You’ve probably heard of BCAAs and EAAs, but what exactly are they and are they important? In a multi-part blog series we’re going to explore this topic.
First, let’s start at the top of this chain and provide some helpful definitions.
Protein: A macronutrient, structurally made up of many amino acids linked together by peptide bonds. Often in nutrition when we are talking about proteins we are referring to a food source.
Peptides: A structure smaller than a protein made up of amino acids connected by peptide bonds
Amino Acids: The individual building blocks, able to be absorbed into the bloodstream for bodily use.
And now that we have broken down proteins to amino acids, let’s categorize amino acids
Essential amino acids (EAAs) are a group of amino acids that our bodies cannot synthesize in adequate quantities alone, so they must be obtained through the diet.
Non-essential amino acids are amino acids that our body can make
Conditionally essential amino acids are a group of amino acids that usually do not require dietary sourcing, except for times of illness or stress.
And now that you can see all categorization of the amino acids, we can finally get to EAAs vs. BCAAs
EAAs as noted above is the commonly used abbreviation for Essential Amino Acids.
BCAAs is the commonly used abbreviation for Branched Chain Amino Acids. These amino acids have a aliphatic side-chain with a branch
As this diagram illustrates BCAAs are a subset of EAAs.
Now that we have some definitions, let's run through, in simple terms, of how this actually works in your body everyday.
First, you consume a protein food, like chicken. Digestion starts in your oral cavity with your teeth starting to physically break down the food.
Next, in your stomach denaturing, or unfolding, of the protein occurs with hydrochloric acid. And pepsin enzymes start to break down the peptide bonds in the protein into smaller peptide structures.
Then, in your small intestine, enzymes like chymotrypsin, trypsin, and proteases act to further break down these peptides into very small chains of two to three amino acids.
Lastly, in your small intestine, enterocytes (intestinal cells) absorb these small amino acid chains and finalize the breakdown into individual amino acids where they can finally be absorbed into the bloodstream and transported to the liver for use.
Now that we hopefully have a better understanding about how protein is broken down, and the categorization of amino acids, we can start to dive into why amino acids are so important for our bodies in part 2 of this series.
References:
Callahan, Alice, et al. “Protein Digestion and Absorption.” Openoregon.pressbooks.pub, 2020, openoregon.pressbooks.pub/nutritionscience/chapter/6d-protein-digestion-absorption/.
Lopez, Michael J., and Shamim S. Mohiuddin. “Biochemistry, Essential Amino Acids.” PubMed, StatPearls Publishing, 2022, www.ncbi.nlm.nih.gov/books/NBK557845/.
MedlinePlus. “Amino Acids: MedlinePlus Medical Encyclopedia.” Medlineplus.gov, 2017, medlineplus.gov/ency/article/002222.htm.
National Research Council (US) Subcommittee on the Tenth Edition of the Recommended Dietary Allowances. “Protein and Amino Acids.” Nih.gov, National Academies Press (US), 2013, www.ncbi.nlm.nih.gov/books/NBK234922/.
Nie, Cunxi, et al. “Branched Chain Amino Acids: Beyond Nutrition Metabolism.” International Journal of Molecular Sciences, vol. 19, no. 4, 1 Apr. 2018, p. 954, www.mdpi.com/1422-0067/19/4/954/htm, https://doi.org/10.3390/ijms19040954.
Watford, Malcolm, and Guoyao Wu. “Protein.” Advances in Nutrition, vol. 9, no. 5, 27 July 2018, pp. 651–653, www.ncbi.nlm.nih.gov/pmc/articles/PMC6140426/, https://doi.org/10.1093/advances/nmy027.
