(This article deals with basic concepts, and the role played by protein in health)

Role of Proteins in Our Life

Proteins are the stuff we are made up of. Skin, muscles, internal organs, nails, hair, brain and base of bones, all have proteins as main constituent of cells. Only when proteins of excellent quality and quantity are supplied through diet, our organs can function and repair themself properly. 

Two classical diseases of severe protein deficiency are described; Marasmus, (caused by lack of proteins and calories) and Kwashiorkor (caused by lack of protein but not calorie). These diseases are not normally seen now. However, sub optimal deficiency of proteins is wide spread and can give rise to array of problems generally not recognized by doctors, but can be treated simply by diet therapy. In subsequent paras, effects of proteins in our life is discussed. 

Posture; an estimate of the protein status. Since proteins form a major portion of the muscle mass, a glance at the posture will give a rough estimate of protein status of the body. When muscles are well nourished, they automatically hold the body erect. When they do not receive the food they require, they lose their elasticity and posture becomes poor. A mother, scolding her child to sit straight, is in fact complaining of her own failure to give proper nutrition.  Adelle Davis in her book “Lets eat right and stay fit” describes the drastic improvement in posture of a sixty eight year old woman, when a protein rich diet was given to her. Another case described is a case of three year old child, who went a complete transformation of his posture after diet therapy. The child reported to her with pot belly, sunken chest and flat feet, but after three months of protein therapy, developed high chest, arched feet and total absence of pot belly. 

Hair and nails are also made up of proteins. Nails break, peel or crack can be improved by protein therapy. Hair also loose elasticity and break with protein deficient diet. People take costly collagen supplements for skin care and anti wrinkle effects, but these can be prevented by taking a diet rich in proteins at much lesser cost.

High Resistance to Diseases. If protein intake is adequate, a high resistance to diseases can be expected. Antibodies are made up of proteins. If supply is good, the quality of antibodies will also be excellent. Phagocytes (cells eating foreign bodies) are chiefly made up of proteins and can be produced in adequate amounts if dietary intake of protein is sufficient. 

Digestion. Adequate protein is also necessary for health of digestive system. Enzymes are made of protein. Stomach and intestines can make adequate enzymes only if protein supply is adequate. For proper peristalsis (contraction and relaxing movement of stomach and intestines to push food), the wall of stomach and intestines should be strong. Inadequate protein will result in weak musculature and weak movements. It may alter the internal posture of alimentary tract. The stomach may sag, the intestines may coil on pelvic bones. The flabby muscles of intestines can no longer contract normally and food remains in digestive tract for longer time. In the large intestine, billions of bacteria will produce putrefying gases (carbon dioxide, methane, hydrogen sulphide etc) and flatulence results. Constipation may occur due to failure of flabby muscles of intestines to push out waste efficiently. To treat constipation, the patients resort to laxatives, whereas the real malady is protein intake. 

Waste disposal. Albumin (a protein) binds with large number of compounds in blood and facilitates transport of waste materials to kidney. If albumin is suboptimal in quality and quantity, it will hamper proper transport of waste.

Hormones are made of proteins. We know that hormones control various body functions. Proteins are also essential for blood clotting. 

Chronic fatigue. There are multiple reasons of fatigue, anemia being number one. Anemia is reduction in hemoglobin concentration in blood. Deficiency of proteins may reduce the globulin part and result in anemia in spite of adequate iron in blood.

Quality of Proteins Defined

Proteins are made up of chains of amino acids called peptide chains. Proteins can be complete proteins or incomplete proteins based on presence of essential amino acids (EAA). There are twenty two amino acids required by human body for making proteins of different types. All amino acids, barring ten amino acids (called essential amino acids), can be synthesized by the liver. These ten essential amino acids (EAA); alanine, histidine, tyrosine, tryptophan, phenylalanine, lysine, leucine, isoleucine, methionine and valine are required to be provided by food. A protein which can supply all EAA is called as good quality protein or complete protein and proteins which supplies few or nil EAA are poor quality proteins or incomplete proteins. 

Sources

Animal sources. Milk and milk products, meat, fish, eggs liver and kidneys are rich sources of proteins with highest protein value. Protein from muscle meat are complete but contain fewer amino acids then glandular meat and therefore less valuable. Animals know better than us. A lion after killing its prey does not eat muscles, but its organ. On the whole animal proteins contain more EAA than vegetable proteins. Egg white and gelatin lack essential amino acids and are poor sources. Unfortunately doctors have been preaching to take egg white only for the fear of cholesterol. Whole egg must be consumed not the egg white.

Plant sources. Now a days there is lot of stress on vegetarianism. It is believed that plant proteins are cardio-protective and more healthy, but in reality, most of the plant proteins lack one or another essential amino acids (EAA) and therefore are incomplete proteins. Cereals and millets (our staple diet) lack lysine. Pulses lack methionine. Eating a combination of two may supplement each other, improving quality of proteins consumed. Combination of pulses and cereals will be better than consuming them alone. Soyabean, brewers yeast, nuts, cotton seeds, quinoa, amaranthus, buckwheat, spirulina, hemp seeds, chia seeds and germ of cereals are plant sources of complete proteins. For vegetarians, knowledge of good protein sources is a must. Its challenging to get adequate proteins in diet for vegans.

Requirement. As per WHO, the recommended allowance of protein is 1 gm per kg body weight. Children require higher amounts which may vary from 1.2-1.5 gms per kg body weight. 

This is part I of the article on proteins dealing with basic concepts of protein. In next post the digestion of proteins and its utilization by body will be discussed.

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