Protein explained

protein-cartoonProtein – Protein is, I would say, the most important nutrient second to water. The word protein is actually a Greek word meaning “of prime importance” and they weren’t wrong either. Protein is made up of amino acids and they are said to be the “building blocks” of all proteins.

There are 20 amino acids in total and nine of these amino acids are what we consider to be essential amino acids (EAA). We humans can not synthesize them ourselves so they must be obtained externally via diet. The essential amino acids are:

  • Histidine
  • Isoleucine
  • Leucine
  • Lysine
  • Methionine
  • Phenylalanine
  • Theronine
  • Tryptophan
  • Valine

The other 11 amino acids are know as nonessential because the human body can synthesize them. The nonessential amino acids are:

  • Alanine
  • Arginine
  • Asparagine
  • Aspartic Acid
  • Cysteine
  • Glutamic Acid
  • Glutamine
  • Glycine
  • Proline
  • Serine
  • Tyrosine

Luckily we get most of these essential and non essential AA’s just by eating our normal diets as pretty much all of our foods contain amino acids. Some foods like vegetables, breads, lentils etc contain non-essential AA’s and may only contain some essential AA’s, this is called an incomplete protein which wont build muscle. Foods like meat however contain both non-essential and all of the AA’s which is a complete protein source and can be used to build muscle. The difference in foods can mean the difference between having a meal that has the materials to build muscle and one that doesn’t.

Basically you need all 9 essential amino acids in the mix for it to be a complete protein and only complete proteins have muscle building potential. This is why vegans can end up protein deficient, most non animals foods they eat are of poor protein quality and incomplete sources of protein. This does not mean vegans are nutritionally doomed though, it just means you need to be a bit more savvy when it comes to food choices and be sure to pick the right the right foods. You can also combine 2 or more incomplete protein sources to increase the AA profile giving you complete protein but there are still some great vegan protein sources out there. Quinoa, soy/tofu, mixed nuts, seeds and many vegan based protein powders such as pea, hemp and rice protein powders are the best complete sources of protein and should be eaten frequently to make up for the lack of protein choices.

When protein is consumed various enzymes such as protease, pepsin and trypsin (and many others I don’t have the knowledge to name) are all are released at certain points after ingestion to help break it down. The amino acids are broken down in the stomach into single amino acids then are absorbed through the walls of the small intestine where they enter the blood stream. The blood then carries the amino acids to  the rest of the body to rearrange into human proteins and use in  building its structure. Each part of the “machine” of digestion must  work properly in order for protein to be broken down into useful  amino acids.

From the digestion of protein the body has all the amino acids broken down, circulating in the blood and lymphatic system and is taken from this circulating supply of amino acids as and when needed. This continuous circling supply of amino acids is what’s known as the amino acid pool. This pool of amino acids can be used for energy or cell repair depending on dietary protein and energy intake. When undertaking any fitness program it’s essential you increase your protein intake to meet the added stress your now placing on your body so you body has the necessary building blocks to repair and recover.