Is MSG A Neurotoxin? Fact Vs. Myth


Monosodium glutamate (MSG) is the sodium salt of glutamate, the most common naturally occurring amino acid. It is used as a food additive, and confers the protein-like flavor (amino acids are the building blocks of proteins) called umami to foods when used in the proper proportions.

Since the 1970s the use of MSG to flavor foods has been controversial. Many people report symptoms of what came to be known as “Chinese Restaurant Syndrome,” which can include headache, flushing, numbness, and weakness.

While MSG is typically blamed for these complaints, the high concentrations of salt, sugar, and gluten typical in American Chinese restaurants should also be suspect. Indeed, even after several double-blind placebo controlled studies, scientists have failed to establish any link between MSG consumption and the symptoms described.

While certain people may be sensitive to MSG ingestion, most experts consider the condition to be rare and some even question its existence.

It has also been suggested that MSG can lead to acute neurotoxicity. These fears arose from a study showing that neonatal mice that were injected with or force fed very high doses of MSG suffered from brain lesions. While this may sound alarming, the same toxicity did not occur when the MSG was administered with food, even at high doses.

That the toxicity does not occur in the presence of food should be reassuring, but evidence shows that the danger is even less significant for humans. Mice are particularly sensitive to MSG, and even much higher doses of orally ingested MSG are safe for human adults and babies.

Probably the biggest concern for ingesting substantial amounts of MSG is that it increases palatability (that’s the scientific term for tastiness) of foods and can encourage overeating. However this effect may actually be beneficial in patient groups who have trouble getting sufficient nutrition, such as cancer patients and the elderly.

To summarize, while foods that contain high doses of MSG are rarely healthy, MSG itself does not contribute to health problems.

When it comes to the science of wellness, distinguishing the facts from the urban legends can be tough. That’s why we’ve enlisted Darya Pino – a scientist, foodie, and self-proclaimed geek girl. Check out the ZocDoc Blog every Tuesday to see her bust the biggest myths in health.

Image: Best Dumplings in the World, a Creative Commons Attribution (2.0) image from Stewart’s photostream.

  • waragainstlibs

    scientists believe that primates are susceptible to excitotoxic damage[26] and that humans concentrate excitotoxins in the blood more than other animals.[27]
    Based on these findings, they claim that humans are approximately 5-6
    times more susceptible to the effects of excitotoxins than rodents are.[28]
    While they agree that typical use of monosodium glutamate does not
    spike glutamic acid to extremely high levels in adults, they are
    particularly concerned with potential effects in infants and young
    children[29] and the potential long-term neurodegenerative effects of small-to-moderate spikes on plasma excitotoxin levels.[30]

  • LaLaLu

    This is such garbage. I have a husband who gets migraines from MSG and a son who gets seizures. Documented, specific to this neurotoxin.

    • googoodolls

      So your husband and your son have actually been given a placebo and MSG in the same situations and the migraine and seizure only occur in the case when they have MSG. And how many times has this test been done. If this is documented please send me the link to this peer reviewed study.

      • Kim Kremer

        It’s a pity so few people understand the difference between anecdotal evidence and empirical evidence.

        • Mary Anne Schiavone Daly

          I have MSG sleeplessness and headaches. I am not stupid and I never know when eating at a restaruant when I will be able to sleep that night. Take this as the fact of one person; I’m am only one data point, and do not require a double blind test to have experienced MSG issue for 25 years. It’s time to stop with the sophistry. The MSG thing is starting to sound like the cigarette alibis in 1965. That took 50 years for there to be enough “science” to match the common sense experience of normal people. If the stuff was safe – didn’t do something bad for so many people – there wouldn’t be 50 years of complaints about MSG.

        • DiaconRadish

          Yeah msg has been in the Asian diet almost 100 years in (since 1909) yet they are the epitome of a healthy society…. Hmmm and these “reliable” anecdote comes from Americans who experienced these symptoms from Chinese restaurants that are extremely more unhealthy than the cuisine from the country it’s trying to imitate??? Riiiiggghhhttt….

        • Kim Kremer

          I am not calling you stupid. What happens to you is real and I would never tell you it didn’t happen. But that’s anecdotal evidence, not empirical evidence.
          When I take muscle relaxants, I get weird, psychotropic side effects that are not listed as potential side effects – not even in the “vanishingly rare” side effects. That does not mean I do not experience them.