Plasma amino acid concentrations in normal adults ingesting aspartame and monosodium L-glutamate as part of a soup/beverage meal.
We tested the hypothesis that ingestion of monosodium L-glutamate with aspartame produces a marked increase in plasma glutamate and aspartate concentrations. Twelve normal adults (6 males, 6 females) ingested three different soup/beverage meals in a balanced Latin square design. One meal (A) provided no aspartame (APM) or monosodium L-glutamate (MSG); a second (B) provided 50 mg MSG/kg body weight; while the third (C) provided 50 mg MSG and 34 mg APM per kg body weight. Plasma glutamate (Glu) concentrations were not significantly affected by meal A but increased significantly after meals B and C (no significant difference between B and C). Plasma aspartate (Asp) concentrations were not significantly affected by meal A but increased significantly after meals B and C (values significantly higher after meal C than meal B). Plasma Glu + Asp concentrations were not significantly affected by meal A but increased significantly from a mean (+/- SD) baseline value of 5.64 +/- 2.62 mumol/dL to high mean values of 23.1 +/- 7.29 and 26.8 +/- 9.74 mumol/dL after ingestion of meals B and C, respectively (no significant difference between meals B and C). Similarly, the area under the plasma Glu + Asp concentration-time curve did not differ significantly between meals B and C (624 +/- 197 v 763 +/- 277 mumol/dL x min, respectively). Peak plasma Glu + Asp concentrations for each subject (ignoring time) were also examined. The mean peak plasma Glu + Asp concentrations were 7.39 +/- 2.77, 23.0 +/- 6.61, and 27.3 +/- 9.07 mumol/dL, respectively after meals A, B, and C.
Stegink
L D
LD
Department of Pediatrics, University of Iowa College of Medicine, Iowa City 52242.
Filer
L J
LJ
Baker
G L
GL
D000328:Adult; D000596:Amino Acids / Q000097:blood*; D001218:Aspartame / Q000494:pharmacology*; D001224:Aspartic Acid / Q000097:blood; D004151:Dipeptides / Q000494:pharmacology*; D004435:Eating; D005260:Female; D005971:Glutamates / Q000097:blood / Q000494:pharmacology*; D006801:Humans; D007700:Kinetics; D008297:Male; D012016:Reference Values; D012970:Sodium Glutamate / Q000494:pharmacology*; D013997:Time Factors
D000596:Amino Acids; D004151:Dipeptides; D005971:Glutamates; D001224:Aspartic Acid; D012970:Sodium Glutamate; D001218:Aspartame