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Plasma glutamate concentrations in 1-year-old infants and adults ingesting monosodium L-glutamate in consommé
Insights
Infants and adults show similar plasma glutamate responses after ingesting monosodium L-glutamate (MSG). This study found no significant difference in how quickly 1-year-olds metabolize MSG compared to adults.
Area of Science:
- Biochemistry
- Pediatric Nutrition
- Metabolism Studies
Background:
- Infant metabolism and nutrient processing differ from adults.
- Previous assumptions suggested slower glutamate metabolism in infants.
- Understanding monosodium L-glutamate (MSG) processing is crucial for infant dietary safety.
Purpose of the Study:
- To investigate and compare the plasma glutamate and aspartate concentrations in 1-year-old infants and adults.
- To test the hypothesis that infants metabolize glutamate more slowly than adults.
- To determine the metabolic response to varying doses of MSG in young children.
Main Methods:
- Eight 1-year-old infants and nine adults ingested beef consommé with MSG at 0, 25, and 50 mg/kg body weight.
- Plasma glutamate and aspartate levels were measured sequentially over 2 hours post-ingestion.
- Data from infants were compared with those from adult subjects.
Main Results:
- Peak plasma glutamate concentrations and area under the curve values in infants were comparable to adults across all tested MSG doses.
- Adult peak plasma glutamate concentrations ranged from 5.59 to 17.0 mumol/dl.
- Infant peak plasma glutamate concentrations ranged from 6.94 to 12.0 mumol/dl, with similar area under the curve values to adults.
Conclusions:
- The plasma glutamate concentration response in 1-year-old infants is not significantly different from that observed in adults.
- Infants appear to metabolize ingested monosodium L-glutamate at a rate comparable to adults.
- These findings challenge the hypothesis of slower glutamate metabolism in infants.
Abstract:
This study tested the hypothesis that infants metabolize glutamate more slowly than adults. Eight 1-yr-old infants ingested 160 ml of a beef consommé providing monosodium L-glutamate at 0, 25, and 50 mg/kg body weight. Plasma glutamate and aspartate concentrations were measured sequentially for the next 2 h. The results were compared to values noted in nine adult subjects ingesting equivalent doses of monosodium L-glutamate in consommé. In adults, mean (+/- SD) peak plasma glutamate concentrations were 5.59 +/- 1.56, 10.2 +/- 2.08, and 17.0 +/- 8.06 mumol/dl, respectively; the area under the plasma glutamate concentration time curves were 96 +/- 42, 257 +/- 80, and 442 +/- 303 mumol/dl X min, respectively. In infants, the mean (+/- SD) peak plasma glutamate concentrations were 6.94 +/- 1.43, 10.6 +/- 2.36, and 12.0 +/- 1.16 mumol/dl, respectively; the plasma glutamate area under the curve values were 47 +/- 28, 191 +/- 85, and 358 +/- 105 mumol/dl X min, respectively. The data indicate that the plasma glutamate concentration response in 1-yr-old infants ingesting MSG at these glutamate doses is no higher than values observed in adult subjects.