Effect of sucrose ingestion on plasma glutamate concentrations in humans administered monosodium L-glutamate

Abstract

Plasma glutamate concentrations in human subjects are markedly lower when monosodium L-glutamate (MSG) is ingested in consomme with starch than when ingested in consomme alone. This study investigated whether sucrose had a similar effect. Six normal adult subjects (three male, three female) ingested two servings of beef consomme each providing 50 mg MSG/kg body weight in a randomized crossover design. One serving of consomme contained no added carbohydrate; the other provided 0.5 g sucrose/kg body weight. Ingestion of the consomme without sucrose significantly (p < 0.05) increased the mean plasma glutamate concentration from baseline (4.44 ± 0.97 μmol/dl) to a peak value of 18.1 ± 6.99 μmol/dl 30 min after dosing. The area under the plasma glutamate concentration-time curve was 553 ± 238 μmol/dl x min. When the consomme contained 0.5 g sucrose/kg body weight, both the mean peak plasma glutamate concentration (5.48 ± 2.19 μmol/dl) and the area under the curve (105 ± 46 μmol/dl x min) were significantly lower. These data confirm that metabolizable carbohydrate has a significant effect on plasma glutamate concentration response after MSG loading.