In my last post “Proteins the Building Blocks” the protein dynamics (role and sources) were elaborated. In this post we will go further and find out how we can maintain vigor and youth by adequate consumption of quality proteins.
In the digestive system, the ingested proteins are broken down into amino acids, and absorbed into blood circulation. Tissues take these amino acids as per their requirement for repair or synthesis. Surplus amino acids go to the liver and stored in a common pool. If two or more incomplete proteins are eaten at the same meal, one protein may supply EAA lacking in the other. For example cereals lack lysine, tryptophan & threonine;. Pulses (methionine and cysteine);. Vegetables, nuts, and seeds (methionine, threonine, lysine) and sea weed (histidine, lysine). If cereals and pulses are taken together, they act like complete proteins and supply all EAA. Dr Paul R Cannon (1954) showed, that if half of EAA are eaten in one time, and other half is eaten later, the body does not form proteins from them. The standards of liver are pretty high and only complete proteins are held in storage. Surplus amino acids are diverted to form glucose or fat. Nowadays, high protein diets are being given for weight reduction, but if quality of proteins is not good, it will be used for fat or glucose synthesis leading to weight gain instead of weight loss. When all EAA are supplied in small quantities, or not supplied at all, the cell will form less proteins, affecting the overall function of the organ or tissue. Consistent deficiency over long periods will eventually lead to reduction in strength and functions of concerned organ. It is observed that people suffering from metabolic syndrome are deficient in amino acids like tryptophan (essential for making serotonin) and methionine (essential for making glutathione, the liver antioxidant). To avoid wastage of proteins, it is imperative that all our meals must supply all EAA.
Processing alters the protein content of foods drastically. Whole wheat is good source of protein. However, when it is converted to fine flour or white flour (maida), it looses all its fiber, micronutrients and proteins ; and left only with starch. During refining of flour, 70-80% of vitamin B complex and mineral content is lost. Fine milling of rice also removes fiber and essential nutrients. Eating such wheat or rice amounts to eating sugar only. Some doctors advise consumption of egg white only, but removal of egg yolk leads to removal or reduction of some EAA, rendering it an incomplete protein source. Companies tout proteins as weight loss magic and large number of people use protein powders, shakes, bars, protein coffee, cookie etc for weight loss or muscle gain. It must be understood that most of these supplements are very high in branched chain amino acids (BCAA); leucine, isoleucine and valine. Only those people, who do lots of body building, require BCAA. For rest of us it’s a wastage. The surplus EAA will be diverted to form glucose or fat. Meat is supposed to be rich source of all EAA. But not all meats are equal. It applies only to the meat of animals reared in natural environment. Processed meat (bacon, sausage, salami etc) has been linked to all health problems due to excess iron (oxidative stress), BCAAs, high nitrates (a known factor for colon cancer) and other additives. Hence consumption of real foods with protein is recommended. Processed proteins are bad for health.
If protein intake is adequate, we can maintain youthful looks till late life. Gradual decline of 30-50% occurs in the muscle mass between 40 and 80 years of age. The recommended daily allowance (RDA) for protein is 0.8-1 gm/kg body weight. Studies indicate that this level of protein intake fails to prevent muscle loss with age. For older individuals the RDA should be 1-1.2 gm/kg body weight. For acute and chronic illnesses, it should be 1.2-1.5 gm/kg/day and during severe illness, injuries or malnutrition, it should be increased to 2 gm/kg. It is estimated that consumption of 25-30 gm of proteins per meal is optimal for synthesis of muscle mass. Some people fear that high protein consumption will lead to kidney overload. However, a review by Willaim F Martin found no detrimental effects on kidney, with the high protein diets in healthy individuals.
Today the greatest hinderance to human health is ignorance. It is observed that 60% of population gets far less protein than required. Since the complete proteins most enjoyed are far expensive, persons with low income invariably suffer form protein deficiency. Yet with the knowledge, adequate proteins can be obtained with limited budget also. Unfortunately such skills are never taught in schools. The knowledge has been greatly distorted by industry to suit their interest. Poshanshiksha.com is dedicated to spread nutrition awareness as a whole. National Institute of Nutrition (Hyderabad, India) has done a yeoman job by publishing a book “Nutritive value of Indian Foods” which gives a detailed account of macro and micro nutrients content of Indian foods. One can consult this book for further information.
We have learnt an important lesson from the above discussion that for optimum body functions and vitality, all the meals should provide all EAA in appropriate quantities.
To conclude, it can be stated that proteins are most important food component. Our food must be able to provide around 25-30 gms of proteins per meal, to maintain health, vitality and youth.
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