Admissible daily intake for glutamate

Area of Science:

• Nutrition Science
• Food Safety
• Toxicology

Background:

• Dietary glutamate (Glu) intake comprises protein-bound and free forms, with the latter found in foods and additives.
• Enterocytes actively metabolize ingested Glu, limiting its systemic availability.
• Assessing the risks of free Glu salts requires human studies, supplemented by animal models when human data are absent.

Purpose of the Study:

• To review the admissible intake of free glutamate (Glu) additives.
• To evaluate the systemic availability and potential risks of dietary free Glu salts.
• To determine the acceptable daily intake (ADI) for free Glu salts based on scientific evidence.

Main Methods:

• Analysis of human studies on the transfer of dietary free Glu salts into the bloodstream.
• Utilization of experimental animal models to assess potential risks when human data are unavailable.
• Application of No Observable Adverse Effect Level (NOAEL) and uncertainty factors to derive ADI values.

Main Results:

• A NOAEL of 3200 mg/kg/day in rodents with a 100-fold uncertainty factor yields an ADI of 30 mg/kg/day for free Glu salts.
• A higher NOAEL (>6000 mg/kg/day) with a 25-fold uncertainty factor results in an ADI of 240 mg/kg/day for free Glu salts.
• Current discussions suggest an ADI range of 30–240 mg/kg/day for free Glu salts.

Conclusions:

• The acceptable daily intake (ADI) for free glutamate (Glu) salts varies significantly based on the chosen animal model NOAEL and uncertainty factors.
• The range of 30–240 mg/kg/day reflects the current scientific discourse on safe consumption levels of free Glu additives.
• Further research and consensus on safety factors are needed for precise ADI determination.