MSG

Dr Wilson, Is MSG bad for us and if so, why? Thank you.

Hello CH,
I do not know the answer to your question. The two most recent comprehensive reviews on the topic indicate that there are no statistically significant negative health effects from MSG consumption; the abstracts of these reviews are below. However, in my opinion, since glutamate is a neurotransmitter and some people may experience an impact and those expressing a concern over symptoms should be taken seriously regardless of what the science says is true for the general population (that there is no effect). Until we know more, a person should pay careful attention to how their body reacts to any food additive.

Reconsidering the effects of monosodium glutamate: a literature review, J Am Acad Nurse Pract. 2006 Oct;18(10):482-6. Freeman M. email freeman.224@osu.edu, OhioHealth, Columbus, Ohio, USA. 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.

Eur J Clin Nutr. 2007 Mar;61(3):304-13. Consensus meeting: monosodium glutamate - an update. 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.