In 32 years of clinical practice, I’ve taken dietary histories on thousands of adults and children. At some point, nearly all Americans have eaten Chinese food, either by going to a restaurant or getting take-out. If I ask them if they avoid monosodium glutamate – what they know as MSG – those that have heard of it will almost always say they avoid it. My patients who would be considered “foodies” almost universally avoid MSG in their food. Or do they? More about that later.
Sensitivity to MSG, commonly known as “Chinese restaurant syndrome” started not with any evidence, but with an article written by a physician in the New England Journal of Medicine in 1968, that described his own symptoms: a numbness at the back of the neck and a feeling of pressure in his upper chest muscles and face. As he’d recently eaten in a Chinese restaurant, he coined this feeling “Chinese restaurant syndrome” (CRS). All of a sudden, people started claiming they’d suffered from CRS and as public fear spread, Chinese restaurants began omitting it in the foods they prepared.
But did anyone look for the evidence? Later on, researchers who did double-blind, placebo-controlled studies, considered the gold-standard in research methodology, were never been able to replicate CRS. One such well-respected study that tested people who identified themselves as sensitive to MSG, found no significant differences in the prevalence of responses between groups taking the placebo or the MSG. (And if you were wondering about the title of this blog, this is the connection: the placebo effect among those who believe they have a particular sensitivity is a very powerful thing. That’s why it’s so important to conduct studies in a blinded manner. It’s the only way to determine if the sensitivity is real.)
A larger review of the research about purported sensitivity to MSG found some sensitivity when extremely large doses of MSG were given but even then there was no consistency. Researchers found no reactions to MSG when it was given with food, which is how people would typically have MSG.
Why would people? All the attention on MSG may have something to do with why people think they have a sensitivity to it but really don’t. Research has found that people with “unconfirmed” reactions to foods were “influenced by the popular news media.”
If you know a little about glutamate, the lack of negative results in humans won’t surprise you. Here’s the boil-down:
- Glutamate is an amino acid, a protein that your body makes in huge amounts – it’s the most prevalent amino acid in the body.
- The vast majority of glutamate resides in your gut and never gets absorbed into the bloodstream.
- If you’ve heard chefs speak about “umami” or the “fifth taste”, they’re talking about glutamate, and we have lots of glutamate receptors on our tongues.
- Most people eat about 10 to 20 grams of glutamate every day, but only about a tenth of that is eaten as a seasoning or condiment, even in cuisines that use a lot of MSG.
- Glutamate is found in two forms, bound glutamate and free glutamate. The bound glutamate is part of larger proteins. The free glutamate is what influences taste.
- Glutamate is naturally present in many foods – and many foods we like a lot, like tomatoes, mushrooms, and parmesan cheese. Italian food couldn’t exist without glutamate!
If people feel they’re sensitive to MSG, then they’d also have to be sensitive to many foods they’re probably already eating. Indeed, an Italian dish with tomatoes, mushrooms, and parmesan cheese is virtually a glutamate bomb. If they are not sensitive to these foods, glutamate can most likely be ruled out as the culprit.
In addition, the International Food Information Council published a great consumer-friendly review of the research on MSG that explains the safety of MSG.
Advantages of MSG?
Don’t laugh, there are many. MSG gives food more intense flavor, that’s the umami. It also has sodium but way less sodium than regular salt, or sodium chloride. A 2016 study found that about a third of the sodium in soup could be reduced simply by swapping out some of the regular salt for MSG, and with the same level of acceptance.
Glutamate is safe, MSG is safe. Numerous global health authorities have clear positions outlining the safety of glutamate. Your body makes glutamate and it’s so naturally prevalent in our food supply that you couldn’t avoid it if you tried and you couldn’t survive if you did avoid it.
There’s no evidence MSG causes headaches, CRS, or any other health maladies. But it can truly enhance the taste of our food, and it enhances the taste of many healthful foods. World-renowned health organizations like the National Academy of Sciences, the European Community’s Scientific Committee for Food, and the American Medical Association Council on Scientific Affairs have all confirmed the safety of MSG as it is present in our diets. I make recommendations to my patients that are evidence-based because it’s the ethical way to practice nutrition, and I can feel fully confident in the evidence on the safety of MSG.