The claimEvidence A · guideline-tier
MSG is toxic ('Chinese Restaurant Syndrome')
The evidence
Originates from a 1968 uncontrolled letter; Geha 2000 double-blind challenge found only 2.3% responding, non-reproducibly — glutamate is the same molecule as in tomato and breast milk, safe at dietary doses.
The mechanism, in brief
After Kwok's letter, researchers spent decades testing 'MSG causes symptoms' under double-blind, placebo-controlled conditions. The conclusions are consistent:
Sources (2)
- 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.
- 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.