Reconsidering the effects of monosodium glutamate: a literature review.
OBJECTIVE
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."


METHODS
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.


CONCLUSIONS
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.
Freeman
Matthew
M
OhioHealth, Columbus, Ohio, USA. freeman.224@osu.edu
D001249:Asthma / Q000139:chemically induced; D019317:Evidence-Based Medicine; D005503:Food Additives / Q000009:adverse effects*; D006261:Headache / Q000139:chemically induced; D006801:Humans; D008881:Migraine Disorders / Q000139:chemically induced; D009722:Nurse Practitioners / Q000458:organization & administration; D024802:Nurse's Role; D052756:Nutritional Sciences / Q000193:education; D010353:Patient Education as Topic; D012107:Research Design / Q000592:standards; D012147:Restaurants; D012307:Risk Factors; D012970:Sodium Glutamate / Q000009:adverse effects*; D013577:Syndrome; D014987:Xerostomia / Q000139:chemically induced
D005503:Food Additives; D012970:Sodium Glutamate