If you have eaten any processed foods over the past few decades, chances are you have ingested the controversial flavor enhancer monosodium glutamate (MSG).
MSG is a sodium salt created from glutamic acid. Although most commonly associated with processed foods and Chinese takeaway, MSG is a naturally occurring substance in many deliciously savory foods such as cheese, tomatoes, and soy — but the manufactured version is the type that draws the most negative attention.
As a chemical compound capable of enhancing the savory or meaty flavors of food (a taste sensation now labeled as umami), it is no surprise that MSG was quickly adopted by restaurant owners to make their food stand out to customers. While MSG was used in a variety of cuisines, Chinese food is most commonly associated with it.
The ingredient was rampantly used in foods from the 1900s to the 1960s, but the controversy surrounding MSG quickly changed the public’s opinion of MSG. A single medical article written in 1969 began a decades-long controversy labeling MSG as a toxin, but this has recently been unfounded by modern research.
After years of use to suddenly being added to the food blacklist, MSG is finally returning to the spotlight — and it’s about time that we finally put to rest the stigma against this additive.
Before we dive into the fluctuating popularity of MSG over the years, let's look at the type of flavor it can add to food.
In grade school, you probably learned about the four basic tastes: sweet, salty, sour, and bitter. While these four tastes are simple to understand and cover many of the different flavors we experience, there is one missing from this list — umami (pronounced ooo-maa-mee).
Often described as a meaty, savory flavor, the word umami is Japanese for 'the essence of deliciousness.'” Just like the other four tastes, umami has distinct characteristics that define its unique flavor:
The umami taste often spreads across the entire tongue, filling the mouth with the delicious flavor.
Foods high in umami are known to produce a mouth-watering sensation, increasing the amount of saliva in our mouth as we enjoy the full flavor.
Umami lasts longer than any of the other core flavors, which may explain why people find umami-rich foods so delicious.
In most cases, umami taste is derived from the presence of glutamic acid (either naturally occurring or added) in food. First identified in 1866 by chemist Karl Heinrich Rittausen, glutamic acid and its connection to umami were not fully understood until multiple decades later in Japan.
In 1908, researcher Kikunae Ikeda of the Tokyo Imperial University was the first person to isolate glutamic acid as the source of a specific taste.¹ During his research, Ikeda extracted glutamic acid from konbu (Laminaria japonica, a type of seaweed), which resulted in a pleasant, savory taste. This specific taste was not something that Konbu could describe as sweet, sour, bitter, or salty — and thus, he labeled the fifth true taste as umami.
Through further research of the unique properties of the calcium, potassium, and magnesium glutamate salts, Ikeda found that monosodium glutamate (now known as MSG) was the easiest to stabilize and crystallize. Ikeda filed for a patent to produce MSG, and in 1909, the flavor enhancer was available for commercial purchase.²
In the years following its discovery, MSG took the culinary world by storm. As it can create delicious savory dishes, many restaurants (particularly Chinese food vendors) began to use MSG as an additive because it made their food more appealing to a wider audience.
Unfortunately, trouble started to brew for MSG in the 1960s when biochemist Dr. Robert Ho Man Kwok had an apparent reaction to some Chinese food. In his letter to the New England Journal of Science in 1968, Dr. Kwok claimed that after eating Chinese food containing MSG, he experienced a variety of symptoms, including lightheadedness, pain, and general body aches.³
In the now-infamous letter, Dr. Kwok referred to his symptoms as “Chinese Restaurant Syndrome” — blaming the high amounts of MSG used by many Chinese restaurants as the primary source of his illness. The following edition of the journal contained a published article by Dr. Kwok, which elaborated further on the apparent toxic nature of MSG and highlighted even more potentially hazardous side effects of consumption. Some of the reportedly dangerous symptoms included burning sensations, facial pressure, and chest pain — all of which have never been verified by modern research.⁴
Unfortunately, once the general public heard of 'Chinese Restaurant Syndrome,' food providers who regularly used MSG could not continue to do so. Producers of packaged and processed food removed MSG from their products, and many Asian restaurants started labeling their foods 'MSG-free' to maintain business.
After the article was published, the world seemed to turn its back on MSG — essentially blacklisting it. Interestingly, during this time, the US Food and Drug Administration (FDA) maintained MSG's safe status. It had also been previously found in high quantities in the average US citizen's food cupboards for decades without no issue.⁵
With one single letter, Dr. Kwok changed the global opinion of MSG seemingly overnight. Interestingly, research studies conducted after the infamous Dr. Kwok letter have never been able to validate any of his claims. Since then, some researchers have suggested that his symptoms may have been psychosomatic — physical symptoms resulting from internal stress, so MSG was likely not responsible for any of his symptoms.
Ajinomoto (the leading provider of MSG worldwide since 1909) was naturally eager to dispel the negative association and rumors surrounding their product. To do this, they had to first tackle the stigma surrounding 'Chinese Restaurant Syndrome.'
The Redefine CRS campaign was set up, and its goal was to educate people in Western society about the safety of MSG while breaking down problematic and discriminatory thinking surrounding Chinese Restaurant Syndrome.
Through the campaign, well-known Asian-American chefs, medical professionals, and public figures spoke out about the most common misconceptions surrounding MSG. The campaign educated people about MSG’s controversial past, promoted research findings debunking Dr. Kwok’s claims, and brought awareness to the unfair amount of blame that the term 'Chinese Restaurant Syndrome' puts on specific groups of people and their food.
After weeks of active campaigning, Ajinomoto convinced the Merriam-Webster dictionary to update its definition of 'Chinese Restaurant Syndrome' to be more inclusive, more accurate, and less offensive.
While the best-known form of MSG is the manufactured version that can be added to food, MSG is also a naturally occurring substance in some of our favorite foods. It is found as an amino acid in flavorful foods such as cheese, tomatoes, mushrooms, yeast extract, anchovies, and many cultural foods around the world.
But is this naturally occurring version of MSG any better than the manmade option that garnered so much attention? The answer is no — and both options may be able to offer some additional health benefits.
MSG packs a powerful punch of the rich umami taste, and foods flavored with MSG are satisfying to eat. While other seasonings often rely on higher doses of sugar or salt (both of which can have negative health impacts in large doses), MSG can help to enhance the flavor of food without the extra calories or health risks.
Recent research funded by Ajinomoto found that adding MSG to foods could help reduce the average American’s daily sodium intake by up to 8%.⁶ Despite being partially made from sodium, MSG contains only about a third of the sodium found in traditional table salt, so it helps to reduce salt intake.
Traditional salt is a popular additive found in processed and fried foods, despite the fact that eating high amounts of sodium has been linked to an increased risk of developing hypertension, heart disease, and stroke.⁷ So, by increasing the amount of MSG used in our foods, we may actually be creating healthier options.
Looking to validate (or invalidate) Dr. Kwok’s bold claims, many researchers have conducted studies about MSG to finally discover the truth about the safety of this delicious food additive.
Conducted by different researchers around the world, some of the most recent research that defends the safety of MSG includes:
A 1986 research paper published in the Food and Chemical Toxicology Journal concluded that after a decade of research, they were unable to find any objective sign that MSG was toxic for humans.⁸
As part of an independent inquiry conducted by the FDA in the 1990s, it was found that MSG is “generally recognized as safe.”⁵
In a joint study by the World Health Organization (WHO) and the United Nations Food and Agriculture Organization (FAO), researchers were unable to find a definitive link between MSG and described Chinese Restaurant Syndrome symptoms.⁹ A large part of this conclusion stems from the fact that all reports of Chinese Restaurant Syndrome are anecdotal (based on stories from the people who experienced it), which makes proving the condition difficult.
The technical report on MSG from the Food Standards Australia and New Zealand (FSANZ) concludes that: “There is no convincing evidence that MSG is a significant factor in causing systemic reactions resulting in severe illness or mortality. The studies conducted to date on Chinese restaurant syndrome (CRS) have largely failed to demonstrate a causal association with MSG.”¹⁰
MSG has traveled a bumpy road in the eyes of the general public over the past century. From an initially beloved additive widely used for nearly six decades to a feared and hated “toxin” that was to be avoided, it is clear that MSG is finally on its redemption tour as it re-enters the spotlight.
While new research and awareness about the safety of MSG are slowly contributing to its acceptance again, MSG is still unfortunately used as a pawn in continued discrimination and racism against Chinese food and culture. As a seasoning that has effectively been vilified and perceived as toxic by the Western world for decades, correcting the storyline around MSG cannot be achieved overnight.
Now, with more information about its safety circulating on the internet, MSG and those who value it as a seasoning in their food are finally beginning to be accepted again. While more work remains to dispel the powerful rumors created from a single letter in the 1960s, MSG is finally getting the attention and recognition it deserves as a delicious, safe umami seasoning, perfect for adding to a variety of our favorite foods.
History of glutamate production | The American Journal Of Clinical Nutrition
The first 100 years of the Ajinomoto group | Ajinomoto Group
Monosodium L-glutamate: Its pharmacology and role in the Chinese restaurant syndrome | The National Library of Medicine
The strange case of Dr. Ho Man Kwok | Colgate Magazine
Questions and answers on monosodium glutamate (MSG) | The U.S. Food & Drug Administration
Sodium | Center for Disease Control and Prevention
The Chinese restaurant syndrome: An anecdote revisited | The National Library of Medicine
The safety evaluation of monosodium glutamate | The Journal of Nutrition
MSG technical report | Food Standards Australia and New Zealand
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