Remember the old parlor game of building a house of playing cards and then trying to remove a single card without collapsing the whole construction?
The image or a house of cards gives a useful illustration of how Amino Acids – the molecular building blocks of protein – contribute the “cards” to the full construction that is a healthy body. Like the house of cards, our bodies depend on having a “full deck” in order to maintain balance in all the hundreds of daily functions.
Proteins Make Up The Body’s Substance
Next to water, protein is the most plentiful material in our bodies. Proteins make up 20% of our total weight. Muscles, skin, hair, eyes, nails and our numerous internal enzymes are chiefly made of proteins. Body tissue repair, growth and the manufacture of infection-fighting antibodies are all dependent on the quality as well as the quantity of our protein – and therefore our amino acid – intake.
Protein foods, if we are vegetarians, come mainly from meat, fish, eggs and dairy products. The grains, beans, peas and nuts preferred by vegetarians are also good protein sources and owing to their high fiber/low-fat content they should be given more space in our dietary selection of protein building blocks. Vegetable source protein needs careful selection, however, to guarantee “the full deck” of amino acids. We will see how to do this in a moment.
20-plus Aminos = One Complete Protein Food
If, like a chemical magician, we took a protein tissue sample from the body and made its cell walls disappear so all we could see were its protein bits, we would find 22 different amino acids – one for each building block of the protein. These amino acids have names like “tyrosine,” “proline,” “lysine,” etc. (you’ll note that all the names aid in “-ine” that is a clue we are looking at a protein molecule). The total 22 amino acid building blocks present in our magical tissue sample tells us that our protein is “complete” – literally a “fell deck.”
A “complete protein” is thus able to nutritionally sustain life, promote growth and repair damaged tissues. Meat, eggs, fish, poultry and dairy products are examples of “complete proteins.” There is, technically speaking, no such thing as a “perfect” protein; however, the above foods – especially eggs – come as close as we’re likely to find.
Grains, beans, peas and nuts or seeds are called “incomplete proteins” because their amino acid building blocks are not the full deck – one or more of the requisite 22 are missing.
Nearly all vegetable source protein foods are deficient in one or more of the 20-plus needed to characterize a “complete” protein. The exception to this is the plant “Spirulina” which does contain all the required aminos.
Essential Versus Non-Essential Amino Acids
So, to ensure we get all the protein building blocks in our diet, we need to pay attention to the quality of the protein foods we eat. If our dietary protein comes from vegetable sources – the grains, nuts, beans foods – then we need to combine several different types of plant foods with their correspondingly different amino acid building blocks in order to get the “full deck”. This deliberate pairing-up of vegetable protein foods to make complete protein foods is called “complementary protein food combining” by dedicated vegetarians and is good sound nutrition.
Of the 20-plus different amino acids that build protein, our bodies can manufacture about half from the raw materials in a good varied diet. That leaves about 10 or so remaining necessary amino acids that we cannot manufacture and therefore must specifically consume them each day. These critical 10 or so aminos are referred to as “Essential Amino Acids” (like those “essential fatty acids” Omega 3 and Omega 6 that we have to eat each day.)
These Essential Amino Acids include Arginine, Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Threonine, Tryptophan, and Valine. We have fully listed the Essential Aminos here because they can have dramatic effects on our health if even one is chronically missing from our diets. Some of these Essential Amino Acids also have special therapeutic applications if we take them as a supplement.
Protein Foods As Fuel-foods
Proteins that are utilized as “feel” for energy by the body are less efficient than if carbohydrate foods (sugars, veggies, fruits, grains) are available for use. Protein source feel (stored as our muscle tissue) is only called into play if our dietary intake of carbohydrates is inadequate. This is why in cases of true starvation when the body’s stores of carbohydrates (stored as body fat) are gone the next tissue to be “eaten” is our own muscle tissue and the body suffers wasting.
Amino Acids do not “store” in the body the way fats do and can only provide energy through the destruction of protein tissue. For this reason, it is very important to eat enough protein every day. You cannot eat only grain foods one day and seed foods the next and then trust to getting the “full deck” of all the necessary amino acids eventually. Each and every day the body requires Complete Proteins to go about its maintenance and repair programs.
Daily Protein Requirements
Our daily need for protein is dependent on many health factors including our relative age (young growing bodies need more protein, the elderly less protein), the quality and digestibility of the protein roods, and stress (both physical and mental). According to authorities, the recommended average daily protein intake for most people is 0.8 grams per kilo of ideal body weight. Pregnant and nursing mothers need an extra 30 and 20 grams respectively.