In 1908, Japanese scientist Kikunae Ikeda returned home from Germany, where he appreciated the savory taste of the local cuisine.
A bowl of kombu seaweed soup revealed the same sense of savory — the taste sensation now known as umami — so he boiled down the seaweed to find out what gave it that taste. His discovery created an ingredient that is known to add a more complex umami flavor to dishes and found its way into processed foods across the world.
But that ingredient, monosodium glutamate, also earned itself a spot on many consumers' lists of food components they avoid at all costs. A 1968 letter to the editor of the New England Journal of Medicine from Dr. Robert Ho Man Kwok, a physician who complained of headaches, dizziness and general weakness after eating at Chinese restaurants, led to the negative perception of the ingredient. In his letter, Kwok concluded those negative impacts had to come from the MSG that restaurants added to the food.
And just like that, consumers started looking to avoid MSG. It doesn't matter that MSG has always had generally recognized as safe status from the FDA, or that Kwok's letter cited no scientific evidence. They also didn't care that the only research that found consistent negative effects of MSG consumption involved extremely high doses of the ingredient while feeding mice or injecting monkeys. Or that for almost six decades before then, MSG was found in pantries all over the United States and used to season all kinds of dishes without common reports of negative impacts.
For decades, many scientific studies have been dedicated to proving MSG is safe to consume. Kantha Shelke, a food scientist and founder and principal of consulting firm Corvus Blue told Food Dive in an email that the stigmatization of MSG has been an "unnecessary source of anxiety for consumers."
"It is an unfortunate truth that people tend to be less trusting of the unfamiliar, and are more likely to be influenced by peers and garrulous activists when evaluating the risk of unfamiliar ingredients than trusting scientific evidence from food risk and safety experts," Shelke wrote.
But what many consumers likely didn't know is that MSG has been in countless products all this time. According to FDA figures, the average American eats about half a gram of MSG daily. It's commonly used in snack products, ranch dressing, condiments and soups. Ac'cent seasoning is 100% MSG. According to Ajinomoto — the company started by Ikeda in 1909, which is responsible for about 70% of the U.S. MSG market — sales are increasing about 5% each year.
As younger Americans get more interested in savoring flavor, authentic international tastes and knowing exactly what is in their food, MSG is seeing a bit of a resurgence. When the "chicken sandwich wars" heated up between fast food restaurants, McDonald's, Popeyes and Chick-fil-A all admitted to including MSG in their premier items. And while numerous media outlets have covered these restaurants' use of the ingredient, it isn't stopping consumers from using it nor deterring them from eating the sandwiches.
Tia Rains, senior director of public relations for Ajinomoto Health & Nutrition North America, told Food Dive that millennials and Gen Zers may be driving this change.
"I think this younger generation in particular are the ones that are more receptive and more open, and are like, 'I don't understand why, you know? What was the big deal?'" Rains told Food Dive. "And they didn't grow up as much with the 'No MSG' signs, and so they're just much more open to looking at facts when presented with the fact in a way that resonates with them. So I do think things are finally changing."
What is MSG?
With its chemical-sounding name and a reputation for causing negative effects, it's easy to assume that MSG is something that was synthesized in a lab.
However, Rains said, it's actually a pretty simple and naturally occurring compound. Back in 1908, when Ikeda boiled down the kombu, he discovered that the savory taste came from glutamate — one of the 20 amino acids that makes up all proteins. Ikeda wanted to turn this sense into a seasoning, so he tried combining it with different salts. And sodium was the clear winner, providing the best crystal structure, the best solubility and the most stability.
"It is an unfortunate truth that people tend to be less trusting of the unfamiliar, and are more likely to be influenced by peers and garrulous activists when evaluating the risk of unfamiliar ingredients than trusting scientific evidence from food risk and safety experts."
Principal and founder, Corvus Blue
Ajinomoto currently makes its MSG for the United States at a factory in Eddyville, Iowa — right in the middle of corn country, Rains said. It's currently fermented from sugar that's refined at Cargill's plant in the same town. The fermentation happens in large tanks, then Ajinomoto isolates the glutamate and adds the sodium. The solution is air dried and becomes MSG crystals.
Rains said that the leftover material, called the broth, is turned into animal feed in the United States. Similar processes for making MSG in other countries turn the leftovers into fertilizer. But the process shows that MSG meets two of the biggest food trends: It's clean label and sustainable.
"We've found ways to sort of reuse everything so that it is this circular process where everything gets utilized or upcycled into something else," she said.
What is MSG good for?
MSG is a perfect seasoning for creating umami, the savory fifth taste sensation that Ikeda discovered and named through his research.
The seasoning is often associated with Asian food. This could be because of Ikeda's nationality or the kombu he used to discover the taste's source. It could also stem from Kwok's letter, which spawned the term "Chinese restaurant syndrome." The term actually appears in the dictionary, defined as the ill effects he described and attributed to consumption of MSG in Chinese food.
But the glutamate that brings this sensation is naturally a part of many foods from around the world. Ikeda first noticed the umami taste in German food, and traditional dishes like sauerkraut are packed with it. But food items including Parmesan cheese and many mushrooms also contain high concentrations of glutamate, producing the umami sensation.
MSG is added to many processed foods today to make them taste more craveable and savory, but Rains said there are some other beneficial applications of the seasoning. It's an effective sodium reducer, she said. Research funded by Ajinomoto that appeared in the journal Nutrients last year found that MSG could reduce the average American's sodium intake by about 8%. While MSG contains sodium, it has about a third of that in table salt, the study says.
Wider use of MSG could help many food companies meet the voluntary sodium reduction guidelines put in place by FDA, which seeks to reduce the average American's sodium consumption by about a third by 2025, Rains said.
"I'm hopeful that with the science backing that, it will get recognized for especially some vulnerable populations that really do need to watch their sodium intake," she said. "You've got some experts out there that are really not encouraging it, but are basically saying, 'You know, it's a tool in the arsenal that can be used to have this benefit.'"
Rains said there is also pending research that looks at MSG as a flavoring for plant-based meat. According to a white paper from Kerry, authentic taste is the top barrier to people eating plant-based meat. Almost three-quarters of consumers said plant-based meat needs to taste like the real thing, which has flavoring companies creating different masking ingredients and developing processes to try to impart a more neutral taste to the pea and other proteins that are used in the sector.
This research, which Rains said is starting to show promising results, is peaking the interest of several plant-based foodmakers, which don't use MSG currently.
"I think in a lot of those cases now, they're still warming up to the idea that MSG is going to be accepted by their consumer base," she said.
As MSG is becoming more accepted by consumers, incorporating it into these products may not be such a stretch. After all, Rains pointed out, a lot of plant-based companies are using glutamate-rich yeast extracts and sodium for flavoring — a combination that can create MSG compounds in food without using the actual ingredient.
What does the science say?
In spite of its reputation, most food scientists say that MSG has relatively few negative health impacts on consumers.
"To date, there is no strong medical evidence to show MSG is harmful," Shelke said in her email. "There are, however, anecdotal reports linking MSG to headaches and nausea and they are have been just that…anecdotes without medical substantiation."
Many say that the negative reputation stuck as a result of anti-Asian sentiment in the United States at the time. Ajinomoto has launched a campaign to get the term "Chinese restaurant syndrome" out of the dictionary, calling it both inaccurate and xenophobic.
But scientists have also been busy providing proof that MSG is not harmful. Numerous studies have been done during the last several decades. And while they don't show that MSG is a completely benign ingredient, they have shown many times over that it is safe for normal consumption. Also, MSG has been found to be safe by regulators in both the U.S. and Europe — with the U.S. even convening a special investigation into the ingredient in the 1990s from the Federation of American Societies for Experimental Biology.
"I think this younger generation in particular are the ones that are more receptive and more open, and are like, 'I don't understand why, you know? What was the big deal?' ...So I do think things are finally changing."
Senior director of public relations, Ajinomoto Health & Nutrition North America
"Changing something that's so deep rooted in such a visceral reaction to an ingredient takes time, and so in many ways I'm not surprised, but here we are 50 years later and are still having this conversation, even though this body of evidence is solid," Rains said. "You know, all of these regulatory bodies around the world have all independently come up with the same conclusion. But it just takes time for people to get there."
Anca Zanfirescu, an associate pharmacy professor in Bucharest, Romania, has been studying MSG since writing her doctoral dissertation on it. Her interest was sparked because there is so much controversy over the ingredient, she told Food Dive, and there have been so many studies about it through the years. She was part of a team that did a research review on MSG published last year in the Institute of Food Technologists' journal Comprehensive Reviews in Food Science and Food Safety.
While there is still research that can be done on the ingredient — previous studies haven't revealed much about the ingredient's impact on the fetuses of pregnant women, how susceptible people with pre-existing conditions like fibromyalgia are to potential negative impacts and its impacts on body mass index — Zanfirescu said consumption of normal amounts of MSG is not harmful.
"If you eat a small amount, it's not harmful because our body just breaks it down," Zanfirescu told Food Dive. "It's not a big deal if you have some noodles, ...but if you eat every day, three meals a day, you may have a problem. It's not an ingredient to run from."
So why do consumers still see MSG in such a bad light? Shelke wrote that it appears to be a sort of backlash, in which people hold firmly to a strongly negative belief — and hold on to it more tightly as others try to disprove it.
"Parallels to the persistent and ardent MSG phobia may be drawn to beliefs about vaccinations, political opinions, and climate change," she said in her email. "We can see shades of this backlash effect with dairy, eggs, red wine, caffeine, and meat…perhaps just not as deeply colored. It appears that appealing with science and sensibility to people’s misperceptions of MSG only strengthens them."
Will consumers continue to buy into it?
While many consumers have consciously avoided MSG for decades, most manufacturers haven't shied away from it.
After all, MSG has had GRAS status for years, and that's what matters most to food companies, Rains said. Of course, she said, many of the products that have traditionally included MSG don't always have the most discriminating consumers.
"I think that's why currently we see MSG mostly in foods that I would classify sort of as the 'eat in moderation' foods, because that consumer, you know, they're not really reading a label when they pick up barbecue potato chips, right?" Rains said. "They just want to enjoy that food. And so it doesn't bother them that MSG is in there."
Shelke said there are several ways that MSG can appear on an ingredients label. Manufacturers seem to be responsive to what their consumers would think about seeing it there. Some list it as monosodium glutamate. Others, she wrote, refer to it using terminology including "monosodium salt, monohydrate, monosodium glutamate monohydrate, monosodium L-glutamate monohydrate, MSG monohydrate, sodium glutamate monohydrate, UNII-W81N5U6R6U, L-Glutamic acid, monosodium salt, and monohydrate."
But as consumers are more interested in what's in their food and the science to back it up, Rains said it seems MSG may be starting to shed its past reputation. At many conferences, she's shown people a bottle of Ac'cent. They've said things like, "Oh, my grandmother used that all the time," or "We have that in our pantry at home." About 75% of them seem shocked that the seasoning inside is MSG.
Rains is hopeful that as a younger consumer population emerges, prominent chefs and scientists speak in favor of MSG and its presence is considered a valued addition to products, the ingredient's past can be put in the past.
"We track, as much as we can, consumer perception, and have been seeing this shift, this openness, to having MSG on the ingredients statement," Rains said. "... Once they understand what it is, they seem more receptive. And it does seem to skew younger. Millennials, Gen Z, they seem to be much more open to its seasoning potential.
"And as that becomes the target consumer for some of these different products, then I think the marketing departments, who maybe were the group that was saying, 'Hey, product and food scientists, you can't use this.' I think now they're saying, 'You know what, it doesn't seem to bother people as much.'"