In Chapter 3, Proteins, I discussed each amino acid and its application to nutritional medicine. Please refer to that section for current information on amino acid functions, metabolism, and therapy. However, the research and new findings in regard to amino acid use in medicine are moving very rapidly, so we might watch the medical literature and news for future applications.

The most common amino acids used in treating health conditions have been tryptophan, lysine, and phenylalanine. On the upswing are cysteine, carnitine, arginine, and tyrosine. All of these, except phenylalanine, are used in their L- form. (Both D- and DL-phenylalanine also have uses.) Each of the other individual amino acids have some possible uses as well. Their therapeutic amounts may range from 250 mg. to 5–10 grams daily.

I suggest that single L- amino acids not be used with regularity, as this may affect the balance and functions of the others. (This is also true when taking higher amounts of single B vitamins or minerals as well.) I would suggest two weeks as the limit for taking any single nutrient to the exclusion of the others of its family. After that time, either it should be stopped, or the other amino acids or B vitamins, as the case may be, should be taken at the same time.

Deoxyribonucleic and Ribonucleic Acids (DNA and RNA)
These nucleic acid polymers act as the genetic code and translators for the proteins, which in turn are the molecular building blocks of body tissues, and actually stipulate which amino acids go together to form body proteins. DNA is found mainly in the nuclei of cells and carries the genetic message; small amounts of DNA are also found in the mitochondria. RNA helps transfer this genetic message to guide the manufacture of proteins that use all the amino acids either created by the body or extracted from foods.

There are supplements containing good levels of nucleic acids, most commonly yeast or organ meats such as calf thymus, which have been recommended to retard aging, improve memory, or improve the immune or other protein functions. However, there is no proof that RNA or DNA, when taken orally, performs any of these fabulous feats. Most of the oral nucleic acid supplement is broken down into purines and pyrimidines, the basic components of RNA and DNA. These purines, such as adenine and guanine, and pyrimidines, such as cytosine, uracil, and thymine, may have some cellular regeneration functions and thus could help slow aging, improve immune functions, and so on. As these components are absorbed, they may aid the production of the body’s RNA or DNA, though this has not been proved. Injectable nucleic acids may offer some benefit. These have been used to slow skin aging particularly.