Plasma glutamate concentrations in adult subjects ingesting monosodium L-glutamate in consomme

The effect of MSG ingestion in consomme on the plasma glutamate concentration response was studied in normal adult subjects. In the first study nine subjects ingested three different consomme servings (providing 0, 25 and 50 mg/kg body weight MSG) in a Latin square design. Plasma glutamate concentrations were not significantly increased over baseline (3.69 +/- 1.08 mumol/dl) when no added MSG was present. However, mean peak plasma glutamate levels increased proportional to dose when MSG was added (10.2 +/- 2.00 and 17.0 +/- 8.06 mumol/dl at 25 and 50 mg/kg body weight respectively). Since six of the nine subjects in this study reported an idiosyncratic symptom response when tested with MSG at 150 mg/kg body weight, nine additional subjects were also studied. They ingested consomme providing MSG at 0 and 50 mg/kg body weight. No significant differences in plasma amino acid responses were noted between the two groups of subjects.