seems that i found some answers myself.
Max intake seems to be 120MG/KG
OhioHealth, Columbus, Ohio, USA. freeman.224@osu.edu
PURPOSE: This article reviews the literature from the past 40 years of research related to monosodium glutamate (MSG) and its ability to trigger a migraine headache, induce an asthma exacerbation, or evoke a constellation of symptoms described as the "Chinese restaurant syndrome." DATA SOURCES: Literature retrieved by a search using PubMed, Medline, Lexis-Nexus, and Infotrac to review articles from the past 40 years.
CONCLUSIONS: MSG has a widespread reputation for eliciting a variety of symptoms, ranging from headache to dry mouth to flushing. Since the first report of the so-called Chinese restaurant syndrome 40 years ago, clinical trials have failed to identify a consistent relationship between the consumption of MSG and the constellation of symptoms that comprise the syndrome. Furthermore, MSG has been described as a trigger for asthma and migraine headache exacerbations, but there are no consistent data to support this relationship. Although there have been reports of an MSG-sensitive subset of the population, this has not been demonstrated in placebo-controlled trials. IMPLICATIONS FOR PRACTICE: Despite a widespread belief that MSG can elicit a headache, among other symptoms, there are no consistent clinical data to support this claim. Findings from the literature indicate that there is no consistent evidence to suggest that individuals may be uniquely sensitive to MSG. Nurse practitioners should therefore concentrate their efforts on advising patients of the nutritional pitfalls of some Chinese restaurant meals and to seek more consistently documented etiologies for symptoms such as headache, xerostomia, or flushing.
PMID: 16999713 [PubMed - indexed for MEDLINE]
Beyreuther K, Biesalski HK, Fernstrom JD, Grimm P, Hammes WP, Heinemann U, Kempski O, Stehle P, Steinhart H, Walker R.
ZMBH, University of Heidelberg, Germany.
OBJECTIVE: Update of the Hohenheim consensus on monosodium glutamate from 1997: Summary and evaluation of recent knowledge with respect to physiology and safety of monosodium glutamate. DESIGN: Experts from a range of relevant disciplines received and considered a series of questions related to aspects of the topic. SETTING: University of Hohenheim, Stuttgart, Germany. METHOD: The experts met and discussed the questions and arrived at a consensus. CONCLUSION:
Total intake of glutamate from food in European countries is generally stable and ranged from 5 to 12 g/day (free: ca. 1 g, protein-bound: ca. 10 g, added as flavor: ca. 0.4 g). L-Glutamate (GLU) from all sources is mainly used as energy fuel in enterocytes. A maximum intake of 6.000 [corrected] mg/kg body weight is regarded as safe. The general use of glutamate salts (monosodium-L-glutamate and others) as food additive can, thus, be regarded as harmless for the whole population. Even in unphysiologically high doses GLU will not trespass into fetal circulation. Further research work should, however, be done concerning the effects of high doses of a bolus supply at presence of an impaired blood brain barrier function. In situations with decreased appetite (e.g., elderly persons) palatability can be improved by low dose use of monosodium-L-glutamate.Stevenson DD.
Division of Allergy, Asthma and Immunology, Scripps Clinic and the Scripps Research Institute, La Jolla, CA 92037, USA.
Allen et al. (1987) conducted oral monosodium glutamate (MSG) challenges with 32 asthmatic volunteers and reported that 14 reacted to MSG. Another study by Moneret-Vautrin (1987) also reported MSG-induced asthma attacks in 2 of 30 asthmatic patients. Four additional studies have been conducted and none has confirmed the results of the above authors. These studies, by Schwartzstein et al. (1987), Germano (1991), Woods et al. (1998) and Woessner et al. (1999), challenged a total of 45 patients who gave a history of asthma attacks in oriental restaurants. None of these patients experienced asthmatic reactions after ingesting MSG (one-sided confidence interval of 0-0.066). Another 109 asthmatic patients, without a history of asthma in oriental restaurants, also did not react to ingestion of MSG (one-sided confidence interval of 0-0.027). With a confidence interval < 0.05 there is a >95% probability that MSG history-negative asthmatic patients are not sensitive to MSG. For the MSG history-positive asthmatics, 45 patients, in well-performed studies, underwent negative challenges to MSG, contrasting with two studies reporting positive challenges. Allen et al. (1987) and Moneret-Vautrin (1987), who reported positive MSG challenge results, performed studies with the following characteristics: 1) single blinded, conducted after discontinuing essential antiasthma medications; 2) used effort-dependent peak expiratory flow rate measurement of lung function; 3) added AM bronchodilators in some patients; 4) ignored wandering baselines on the placebo challenge days; and 5) conducted some challenges in the AM and some at night.
In summary, the existence of MSG-induced asthma, even in history-positive patients, has not been established conclusively.Walker R, Lupien JR.
School of Biological Sciences, University of Surrey, Guildford GU2 5XH, Surrey, UK and. Food and Nutrition Division, FAO, 00100 Roma, Italy.
L-Glutamic acid and its ammonium, calcium, monosodium and potassium salts were evaluated by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) in 1988. The Committee noted that intestinal and hepatic metabolism results in elevation of levels in systemic circulation only after extremely high doses given by gavage (>30mg/kg body weight). Ingestion of monosodium glutamate (MSG) was not associated with elevated levels in maternal milk, and glutamate did not readily pass the placental barrier. Human infants metabolized glutamate similarly to adults. Conventional toxicity studies using dietary administration of MSG in several species did not reveal any specific toxic or carcinogenic effects nor were there any adverse outcomes in reproduction and teratology studies. Attention was paid to central nervous system lesions produced in several species after parenteral administration of MSG or as a consequence of very high doses by gavage. Comparative studies indicated that the neonatal mouse was most sensitive to neuronal injury; older animals and other species (including primates) were less so. Blood levels of glutamate associated with lesions of the hypothalamus in the neonatal mouse were not approached in humans even after bolus doses of 10 g MSG in drinking water. Because human studies failed to confirm an involvement of MSG in "Chinese Restaurant Syndrome" or other idiosyncratic intolerance, the JECFA allocated an "acceptable daily intake (ADI) not specified" to glutamic acid and its salts. No additional risk to infants was indicated. The Scientific Committee for Food (SCF) of the European Commission reached a similar evaluation in 1991. The conclusions of a subsequent review by the Federation of American Societies for Experimental Biology (FASEB) and the Federal Drug Administration (FDA) did not discount the existence of a sensitive subpopulation but otherwise concurred with the safety evaluation of JECFA and the SCF.
The weight of the evidence supports the designation of MSG as a generally safe food flavoring agent. Neither epidemiologic surveys nor challenge studies provide evidence that ingestion of MSG is associated with adverse reactions in the population at large. In subjects who report adverse reactions to MSG, rigorous DBPC challenge studies indicate that large doses of MSG given without food may elicit more symptoms than a placebo in individuals who believe that they react adversely to MSG. However, neither persistent nor serious effects from MSG ingestion were observed, and the frequency of the responses was low. More importantly, the responses reported were inconsistent and were not reproducible. The responses were not observed when MSG was given with food.
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