Popular YouTuber Alex Jones claims (in a YouTube video with nearly 1M views) that MSG is an excitotoxin and harms the brain and liver.

I haven't even had time to get into MSG. I mean, I've interviewed brain surgeons, neurologists, scientists. I mean, it just devastates the brain. It is an excitotoxin. It destroys the liver.

Is MSG an excitotoxin?

  • 1
    Given that we can't even demonstrate that MSG has objective effects when consumed (unsurprisingly given that glutamate is a major component of every bodily protein) this seems unlikely. See the answers to this question.
    – matt_black
    Nov 20, 2016 at 10:56

1 Answer 1


There doesn't seem to be any evidence for this.

Here is one study:

Conventional toxicity studies using dietary administration of MSG in several species did not reveal any specific toxic or carcinogenic effects nor were there any adverse outcomes in reproduction and teratology studies. Walker & Lupuien, 2000. The safety evaluation of monosodium glutamate.

This is what the FDA has to say:

The Select Committee notes that the new information on long-term oral administration of monosodium glutamate (MSG) in the diet to various animal species has revealed no adverse effects
There is no evidence in the available information on L-glutamic acid, L-glutamic acid hydrochloride, monosodium L-glutamate, monoammonium L-glutamate, and monopotassium L-glutamate that demonstrates, or suggests reasonable grounds to suspects, a hazard to the public when they are used at levels that are now current and in the manner now practices. FDA SCOGS, 1980.

Here is a statement by a German commission, which is specifically about the effects of MSG on the brain (it also cites a number of previous studies which you can look up as well):

Frühere Bewertungen (WHO, 1988; SCF, 1991; FASEB, 1995, FSANZ, 2003; NAS, 2002) haben ergeben, dass bei Verwendung der üblichen Mengen an Glutamat in Lebensmitteln neurotoxische Wirkungen nicht zu befürchten sind. Die Senatskom- mission schließt sich dieser Auffass ung aus folgenden Gründen an:[...]Eisenbrand, 2005. Stellungnahme zur potentiellen Beteiligung einer oralen Glutamat-Aufnahme an chronischen neurodegenerativen Erkrankungen

My translation: Earlier evaluations (WHO, 1988; SCF, 1991; FASEB, 1995, FSANZ, 2003; NAS, 2002) have shown that there is no reason to worry about neurotoxicity from the use of usual amounts of MSG in food. This commision agrees with the evaluation.

The report also notes that endogene glutamate are associated with neurological issues such as alzheimer, MS, parkinson, or ALS. It specifically points out that this is not the case for exogene glutamate (ie glutamate that is eaten). The report mentions that this is the case because glutamat cannot pass the blood–brain barrier very well.

For more information about the general safety of MSG you can also look at the sources of the wikipedia article, which cites numerous studies.

So it may be possible that Jones did indeed interview neurologists, but misunderstood what they said. As he is a conspiracy theorist, it is also possible that he just made it up himself.

  • 2
    He's quoting an actual (retired) neurosurgeon, Russell Blaylock, in that video, so not made up by Jones. However according to Wikipedia Blaylock holds some stereotypically crank opinions in other fields including chemtrails, anti-vax, fluoridated drinking water, so some more convincing evidence would help. Nov 19, 2016 at 1:05
  • Note that while he says he's interviewed neurologists, he doesn't actually finish with "... and they said that MSG is bad", he just structured his phrasing to imply that without saying it outright. This is verbal sleight-of-hand used when you want to give an impression of authority-by-proxy that you don't actually have.
    – Shadur
    Nov 21, 2016 at 13:55

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