In 1908, Japanese scientist Kikunae Ikeda returned from Germany, where he had developed a fondness for the savory flavors of local dishes. He discovered a similar taste sensation, now referred to as umami, while enjoying a bowl of kombu seaweed soup. Curious about the source of this flavor, he boiled the seaweed to isolate its essence. This led to the creation of an ingredient known for enhancing the complex umami flavor in various dishes, which subsequently became a staple in processed foods worldwide. However, this ingredient—monosodium glutamate (MSG)—also found itself on the list of substances many consumers sought to avoid.
The negative perception of MSG largely stemmed from a 1968 letter to the editor of the New England Journal of Medicine by Dr. Robert Ho Man Kwok, a physician who reported experiencing headaches, dizziness, and general malaise after dining at Chinese restaurants. He attributed these symptoms to MSG, which sparked a consumer backlash against the ingredient. Despite the fact that MSG has consistently been deemed safe by the FDA and that Dr. Kwok’s letter lacked scientific backing, the stigma persisted. Moreover, the only research linking adverse effects to MSG involved administering extremely high doses to rodents and primates, while MSG had been used safely in American kitchens for nearly six decades prior, with few reports of negative side effects.
Over the years, numerous scientific studies have aimed to validate the safety of MSG. Kantha Shelke, a food scientist and founder of the consulting firm Corvus Blue, noted in an email to Food Dive that the unjust stigmatization of MSG has caused “unnecessary anxiety” among consumers. She observed that people often distrust unfamiliar ingredients, allowing peer influence and vocal activists to shape their perceptions more than scientific evidence.
What many consumers may not realize is that MSG has been a common ingredient in countless products for years. According to FDA statistics, the average American consumes about half a gram of MSG daily, often found in snacks, ranch dressing, condiments, and soups. Ac’cent seasoning consists of 100% MSG, and Ajinomoto, the company founded by Ikeda in 1909, controls about 70% of the U.S. MSG market, with sales growing by approximately 5% annually.
As younger generations show a greater interest in authentic, flavorful cuisines and transparency about food ingredients, MSG is experiencing a revival. During the competitive “chicken sandwich wars” among fast-food chains, McDonald’s, Popeyes, and Chick-fil-A all acknowledged including MSG in their flagship offerings. Despite media scrutiny of this ingredient, consumer demand remains strong. Tia Rains, senior director of public relations for Ajinomoto Health & Nutrition North America, suggested that millennials and Gen Z are leading this shift in perception.
“They seem more open to facts and less influenced by the stigma,” Rains explained. “They didn’t grow up with the same ‘No MSG’ warnings, and they’re curious about the science behind food ingredients.” While MSG is often assumed to be a laboratory-created additive, Rains clarified that it is a naturally occurring compound. The umami taste Ikeda discovered in kombu is attributed to glutamate, one of the 20 amino acids essential for all proteins. After experimenting with various salts, he found that sodium produced the best seasoning characteristics.
Ajinomoto produces MSG in a facility in Eddyville, Iowa, using a fermentation process that transforms sugar into glutamate, which is then combined with sodium to create MSG crystals. The leftover material, known as broth, is repurposed as animal feed in the U.S., while similar processes elsewhere convert it into fertilizer. This demonstrates that MSG aligns with two significant food trends: clean labeling and sustainability.
Rains emphasized that MSG is a versatile seasoning that enhances umami, the fifth taste sensation. Although often associated with Asian cuisine—possibly due to Ikeda’s heritage or the kombu used in his discovery—the glutamate responsible for this flavor is prevalent in many global foods. Ikeda initially noted umami in German cuisine, and traditional foods like sauerkraut are rich in glutamate, as are Parmesan cheese and various mushrooms.
MSG is not only a flavor enhancer but can also serve as a sodium-reducing agent. Research supported by Ajinomoto published in the journal Nutrients last year indicated that MSG could lower the average American’s sodium intake by around 8%. Even though MSG contains sodium, it has only about one-third the sodium content of table salt. The broader adoption of MSG could assist food manufacturers in meeting the FDA’s voluntary sodium reduction targets, aimed at decreasing the average American’s sodium consumption by one-third by 2025.
Rains noted that there is ongoing research exploring MSG’s potential as a flavoring for plant-based meats, addressing the primary consumer concern regarding the taste of these products. Many consumers—three-quarters, according to a white paper from Kerry—believe that plant-based meats must taste like their traditional counterparts. This has prompted flavoring companies to experiment with various ingredients to enhance the taste of plant proteins.
As attitudes toward MSG shift, its inclusion in plant-based products may become more acceptable. Many plant-based companies currently utilize glutamate-rich yeast extracts and sodium for flavoring, which can naturally create MSG-like compounds without directly using MSG. Despite its controversial reputation, most food scientists maintain that MSG poses few negative health risks.
“To date, there is no strong medical evidence to suggest MSG is harmful,” Shelke affirmed. While anecdotal reports exist linking MSG to headaches and nausea, they remain unsubstantiated by medical research. The negative perception of MSG is believed to have roots in anti-Asian sentiment prevalent in the U.S. during the time of its rise. Ajinomoto has launched initiatives to eliminate the term “Chinese restaurant syndrome” from common usage, deeming it both inaccurate and discriminatory.
Scientists have consistently provided evidence supporting MSG’s safety. Numerous studies conducted over the past few decades have repeatedly confirmed that MSG is safe for regular consumption. Regulatory agencies in both the U.S. and Europe have recognized MSG as safe, with the U.S. even conducting a special investigation into the ingredient in the 1990s.
“Changing deeply ingrained perceptions about an ingredient takes time,” Rains remarked. “It’s surprising that we are still discussing this 50 years later, despite a robust body of evidence affirming MSG’s safety.” Anca Zanfirescu, an associate pharmacy professor in Bucharest, Romania, who has extensively researched MSG, shared similar sentiments. She noted that while there are still areas for further study—such as its effects on pregnant women and individuals with certain pre-existing conditions—normal consumption of MSG is not harmful.
“Moderate intake poses no risk, as the body effectively metabolizes it,” Zanfirescu explained. “Having some in your noodles is fine; however, excessive daily consumption could be problematic.”
So why does MSG continue to carry a negative connotation? Shelke suggested that this reflects a broader societal backlash against unfamiliar ingredients, wherein individuals cling to negative beliefs even as evidence mounts against them. “This phenomenon can be seen in various areas, from vaccinations to climate change,” she noted.
Despite consumer hesitance toward MSG, manufacturers have generally remained unperturbed. The ingredient has held Generally Recognized As Safe (GRAS) status for years, which is crucial for food companies. Many products containing MSG are often not scrutinized by health-conscious consumers.
“I believe that’s why MSG remains common in foods classified as ‘eat in moderation’ options,” Rains stated. “Consumers of these products may not read labels closely; they are simply seeking enjoyment.”
Shelke noted that MSG can appear on ingredient labels in various forms, with manufacturers adapting terminology based on consumer preferences. Some label it as monosodium glutamate, while others use terms like “monosodium salt” or “sodium glutamate monohydrate.” However, as consumer interest in ingredient transparency grows, it seems that MSG is beginning to overcome its historical stigma. At various conferences, Rains has shown attendees a bottle of Ac’cent, revealing that many are surprised to learn it contains MSG.
“As younger consumers emerge, and as chefs and scientists advocate for MSG, we can hope to put its past behind us,” Rains expressed. “We are tracking consumer perceptions and are witnessing a shift toward acceptance of MSG as a legitimate ingredient.”
With a new generation of consumers open to understanding the science behind MSG, it may soon be recognized as a valuable addition to many products.