最严格的一项是多中心试验：专门招来自认为对味精敏感的人，空腹一次给 5 g 的大剂量。空腹大剂量时，报告症状的人比吃安慰剂时多一些；但同一个人换一次重测往往对不上，和饭一起吃时也没有看到这种反应。美国 FDA 委托 FASEB 做的独立审查结论一致：在正常饮食的量下，味精对一般人群是安全的；只有空腹一次吃到 3 g 或更多时，少数人可能出现短暂、轻微的不适。
Kwok, R. H. M. (1968). Chinese-restaurant syndrome [Letter to the editor]. New England Journal of Medicine, 278(14), 796. The anecdotal letter that originated the 'MSG symptom complex' narrative. 10.1056/NEJM196804042781419
Yamaguchi, S., & Ninomiya, K. (2000). Umami and food palatability. Journal of Nutrition, 130(4S Suppl), 921S-926S. Reviews the independent umami taste pathway and glutamate's natural occurrence in foods. 10.1093/jn/130.4.921S
Raiten, D. J., Talbot, J. M., & Fisher, K. D. (Eds.). (1995). Analysis of adverse reactions to monosodium glutamate (MSG), report prepared by FASEB for the U.S. FDA. Journal of Nutrition, 125(11), 2891S-2906S. Concluded MSG is generally safe at normal dietary intake. PubMed indexes the executive summary (PMID 7472671) without an abstract and the report text could not be re-read (publisher page blocked, 2026-09-25); FDA's MSG Q&A (fda-msg-qa) summarises this report's finding of transient, mild symptoms in some sensitive people after 3 g or more without food. 10.1093/jn/125.11.2891S
Geha, R. S., Beiser, A., Ren, C., et al. (2000). Review of alleged reaction to monosodium glutamate and outcome of a multicenter double-blind placebo-controlled study. Journal of Nutrition, 130(4S Suppl), 1058S-1062S. Double-blind placebo-controlled challenges failed to reliably reproduce MSG symptoms at dietary doses. Note: the id says JACI but this record is the J Nutr summary (PMID 10736382); the full trial report is geha-2000-msg-multicenter-challenge. Summary abstract: a multicenter double-blind placebo-controlled challenge in 130 people who reported MSG reactions; large doses given without food may elicit more symptoms than placebo, but responses were infrequent, inconsistent and not reproducible, and were not seen when MSG was given with food (abstract, PMID 10736382). 10.1093/jn/130.4.1058S
Geha, R. S., Beiser, A., Ren, C., Patterson, R., Greenberger, P. A., Grammer, L. C., et al. (2000). Multicenter, double-blind, placebo-controlled, multiple-challenge evaluation of reported reactions to monosodium glutamate. Journal of Allergy and Clinical Immunology, 106(5), 973-980. 130 self-selected people who reported MSG reactions were challenged with 5 g of MSG and with placebo without food (protocol A): 50 (38.5%) responded to MSG only, 17 (13.1%) to placebo only and 19 (14.6%) to both. Rising doses raised response rates, but only 19 of 37 MSG-only responders reacted the same way on retest; the 2 people who then responded to MSG but not placebo twice were challenged 3 times each with 5 g of MSG and with placebo in the presence of food, and each responded to only one MSG challenge. Conclusion: large doses without food may elicit more symptoms than placebo in people who believe they react, but no persistent or serious effects were seen and responses were not consistent on retesting (abstract, PMID 11080723). 10.1067/mai.2000.110794
U.S. Food and Drug Administration. (2026). Questions and answers on monosodium glutamate (MSG) (content current as of 17 July 2026). FDA considers the addition of MSG to foods 'generally recognized as safe' (GRAS). Adverse event reports led FDA to ask FASEB to examine MSG safety in the 1990s; FASEB's report concluded that MSG is safe, and identified short-term, transient and generally mild symptoms (headache, numbness, flushing, tingling, palpitations, drowsiness) that may occur in some sensitive individuals who consume 3 grams or more of MSG without food; consuming more than 3 grams of MSG without food at one time is unlikely. An average adult eats about 13 g of glutamate a day from food protein, against about 0.55 g a day of added MSG (Q&A page, read 2026-09-25). www.fda.gov/food/food-additives-petitions/questions-and-answers-monosodium-glutamate-msg
Jinap, S., & Hajeb, P. (2010). Glutamate: its applications in food and contribution to health. Appetite, 55(1), 1-10. Reviews glutamate/umami in food and the use of MSG to reduce added sodium while maintaining palatability. 10.1016/j.appet.2010.05.002
National Academies of Sciences, Engineering, and Medicine. (2019). Dietary Reference Intakes for Sodium and Potassium. National Academies Press. The PubMed book abstract (PMID 30844154) gives no reference values; it says the report updates the sodium and potassium DRIs with an expanded model that adds chronic-disease endpoints (the Chronic Disease Risk Reduction Intake). The numeric AIs and CDRRs were not re-read for this note (abstract). www.ncbi.nlm.nih.gov/books/NBK538102