Plasma, Erythrocyte and Human Milk Levels of Free Amino Acids in Lactating Women Administered Aspartame or Lactose

Abstract

Aspartame is a dipeptide (L-aspartyl-L-phenylalanyl methyl ester) with a sweetening potential of 180 to 200 times that of sucrose. Questions have been raised about the potential toxic effects of its constitu ent amino acids when the compound is ingested in large amounts by lactating women. Plasma, erythrocyte and milk levels of free amino acids were measured in six normal female subjects with established lactation after oral administration of either aspartame or lactose at 50 mg/kg body weight in a cross-over design. No significant change in plasma or erythrocyte aspartate levels was noted following aspartame or lactose administration. Plasma phenylalanine levels increased approximately fourfold over fasting values 45 minutes after aspartame loading (P < 0.001), and returned to baseline by 4 hours. Erythrocyte phenylalanine levels showed similar changes. No statistically significant difference in milk aspartate or phenyl alanine levels between aspartame and lactose loading were noted using the paired i-test. When milk data were subjected to curve analysis using orthogonal polynomials (mean, linear, cubic, quadratic), small, but statisti cally significant differences in overall milk aspartate (P â€"0.04, linear only) and phenylalanine (P = 0.034, mean only) levels were noted during the immediate 4 hour post-loading period. However, these small increases would not meaningfully affect aspartate or phenylalanine intake of an in fant.

Nonnutritive Sweeteners in Breast Milk

“…The absence of measurable aspartame was not surprising as aspartame is rapidly metabolized into aspartic acid and phenylalanine following ingestion. Changes in aspartate and phenylalanine concentrations following aspartame exposure were previously documented, yet not considered to be clinically relevant (Stegink et al, 1979). However, this assessment is controversial, since animal studies suggested adverse consequences on metabolic programing through exposure to aspartame during pregnancy (Araujo et al, 2014).…”

Dramatic increases in blood glutamate concentrations are closely related to traumatic brain injury-induced acute lung injury

“…Despite biological variations, blood glutamate concentrations are relatively stable under physiological conditions 16, 17 . However, in the present study, we found that the blood glutamate concentrations of patients with TBI or MPT were significantly higher than those in healthy volunteers and were related to injury severity in both patient groups, although the mechanisms involved may be different.…”

Use of Alternative Sweeteners in Diabetic Diet

“…Glutamate is in widespread use in food, particularly as monosodium glutamate (MSG). Toxicity has been demonstrated primarily in mice (72,73); in normal humans, controlled studies of aspartame alone and aspartame plus MSG ingestion at expected and abuse levels of consumption showed no effect of aspartame on plasma concentrations of aspartate and glutamate beyond those arising from MSG contained in the meals themselves (74)(75)(76)(77)(78). The FDA concluded there is no evidence that the ingestion of aspartame, either alone or together with glutamate, contributes to brain damage or dysfunction of neuroendocrine regulatory systems (71).…”

“…The question was raised initially as to whether aspartame use could raise plasma phenylalanine levels sufficiently to cause mental retardtion similar to that seen in PKU. Clinical studies demonstrated, however, that aspartame use could not be expected to increase the incidence of the form of mental retardation associated with sustained elevation of plasma phenylalanine levels (71,(74)(75)(76)(77)(80)(81)(82)(83). It was concluded that the marketing of aspartame would not create any additional risk to PKU children not on a restricted diet, individuals heterozygous for PKU, undetected cases of PKU, or pregnant women with the special condition hyperphenylalaninemia (71).…”