“MSG is bad for you!” — How a made-up scientist trolled us in thinking it is.
“MSG is unhealthy for you!”, “Glutamate is Poison!”, “No added MSG.”. I am sure you heard that before. But why do we keep hearing that it is? Well, that’s a really strange story, about racism, food marketing, classical media clickbait and at its core a “scientist” that trolled us all.
But first, let’s start with a few basics.
The basics — What is Glutamate?
Glutamate is a colorless salt that can be used in cooking. On its own it doesn’t taste like much. A bit hearty, rather like bland chicken broth.
It is the salt of glutamic acid. One of the 20 canonical amino acids that make up all of our proteins. Glutamic acid or glutamate occurs naturally in many foods and is also produced by our body. That means that for man-eating animals and for cannibals we are also foods containing glutamate.
In this pure form, glutamate was first isolated from algae in 1908 by the Japanese chemist Kikunae Ikeda. During a research stay in Leipzig, Germany, Ikeda discovered that some German foods — tomatoes, asparagus, cheese, meat — had a very special flavor. Special flavor … German food, seriously? Yes!
Ikeda not only identified this particular taste in certain German dishes, but also recognized it in Japan, for example in Dashi. Dashi is a strong broth, traditionally made with Kombu algae. This characteristic, hearty taste found in meat, dried tomatoes, parmesan or dashi is called Umami. In addition to sweet, salty, sour and bitter, Umami is the fifth flavor and means ‘delicacy’ in Japanese.
Nerd fact: I am talking about the main flavors that we really perceive with the main receptors on the tongue. In addition, there are of course a lot of different aromas, but we mainly absorb them through the nose.
In 1909 he brought glutamate onto the market in the form of its sodium salt. Monosodium Glutamate, MSG for short. MSG made the pure Umami taste available and started it’s triumph in kitchens around the world.
Why do we love the Umami flavor of MSG so much?
Wikipedia describes Umami as meaty, spicy (not in the meaning of hot, rather ‘many spices used’) and tasteful. Since Umami is more difficult to describe and identify than other flavors, it was not sure to classify it as an own distinct flavor for a long time. Although this is now being done, this classification is still being discussed¹. However, Umami receptors actually exist on our tongues. Some substances — aspartate, inosinate, guanylate, and glutamate — activate these Umami receptors. Just like sodium chloride activates our salty receptors, or sugars activates our sweet receptors.
Surprisingly, the pure Umami taste is very mild in contrast to our perception of salty or sweet. Only in combination with other aromas does the flavor-enhancing effect come through.
In a study², participants were given a glutamate inosinate solution to drink — so to speak, a pure MSG shake — and at the same time let them sniff a vegetable aroma. The Umami taste or the vegetable aroma alone were both rated as not so great. But in combination it resulted in a more pleasant taste/smell experience. This could even literally be seen in brain scans. With the combination of Umami drink and vegetable aroma, the brain activity was stronger than the sum of the two individual doses.
Nerd fact: Speaking of Brain — Glutamate is also a neurotransmitter. In other words, one of the molecules that brain cells use to communicate with one another. For those who are worried that glutamate could mess up neurochemistry: Glutamate that we ingest through food doesn’t easily get into the brain, due to the blood-brain barrier. A barrier between the central nervous system and the bloodstream that only allows certain substances to pass through. In 1885, Paul Ehrlich showed that a blue dye injected into the bloodstream of a dead animal stained the entire body blue, except for the brain. Later, an Ehrlich student demonstrated the opposite, namely that staining the brains of dead animals blue did not stain the rest of the body³.
Glutamate is not fundamentally harmful, it is actually even a substance that is familiar to the body. But, as with sugar or salt, could the dose make the poison? Yes, there could be something to it.
The downfall starts with a trolling “scientist”
It all started with a letter to the editor in a medical journal. Well, it was rather just some kind of troll post.
In 1968 this “letter to the editor” was printed in the renowned “New England Journal of Medicine”, in which primarily medical studies were published⁴. A Sino-American doctor named Robert Ho Man Kwok described that he noticed certain physical symptoms, always after going to a Chinese restaurant.
Numbness in the neck that continues towards the arms and back, general weakness, tiredness and palpitations. He speculates about possible triggers, including glutamate. The proposed whether his colleagues wouldn’t want to research this topic more closely. The whole thing was called “Chinese Restaurant Syndrome”. You have heard about it already.
For their part, several medical professionals replied in letters to the editor that they felt the same way⁵. They reported that they too noticed certain symptoms after visiting a Chinese restaurant. Soon later the “New York Times”⁶ reported about the “Chinese Restaurant Syndrome”, which doctors apparently had discovered.
A number of scientific studies followed that led to various concerns about MSG. Headache, stomach ache, nausea, obesity, risk of Alzheimer’s or Parkinson’s and much more. However: Many of these studies were, for example, animal experiments in which extremely high doses of glutamate were injected directly into the abdomen⁷.
Of course, that doesn’t have that much to do with how MSG is used in the kitchen. I mean have you been injected high amounts of MSG into your belly in any restaurant? The only thing one can deduct from that particular study is: Please do not inject high doses of glutamate.
Studies on MSG: The Good, the Bad and the Ugly
Nevertheless, there were studies with people. But those studies were methodically flawed. Either because they were only question-based: “Do you suffer from Chinese Restaurant Syndrome?” “Yes.” “All right.” Or studies that weren’t blinded experiments. Hence participants knew whether they were consuming glutamate or not. Knowing that you are ingesting something potentially harmful can easily lead to the nocebo effect.
Need fact: The nocebo is the negative brother of the placebo effect, where the expectation of side effects alone can lead to headaches or abdominal pain.
On the bright side, over time, methodically correct studies began to accumulate, in which, for example, a test group was given a glutamate tablet and the control group a placebo tablet⁸.
Nerd fact: This study is an example for a well-made blinded experiment. Neither the participants nor the participating scientists knew who got the glutamate or placebo. Only after all results had been recorded, it was revealed.
And surprise, no significant effect was found. And even studies with people who reported glutamate intolerance themselves produced mixed and mostly non-reproducible results⁹.
In short: Fear of MSG, especially in the quantities in which it is used as a flavor enhancer, is just that — fear. Without any scientific evidence.
But wait a second … Does that mean some are trying to avoid glutamate just because some doctors exchanged anecdotes about abdominal pain in 1968? Well… yes, you can see it that way. But it gets better.
Fake claims from a fake scientist?
It’s not even certain that Robert Ho Man Kwok really existed. As I said, the “New England Journal of Medicine” is a renowned journal. But this correspondence part, in which these letters to the editor were printed, was back then … well, almost like a kind of Reddit board for medical professionals. Much of what was published was written with a twinkle in the eye. For example, there was almost a kind of tradition of inventing fake symptoms or exaggerating them in order to amuse oneself. Today we would call it trolling or memes.
But here comes the kicker: There are a few articles that report that Dr. Ho Man Kwok was just actually just a made-up name by another physician — Dr. Howard Steel¹⁰.
According to Steel, he wrote the letter as a joke at the time, and assumed that it would be clear to everyone that it was one of those “funny” posts. The name Ho Man Kwok is said to have been a play on words. Did you get it? Human crock. An abbreviation for “human crock of sh*t”. In any case, it should be obvious that the whole thing wasn’t meant seriously. You can even find a few letters in reply who have recognized and absorbed this play on words with Crock.
However, if this explanation in itself is fake or real is also not certain. It’s all based on what Howard Steel said. Apart from that, there is no further evidence to be found.
It’s very much a strange story. But it doesn’t really matter whether it’s really fake or fake fake. Main point is, those letters were definitely not a professional exchange based on scientific evidence — it was plain trolling.
How “No MSG added” labels shaped our opinion
Only from the outside, was the whole thing perceived as correspondence between medical experts. Media reports like that of the “New York Times” quickly fell on the fertile soil of general anti-Asian racism in public. Chinese food, for example, was often portrayed as gross or unclean anyway: “They eat rats and dogs.”
Certainly some of the medical professionals who had started the whole debacle with their letters were not exempt from these prejudices. More on the communication debacle you can find here¹¹.
When the results of questionable glutamate studies began to circulate, the fear of MSG was established. And what happens then? Food manufacturers and restaurants followed the money-making trend and started to advertise with “No added MSG”. Ironically, many products contain naturally high amounts of glutamate. They are by no means MSG-free, therefore they are labelled “No added MSG”. It is a bit misleading, but technically correct. One doesn’t need to add MSG, when it is already in.
Nevertheless, the “No added” labeling again shaped our opinion: Glutamate has to be bad, otherwise they wouldn’t advertise it like that, right? This is how we ended up here today.
But I would argue that in some cases glutamate may not only be not bad, it may even be good, when used as a spice. Just like salt or sugar.
The positive: MSG can be used to your benefit
Since glutamate can also make fresh vegetables tastier, it is a great help to eat more vegetables. And even with vegan meat substitute products, Umami substances such as glutamate, yeast extract or the like are of course essential for the Umami meat-like, hearty taste.
The taste enhancing effect of MSG is perfect for someone that might like to eat less meat, but struggle with it because they like meat so much. One can be grateful for Umami food science, that meat substitute products are getting better and better and thus perhaps also make it easier to eat less meat.
However, there is some fear, which is currently also being investigated, that glutamate could be linked to obesity. The reasoning behind this can be broken down into: If something tastes particularly good — and glutamate makes food tastier -, then one may eat more of it than one should.
This is also a possible explanation for post-meal abdominal pain. Glutamate is often used in finished products or in unhealthy snacks such as crisps, often in the form of yeast extract. That said, there is something to the rule of thumb, avoiding glutamate in order to eat healthier. But it’s not the glutamate itself, but rather the foods to which glutamate is added.
Conclusion — the final verdict
MSG fell into disrepute for no scientifically proven reason. It traces back to a “joke” that spiraled out of control, heated-up by fast media that did not check the facts or background of the claims. In the amounts we are eating it already as part of a normal diet as well as an additive to food as MSG powder, there is no health risk associated.
Until then, stay healthy and fit! :)
¹: Umami as an ‘Alimentary’ Taste. A New Perspective on Taste Classification.
²: Umami: a delicious flavor formed by convergence of taste and olfactory pathways in the human brain.
³: Trypan blue dye (1913).
⁴: Chinese-Restaurant Syndrome.
⁵: Hearings, Band 3.
⁶: ‘Chinese Restaurant Syndrome’ Puzzles Doctors.
⁷: Monosodium glutamate: Review on clinical reports.
⁸: The Safety Evaluation of Monosodium Glutamate.
⁹: Review of Alleged Reaction to Monosodium Glutamate and Outcome of a Multicenter Double-Blind Placebo-Controlled Study.
¹⁰: The Strange Case of Dr. Ho Man Kwok.
¹¹: Uptaking Race: Genre, MSG, and Chinese Dinner.
All pictures provided by pexels or self-made. Thank you :).