Asparagine
Asparagine is a nonessential amino acid, which means it is not required in the diet, but is manufactured from other amino acids in the liver. It is required for the production of proteins concerned with development of nerves, and the transmission of impulses across nerve endings. In other words, asparagine is involved in the metabolic control of cell functions in nerve and brain tissue. In the central nervous system, asparagine is needed to maintain a balance between being excessively nervous or overly calm. Asparagine can also convert one amino acid into another when the need arises. It also plays an important role in the synthesis and excretion of urea, which is the major waste product of excess dietary protein. Asparagine is most commonly found in whole grains, legumes, whey, soy, poultry, dairy, eggs, fish, meat, nuts, seeds, seafood, and beef. (For more detailed information, please visit ISM’s searchable database: Nutraceutical Search.)
A possible requirement for dietary asparagine during lactation was investigated by measuring any adverse effect of maternal asparagine deprivation on the body growth and brain development of nursing rat pups. Each dam was given 7 pups to nurse. Three groups of 5 dams each were deprived from the 1st (T1), 8th (T2), or 15th (T3) day of lactation until weaning (day 22); at weaning, the pups of each group weighed approximately 10% less than those of asparagine-fed controls. Brain development was also affected……… Thus, the development of neonatal rat brain is sensitive to even mild or transient forms of malnutrition, and a requirement for dietary asparagine during lactation seems evident.
o Newburg, DS, & Fillios, LC. (1982). Brain development in neonatal rats nursing asparagine-deprived dams. Dev Neurosci, 5(4), 332-44.
The effect of dietary asparagine on rat growth was investigated. Diets were formulated with L-amino acids so as to contain asparagine, aspartic acid, glutamine and/or glutamic acid in all possible combinations and then fed to weanling rats for 3 weeks. Of the four, only asparagine was found to be essential for optimal growth, and it was essential regardless of the presence or absence of any dietary combination of these related amino acids……….asparagine may be rate limiting to protein synthesis………as well as during dietary asparagine deprivation, which also decreased intracellular levels of unbound asparagine and led to irreversible deficits in development.
o Newburg, DS, Frankel, DL, & Fillios, LC. (1975). An Asparagine requirement in young rats fed the dietary combinations of aspartic acid, glutamine, and glutamic acid. J Nutr, 105(3), 356.
Asparagine has been reported to be a dietary requirement for optimal growth of the weanling rat; in the present study the possibility of a requirement for dietary asparagine during pregnancy was explored. Two distinct amino acid diets containing asparagine were selected, and each was compared with an identical diet lacking asparagines………. These data support the hypothesis that the greatest metabolic aberration immediately follows the onset of asparagine deprivation and, when this onset of deprivation occurs during the period of greatest fetal demand (the third trimester of gestation) the most severe consequences of insufficient asparagine result. Thus a requirement for asparagine during pregnancy is indicated, and its omission from the diet during periods of rapid fetal brain growth may impair neurological development in the fetus.
o Newburg, DS, & Fillios, LC. (1979). A Requirement for dietary asparagine in pregnant rats. J Nutr, 109(12), 2190.