From the NYTimes:
Virtually all studies since then confirm that monosodium glutamate in normal concentrations has no effect on the overwhelming majority of peopleWikipedia seems to partially confirm this.
- The 1987 Joint Expert Committee on Food Additives of the United Nations Food and Agriculture Organization and the World Health Organization placed monosodium glutamate in the safest category of food ingredients.
- A 1991 report by the European Community's (EC) Scientific Committee for Foods reaffirmed monosodium glutamate's safety and classified its "acceptable daily intake" as "not specified", the most favourable designation for a food ingredient. In addition, the EC Committee said, "Infants, including prematures, have been shown to metabolize glutamate as efficiently as adults and therefore do not display any special susceptibility to elevated oral intakes of glutamate."
- A 1992 report from the Council on Scientific Affairs of the American Medical Association stated that glutamate in any form has not been shown to be a "significant health hazard".
- A 1995 FDA-commissioned report acknowledged that "An unknown percentage of the population may react to monosodium glutamate and develop monosodium glutamate symptom complex, a condition characterized by one or more of the following symptoms:
- Burning sensation in the back of the neck, forearms and chest
- Numbness in the back of the neck, radiating to the arms and back
- Tingling, warmth and weakness in the face, temples, upper back, neck and arms
- Facial pressure or tightness
- Chest pain
- Rapid heartbeat
- Bronchospasm (difficulty breathing)
- Sweating." This list of mostly very non-specific and common symptoms was compiled from anecdotal reports
- A 2002 report from researchers at Hirosaki University in Japan found rats fed on diets very high in glutamate (up to 20%) suffered eye damage. Lead researcher Hiroshi Ohguro said the findings might explain why, in eastern Asia, there is a high rate of normal-tension glaucoma.