Nutrition experts usually classify protein foods as complete, partially complete and incomplete. Lean meat (this includes gland meats, fish, and poultry), eggs, cheese, milk, millet and sunflower seeds are complete proteins, that is, they contain all 10 of the essential amino acids in correct proportions for maximum human nourishment. Whole grain products, soybeans, legumes and some nuts are classed as partially complete proteins meaning that their amino acids are not in balanced proportions to meet all body needs. However, these proteins are valuable “secondary” foods that should be generously included in every diet, particularly the whole grains; whether you use soybeans, legumes or nuts depends entirely upon your ability to digest them.
Vegetables, fruits and some grains are classed as incomplete proteins. Corn, for instance, contains only 7 of the 10 essential amino acids, while cabbage has even fewer. Yet by no means does this lessen the value of vegetables, fruits and whole grains in your diet; what “incomplete” means is that you would eventually starve to death trying to subsist entirely on these low-grade protein foods. But these incomplete proteins can be used to great advantage in a diet as supplements to the high-protein foods. (When I say that you would starve to death on a diet of fruits and vegetables, I can imagine you thinking, “But how about the vegetarians?” We will get to them a little further along. Like many other things, there is more to vegetarianism than meets the eye.) Each plant or animal food we eat contains a special variety of protein. For instance, vegetables contain types of protein that cannot be used by the human body, and which consequently are excreted by the kidneys. It may come as a surprise to many vegetarians to learn that less than half of the protein content of legumes can be utilized by the human body. Therefore, to obtain that safe surplus of protein so vital as a safeguard against deficiency diseases and premature aging, the vegetarian must consume at least three times more legumes in weight than would be necessary if he had no prejudices against animal proteins.
The closer a food protein resembles human protein, the more valuable it is for human nutrition. That is why we speak of high-grade proteins, meaning those foods that yield a maximum of protein nutrition in relation to the quantity consumed; and low-grade proteins, meaning those that furnish the body with only small amounts of usable protein. To illustrate: 100 grams of meat protein (high-grade) are far more valuable to human nutrition than 100 grams of carrot protein (low grade).A diet built around foods containing all 10 of the essential amino acids is a youth-protecting, health-promoting diet because it is a high-protein diet. If any doubt still lingers in your mind that a high-protein diet is imperative if you are to look younger and live out your allotted span of years (four score and more), let me remind you again that you are made of protein. Your blood plasma, red blood cells, hormones, muscles-in fact, every organ, fluid and tissue of your body (except urine and bile) are composed of amino acids.
As I often tell my lecture audiences: I wish the food chemists had been foresighted enough to christen these vital body chemicals with a name more descriptive, more appealing to the public than “amino acids.” I would like to re-christen them “youth restorers,” “body rebuilders” or “pep proteins.” For that is exactly what they are. Let me outline briefly what we know to be the direct effect of the 10 essential amino acids on the human body. Arginine is called the “fatherhood amino acid” because it comprises 80 per cent of all male reproductive cells (spermatozoa). When seriously lacking in the body, the sex instinct undergoes a marked decrease in men and women alike, causing impotency in the male. (Such a deficiency is often associated with early loss of sexual powers in men not conscientious about proper diet.)
Tryptophane is known to help ward off signs of premature aging such as cataracts, baldness and sex gland deterioration; it is also vital to the female reproductive organs. Your diet must contain this form of protein if vitamin A is to be properly utilized by your body, since a lack of sufficient tryptophane will cause symptoms similar to vitamin A starvation (eye disorders, easy susceptibility to colds and respiratory disorders and general weakness of the mucous membranes).Valine is directly related to the nervous system (one part of the body that really takes a beating as we grow older), and your diet must contain plenty of this protein if you want to avoid nervous disorders and digestive upsets. A person starved for valine becomes abnormally sensitive to touch and sound, and has trouble controlling his muscular movements. Histidine is principally a tissue repairer, and is active in producing normal blood supplies.
Lysine, when inadequately provided by the diet, has been linked with pneumonia, acidosis, headaches, dizziness and incipient anemia. It also has a direct influence on the female reproductive cycle. Methionine, if seriously lacking in the body, may cause hardening of the liver (cirrhosis), and nephritis (a serious kidney disease). It is also necessary to maintain normal body weight and aids in keeping a proper nitrogen balance in the body. (Nitrogen, a protein, is as vital to human life as it is to plant life.) Phenylalanine is closely linked with the body’s most efficient use of vitamin C. This means that not enough of this amino acid in the diet can result in susceptibility to infections, and to other diseases connected with insufficient vitamin C. The three remaining amino acids of the 10 essential ones are leucine, isoleucine and threonine. Their specific functions in the body have not as yet been completely explored by the
scientists, although it is known that these three amino acids play a vital role in helping maintain the body’s nitrogen balance, that is, the intake of proteins and the discharge of wastes and dead cells.
All 10 of these essential amino acids, plus the literally thousands of different protein combinations manufactured in your body from the original 10 (the red coloring matter in your blood, or hemoglobin as iit is called for example, may contain as many as 576 different amino acid groups) must do an uninterrupted job of building, repairing and replacing, if you are to remain a living animal. A red blood cell lives about thirty days. This means that every month a fresh, newly processed red blood cell must be recruited from your bone marrow into the bloodstream as a replacement for the defunct cell. The same is true of white blood cells. Kidney, bladder and intestinal cells are constantly being lost and must be replaced if these organs are to do a good job of removing wastes from your body. Skin, hair, fingernail and toenail cells are continually being destroyed and new ones must be provided. Internal and external secretions
(such as hormones, enzymes, digestive juices, tears, skin oils) must be produced without interruption in a healthy body, since these secretions are continuously being manufactured and produced each day in such extremely intricate body functions as digestion and sexual activity. I do not know whether you have ever thought of it this way or not, but the fact remains that the sole reason why you eat is to provide your body with energy, and to assure your cells of enough protein for all the vitally needed repairs and replacements.
You may think you eat because you “get hungry,” or because food tastes good, or because it is pleasant to share a meal with congenial companions. But actually you eat because your cells demand material (protein) for energy, and for repair work. A cell can not taste, and it is not convivial! Therefore, Nature tricks you by your taste buds into eating, so that vital energizing and restorative processes can go on without interruption. Please ponder this last fact for a few seconds-then remember it the next time you are undecided between a plate of high-starch foods such as white rice or macaroni, or a plate of body-rebuilding proteins like meat, eggs, cheese, milk or seed cereals. Dr. James S. McLester, well-known professor of medicine at the University of Alabama and one of the pioneers in treating nutritional deficiencies, says: “If a man would enjoy sustained vigor and would experience his normal expectancy … he must eat a liberal quantity of good protein.” Good protein means, of course, a complete protein-one containing all 10 essential amino acids. Meat, fish, poultry, cheese, eggs, milk and seed cereals are “good proteins.” Notice, please, that Dr. McLester specifies a “liberal quantity” of good proteins, not a bare minimum. In order to make sure that you have the correct answer to the nutrition riddle: “How much protein is enough?” your safest bet is to eat more than enough. Some menus will be provided in later publications. Getting “more than enough” protein is the only way I know of to make absolutely certain that you have bolted the door against premature aging of your precious body.