molecule contains 20 amino acids, consuming protein is an incredibly efficient way to consume all of the dietary amino acids at once.  However, these protein molecules are relatively large structures (relatively speaking). The body needs to break them down into smaller chunks in order to transport them throughout the bloodstream to their appropriate locations where they can get to work.  Thus, upon consumption of protein, our bodies break down this molecule into smaller portions like peptides (small groupings of amino acids) or into individual amino acids.  These can then be transported and used to power functions within the body. Since amino acids power a wide variety of functions in the body, the amount in circulation (free amino acids) is constantly changing in order to meet our body’s demands.

What causes amino acid levels to change?

The amount we consume (dietary intake), de novo synthesis (the synthesis of complex molecules from simple molecules), and protein turnover from tissues all increase the number of free amino acids in circulation.  Excretion, oxidation, non-protein pathways, and tissue protein synthesis all draw amino acids out of circulation and decrease the overall amount that we have in flux at any given time. In this way, dietary protein intake, amino acid composition, protein digestibility, gastrointestinal tract digestion and absorption, and protein demand all influence our amino acid levels.

Where can I find dietary amino acids?

Since protein is a grouping of amino acids, protein in the food and drinks we consume is a great place to find a high concentration of amino acids.  However, individual amino acids are also present in many foods and drinks.  In this way, we can pick and choose which amino acids fit our specific needs and plan our diet accordingly. This may be the case for people who follow specific dietary restrictions or diets.  Vegans, for example, can easily consume an abundance of the amino acid methionine since it is prevalent in many grains.  However, grains have a very low lysine content.  Thus, individuals who are on a vegan diet may make a conscious effort to consume foods that have a high lysine concentration, like legumes. 

 Paying attention to specific amino acids is not just for those with specific diets.  We may also choose to consume more, or less, of an amino acid because we want to benefit from the work that the amino acids do within the body.  Leucine plays an important role in the regulation of protein synthesis and metabolic functions.  Thus, someone who wants to optimize their metabolic health may want to make sure they are consuming adequate leucine levels in order to assist in stabilizing their blood sugar. Likewise, athletes and active individuals may want to consume leucine in order to enhance the growth and repair of muscle tissue.

How many amino acids do I need?

While this question is certainly valid, the answer is not straightforward.  Amino acid and protein needs vary.  Let us start with the larger molecule, protein. The Academy of Nutrition and Dietetics guideline for healthy sedentary adults currently recommends 0.8 g of protein per kg of body weight.  However, recent researchers have determined that this volume may be insufficient for many individuals.  Protein needs increase with exercise, pregnancy, age, and illness.  Athletes and active individuals need additional protein in order to build and repair muscle to enhance performance.  Pregnant women need to promote the appropriate growth of tissues and organs.  When compared to their younger counterparts, older adults are less responsive to low doses of amino acid and protein intake.  In order to preserve muscle mass (which prevents sarcopenia) and help maintain energy balance, healthy adults over 65 years should increase their protein intake.  Older individuals that have had a health setback have an even greater dietary protein need. Illness is another factor that contributes to increased demand.  Branch chain amino acids and proteins contribute to the proper functioning of our immune system, which becomes even more important when we become ill.   

When it comes to individual amino acids, our needs also fluctuate due to our stage of life and lifestyle choices.  For many of us, consuming the appropriate amount of dietary protein will include a high enough volume of each amino acid to satisfy our amino acid needs.  However, there can be value in paying attention to specific amino acids in order to target specific physiologic effects (like the vegans, athletes, and health-conscious individuals we mentioned above). 

What happens if I consume too many amino acids?

Amino acids, and proteins, that exceed our needs are degraded and then excreted in our urine.  The part that remains after degradation (the keto acids) can be used as energy, converted to carbohydrates, or stored as fat.

What amino acids are in GOOD IDEA?

L-leucine, l-isoleucine, l-valine, l-threonine, and l-lysine monohydrate are the five amino acids included in each GOOD IDEA beverage.  The “l-“ prefix before each amino acid is an indicator of the way in which the parts of the molecule are arranged.  While this level of specificity is likely helpful for the chemistry enthusiasts amongst us, the rest of us simply need to know that “l-leucine” and “leucine” and functionally identical.  Thus, for the remainder of the article, we will refer to each amino acid by its root name and drop the prefix.

Leucine, isoleucine and valine are all BCAAs. The BCAAs impact metabolic functions such as glucose metabolism, glycogen synthesis, and insulin sensitivity. They also play a role in hormone production and protein synthesis. 

Threonine is an essential amino acid that aids in the maintenance of protein balance within the body. This protein balance is important for forming collagen, elastin, and tooth enamel. Threonine is both glucogenic and ketogenic, meaning that it can be converted into glucose or degraded directly into acetyl-CoA. Threonine is commonly found in cheeses, meats, fish, and poultry so individuals on vegan and vegetarian diets are susceptible to experiencing low levels of threonine. 

Lysine is an essential amino acid, meaning that it needs to be consumed throughout the diet.  Lysine is pivotal in the synthesis of collagen and cartilage. In addition, lysine plays a role in converting fatty acids into energy as well as helping to lower cholesterol.

How does this amino acid combination help to stabilize my blood sugar?

Amino acids slow gastric emptying.  This leads to a potential delay in glucose uptake and a ‘priming’ of the stomach that begins with the first sip of GOOD IDEA.  In this way, the consumption of specific amino acids has been shown to have a glucose-reducing effect. 

In addition to impacting glucose, this amino acid combination has also been shown to have an insulin-simulating effect. This results in a reduction in the postprandial glucose spike. Overall, these amino acids work together to prime the metabolism and provide more effective energy from the food we eat.  If you are interested in learning more about how each of these amino acids individually impacts our metabolic health, energy levels, and cravings, be on the lookout for our upcoming blogs on leucine, isoleucine, valine, threonine, and lysine.