Amazing Power of Amino Acids

*Histidine is required for infants but its essentiality for adults has not been clearly established. It will be seen from this statement that nine amino acids are essential for maintenance of nitrogen equilibrium in human bodies. The estimated requirements of essential amino acids for infants, children and adults are given in Table B.

Men in the older age group appear to differ in their requirements. Studies seem to suggest an increase need for methionine and lysine for them. Infants and children have proportionally greater demands for essential amino acids than adults. In addition, infants require histidine as an essential amino acid.

* From Food and Nutrition Board, National Research Council : Improvement of Protein Nutrient. Washington, D.C. , National Academy of Sciences, 1973.
** 2 g. per kg. of body weight per day of protein of the quality listed in column 4 would meet the amino acids needs of the infant.

Factors in addition to the age, sex and physiological condition of an individual influence the requirements for specific amino acids. If total protein intake is low, small surpluses of certain amino acids can increase the need for others. The non-essential amino acids in protein also affect the quality of protein. For example, the amount of sulphur - containing essential amino acid methionine required may be somewhat reduced if cystine, a sulphur-containing non- essential amino acid,is supplied in the diet. Likewise, the presence in the diet of tyrosine, a non-essential amino acid similar in structure to phenylalanine, may reduce the requirement for phenylalanine.

Much research has been done on amino acids in recent times and this has paved the way for dramatic treatment and cure of different problems by their judicious use. They are now dubbed as " the nutrients of the 80’s" and "medical foods".