The Spice Lab · Experiment 34
Is MSG (ajinomoto) actually bad for you?
MSG carries a fearsome reputation, headaches, "Chinese restaurant syndrome", a chemical to fear. Decades of rigorous research tell a very different, and much duller, story.
is all MSG really is
MSG is just sodium plus glutamate, the very amino acid that makes tomatoes, cheese and mushrooms taste savoury. The "Chinese restaurant syndrome" scare has not held up.
Ask around and MSG is a villain: the mystery powder behind the post-takeaway headache. It is one of the most studied food additives in existence, and the science has quietly exonerated it for years.
What MSG actually is
MSG is monosodium glutamate, the sodium salt of glutamate, a common amino acid. Glutamate is not exotic: it is abundant naturally in tomatoes, parmesan, mushrooms, seaweed and even breast milk, and it is the taste we call umami. MSG simply delivers that same molecule in a convenient form.
Where the fear came from
A single 1968 letter coined "Chinese restaurant syndrome", and decades of anxiety, headaches, numbness, followed, wrapped up in a fair amount of cultural prejudice about Chinese food.
What the research found
Rigorous double-blind trials have not reliably reproduced those symptoms from normal dietary amounts of MSG, and food-safety authorities classify it as safe for the general population.1 A small minority may react to very large doses on an empty stomach, but even that evidence is weak.
The boring, real caveat
The one true point is sodium, but it cuts the other way: MSG contains only about a third of the sodium of table salt per gram, so using a little MSG can actually deliver savoury flavour with less total sodium. It is a flavour enhancer, not a poison, and not a health food either.
Free glutamate is everywhere
natural sourcesGlutamate, the savoury molecule in MSG, occurs abundantly in everyday foods. It is the same molecule.
What this means in your kitchen
Use MSG, or not, on taste, not fear.
- 1
Use MSG for umami if you like it
It is safe in normal amounts and deeply savoury.
- 2
It can lower your total sodium
A little MSG seasons with about a third of salt's sodium.
- 3
Remember it is a natural molecule
The same glutamate is in tomato, cheese and mushroom.
- 4
Sensitive to large doses? Use less
The evidence is weak, but there is no harm in easing off.
- 5
Treat it as a flavour enhancer
Not a health food, not a hazard.
The myth
"MSG is a dangerous chemical that causes headaches, avoid it."
The fact
MSG is just sodium plus glutamate, the same umami amino acid in tomatoes and cheese. Rigorous trials do not back "Chinese restaurant syndrome". It is safe, and lower in sodium than salt.
How strong is the evidence?
We rate each claim separately, because they are not equally proven.
Glutamate is a natural amino acid in common foods (Strong)
Abundant in tomato, cheese, mushroom and more.
Double-blind trials do not reproduce "MSG symptom complex" (Strong)
Extensively studied; symptoms not reliably reproduced.
MSG has less sodium than salt per gram (Strong)
About a third; can reduce total sodium.
"MSG is toxic or causes disease" (Not supported)
No credible evidence at dietary intakes.
This is educational content, not medical advice.
In one minute
- MSG is sodium plus glutamate, the umami molecule in tomatoes and parmesan.
- Rigorous trials do not support "Chinese restaurant syndrome".
- It is safe, and, having less sodium than salt, can even cut your salt.
Sources
- Freeman M. Reconsidering the effects of monosodium glutamate: a literature review. J Am Acad Nurse Pract. 2006;18(10):482-486.
- FASEB / US FDA. Analysis of adverse reactions to monosodium glutamate. 1995.
- Zanfirescu A, et al. A review of the alleged health hazards of monosodium glutamate. Compr Rev Food Sci Food Saf. 2019;18(4):1111-1134.