Is MSG bad for you? How the ingredient got a bad reputation—and why it’s changing

MSG’s reputation has been on the mend for years. Once blamed for dubious health concerns like headaches, numbness, and chest pains, the ingredient now appears in cocktails, cookies, and influencer pantry tours with growing pride.

But MSG’s cultural redemption hasn’t happened in a vacuum. Ajinomoto—the world’s largest producer of monosodium glutamate, or MSG—has played a quiet but consistent role in reshaping how we think about the additive. And a wave of Asian American chefs and creators, including David Chang in a 2012 TED Talk, have been reclaiming it over the last decade, pushing back against decades of xenophobia and misinformation.

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What is MSG?

First isolated from kombu in 1908 by Japanese chemist Kikunae Ikeda, monosodium glutamate was hailed as a scientific breakthrough—a crystalline distillation of umami. A year later, Ikeda helped establish Ajinomoto to manufacture and distribute the seasoning commercially.

Marketed as a kind of culinary enlightenment, the ingredient’s popularity spread quickly across East and Southeast Asia. Restaurants stocked it tableside; ads described it as refined, nutritious, and essential for the modern household.

In the United States, MSG gained traction after World War II, when returning American soldiers remarked that Japanese rations tasted better than their own—a difference attributed, in part, to the use of MSG. The seasoning caught the attention of food scientists and entered American kitchens in the late 1940s.

From miracle powder to cultural scapegoat

By the 1950s, MSG was a staple of industrial kitchens and processed foods—from canned soups to frozen dinners—embedding itself in the architecture of quick and easy American food.

Then came the backlash. In 1968, a Chinese American physician named Robert Ho Man Kwok wrote a letter to the New England Journal of Medicine, describing symptoms—numbness, weakness, palpitations—he occasionally experienced after eating at Chinese restaurants. He suggested MSG as a possible cause, among other ingredients like salt and soy sauce. Readers wrote in claiming similar experiences, and soon, “Chinese Restaurant Syndrome” entered the cultural lexicon.

A year later, a paper in Science authored by a neurologist gave the MSG theory scientific veneer, despite what modern researchers have described as questionable, anecdotal evidence. MSG quickly became a scapegoat for anxieties around Chinese food. Restaurants began displaying “No MSG” signs to reassure diners, and at one point, the U.S. government considered restrictions on MSG.

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Debunking scientific myths about MSG

Yet decades of scientific studies have failed to find a consistent link between MSG and these alleged symptoms. Major health organizations, including the U.S. Food and Drug Administration, World Health Organization, and European Food Safety Authority, have concluded that MSG does not pose a health risk when consumed at typical dietary levels. A 1995 FDA analysis stated that there is “an absence of data to support a neurotoxic effect from MSG at levels required to produce a flavor-enhancing effect.”

“Every major public health organization has reviewed the evidence,” says Tia Rains, vice president of science at Ajinomoto. “When it’s used as seasoning in food, it is not harmful to the public,” though it can pose risks if consumed in large amounts.

Over the past five years, Ajinomoto has sponsored educational content, partnered with influencers, and pushed to correct long-standing myths around MSG’s safety.

They’re also actively pushing back against critics. In a 2022 advertising dispute in Brazil, Ajinomoto filed a complaint with the country’s advertising self-regulatory body, the National Council for Advertising Self-Regulation (CONAR), alleging that a Burger King ad campaign misled consumers by unfairly implying that MSG was harmful. Ajinomoto initially won, arguing the ads unfairly targeted MSG, but the decision was overturned when CONAR ruled that the negative implications about MSG were subjective and fell within the bounds of commercial free speech.

MSG and the discovery of umami

In fact, the groundwork for MSG’s rehabilitation began well before the glossy explainers and branded partnerships; it started in the 1980s with a scientific campaign to legitimize umami. At the helm was Kumiko Ninomiya, a biochemist who spent 40 years in Ajinomoto’s global communications department and became known as the “Umami Mama.” She set out to prove that umami wasn’t just a flavor, but the fifth basic taste with its own receptors, putting it on equal footing with sweet, salty, sour, and bitter.

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With Ninomiya leading the charge, Ajinomoto helped establish the Umami Information Center, where they organized international symposiums bringing together scientists to explore the sensory basis of umami.

The breakthrough came in the early 2000s, when a group of independent American researchers identified a taste receptor specifically for glutamate, cementing umami’s status alongside the other four basic tastes.

That finding helped reframe MSG—not just as an artificial additive, but as a purified form of something elemental.

Ajinomoto played a central role in promoting those findings. “When scientists discovered the glutamate receptor, that news spread around the world,” says Ninomiya. “We decided to share that information more widely to chefs and nutritionists.”

Rediscovering the flavor of MSG

Today, that scientific validation underpins a broader cultural shift—one shaped by genuine enthusiasm, but also by a corporate narrative that has quietly blurred into cultural reclamation.

When identity, science, and branding align, it can be hard to tell who’s leading the conversation. Chefs go out of their way to praise MSG’s transformative effect on food; content creators flaunt it in videos; dietitians even recommend it to clients seeking more flavor with less sodium.

“I focus on helping people have an enjoyable relationship with healthy food,” says Kathleen Benson, a registered dietitian in El Paso, Texas. “Umami is key for that satisfaction, and MSG is one of the tools we can use to enhance it.”

For Calvin Eng, chef-owner of Bonnie’s, a Cantonese American restaurant in Brooklyn, MSG isn’t just an enhancer—it’s a fixture. “Like salt and sugar, it’s something I always have on the counter,” he says.

Though Eng grew up with chicken powder, which contains MSG, he didn’t start cooking with pure MSG until working in restaurants. Now, he uses it across the board: fries, desserts, even martinis. “When you have sweet, savory, umami—it just makes things more special and unique.”

His debut cookbook, Salt Sugar MSG, puts the ingredient front and center. “I was afraid my publisher would say it’s not marketable,” he recalls, about including MSG in the title. “But they were cool with it, and it stuck.”

For some, embracing MSG also means unlearning inherited stigma. “I grew up thinking MSG was bad for you,” says Jenn Ko, co-founder of Dime, a playful MSG brand aimed at making the ingredient feel more approachable. “My family always looked for restaurants that advertised ‘No MSG.’” Her turning point came when she saw a friend buying MSG at the market. “I started digging into the history—how it was vilified, how that one letter started it all.”

Ko, Eng, and Lieu are part of a broader wave of Asian Americans embracing MSG—not just as seasoning, but as a proud marker of cultural identity. In 2024, Lieu and Eng signed an open letter written by Ajinomoto urging the New England Journal of Medicine to revisit the term “Chinese Restaurant Syndrome” and its role in decades of racialized fear. The journal never responded.

For Lieu, much of the stigma around MSG comes down to perception. “MSG is just three letters, so people assume it’s some scary chemical,” she says. “But if you think about it, all food is made of chemicals. Let’s stop with the racist mentality of treating it like a toxin.”