Aspartic Acid

Description

Aspartic acid is a nonessential amino acid, which means it is manufactured from other amino acids in the liver; it does not have to be obtained directly through the diet.

Aspartic acid is very important in the urea cycle for the proper elimination of waste products from dietary protein. Poor control of the urea cycle may be related to symptoms such as chronic headache, fatigue, irritability, lack of concentration, mental confusion, and intolerances to various foods, particularly high-protein foods.

Deficiencies of nonessential amino acid will not occur if a well-balanced diet is consumed because the intake of proper foods will allow the body to produce exactly the amount of amino acid required to function optimally.

Aspartic acid has been used as mineral salts such as magnesium aspartate or potassium aspartate to help improve energy production in exercising muscles.

Recommended Dietary Allowances

An RDA has not been established for aspartic acid because it is a nonessential amino acid.

Food Sources

Aspartic acid is a nonessential amino acid, which means it is manufactured from other amino acids in the liver; it does not have to be obtained directly through the diet.

Method of Action

Aspartate and glutamate participate within the neurotransmitter family of substances. This family also includes acetylcholine, noradrenaline, and gamma-amino butyric acid (GABA). Glutamate is one of the most important excitatory transmitters in the central nervous system in lower animals and may also be important in humans.

Aspartate has been considered to be a neurotransmitter, whereas GABA and glycine are thought to be major inhibitory transmitters. Excitatory transmitters such as aspartate lead to depolarization of the nerves; on the other hand, inhibitory transmitters cause hyperpolarization, apparently by increasing the permeability within the nerve of potassium and chloride.

Glutamate and aspartate are also very important in the tricarboxylic acid cycle (Kreb's cycle), from which most of the energy is produced by metabolism. Their reaction in this pathway is by what is called malate-aspartate shuttle for the transportation of energy into the mitochondria. Recent studies in trained athletes indicate some advantage of using magnesium or potassium aspartate as mineral sources for improving aerobic competency during exercise. Minerals form a unique chelate with aspartic acid to form aspartates. Potassium and magnesium forms of the aspartates appear to be agents which enhance muscular work and aerobic competency. Doses of these mineral salts range between 500 and 2000 mg per day.

Abstracts

References

Blackburn, G.L., Grant, J.P., Young, V.R., ed. Amino Acids Metabolism and Medical Applications.

Lund, P. Precursors of Urea. Nitrogen Metabolism in Man, eds. J.C. Waterlow and J.M.L. Stephen. London: App Sci Publi, 1981.

Munro, H.N. & Crim, M.C. The Proteins and Amino Acids. Modern Nutrition in Health and Disease, eds. R.S. Goodhart & M.E. Shils, 6 ed. Phila. Lea and Febiger, 1980.

Stewart, P.M., Batshaw, M., Valle, D., & Walser, M. Effects of Arginine-Free Meals on Ureagenesis in Cats. American Journal of Physiology, 241:E310-E315, 1981.

Vilstrup, H. Synthesis of Urea after Stimulation with Amino Acids: Relation to Liver Function. Gut, 21:990-5, 1980.

Young, V.R., Meguid, M., Meredith, D.E., & Bier, D.M. Recent Developments in Knowledge of Human Amino Acid Requirements. Nitrogen Metabolism in Man, eds. J.C. Waterlow & J.M.L. Stephen. London. Applied Science Publishers, 1981.