Is MSG Bad For You?

Wondering if MSG is safe and whether you should avoid it? Get the facts on how MSG got a bad reputation–and where things stand now.

This post is NOT sponsored in any way. I originally published a shorter version of this post on WebMD.

Monosodium glutamate (MSG) is popularly known as “that stuff in Chinese food that gives you a headache”. But what’s the truth?

MSG: The Backstory

MSG is a seasoning made from sodium and glutamate, an amino acid that’s found naturally in the body and in some foods like tomatoes, soy sauce, and aged cheeses. Glutamate was discovered as a flavor enhancer in 1908 by a Japanese professor, who pinpointed glutamate as the substance that gave his favorite seaweed broth its rich, savory taste. Glutamate is unique because it hits the fabled “fifth taste” called umami (Japanese for “delicious”), a savory and meaty flavor. The professor filed for a patent to produce MSG, and it became widely used to season food.

What are MSG concerns?

In 1968, a letter appeared in The New England Journal of Medicine from a doctor claiming he experienced heart palpitations and flushing after eating in Chinese restaurants. He chalked it up to MSG in the food, and the editors of the journal dubbed it “Chinese Restaurant Syndrome”.

Anecdotal reports started swirling about MSG and the symptoms it supposedly triggered, from headaches and nausea to tightness in the chest. When I asked about MSG on my Real Mom Facebook page, some people mentioned MSG side effects like a racing heart, insomnia, and swelling of the hands and feet.

MSG: The Latest

Is MSG safe?

Though there were plenty of anecdotal reports about MSG, scientific evidence was thin. So in the 1990s, the FDA asked an independent scientific group to investigate. The group concluded that MSG is safe, though they said some sensitive people might get short-term symptoms like headache or drowsiness if they consume 3 grams or more of MSG (a typical serving of MSG in food is less than .5 grams).

The FDA classifies MSG as “generally recognized as safe”, the same designation they give ingredients like sugar and baking soda (but, to be fair, also the same designation they give additives that haven’t been tested by the FDA for safety). The FDA says the body metabolizes MSG the same way it does the natural glutamate found in foods like tomatoes and cheese. 

Does MSG cause headaches?

A 2016 analysis of studies published in the Journal of Headache Pain concluded that there’s no proof of a cause-and-effect relationship between MSG and headaches. It’s also worth noting that in 2018, the International Headache Society removed MSG from its list of headache triggers.

Does MSG cause weight gain?

MSG has been studied for a possible connection with weight gain. One explanation is that MSG makes food taste better–so you may eat more of it. Another is that the additive may disrupt hunger-fullness hormones. In one study of more than 10,000 Chinese adults published in the American Journal of Clinical Nutrition, those who ate the most MSG were 33 percent more likely to be overweight after five years compared to those who ate the least amount. But other research doesn’t show this effect–or shows the opposite.

MSG: What You Should Do

If you believe you have a sensitivity to MSG, by all means continue to avoid it. Although there’s no scientific evidence of a sensitivity, every person is different. Just because science doesn’t prove something doesn’t mean it’s not happening to you. 

Where is MSG in food?

If you’re avoiding MSG, how do you know if a food contains it? According to the FDA, food with added MSG must list it in the ingredient panel as “monosodium glutamate”.  You may find added MSG in foods like:

• Chinese food
• canned soup
• frozen foods
• fast food
• packaged snacks

MSG occurs naturally in certain food ingredients too, including:

• hydrolyzed vegetable protein
• autolyzed yeast
• hydrolyzed yeast
• yeast extract
• soy extracts
• protein isolate

If you’re staying away from MSG, you should avoid products with those ingredients too. (You’ll see those ingredients named on the ingredient list, but manufacturers aren’t required to state that the product contains MSG unless it also contains the monosodium glutamate seasoning specifically.) If you eat a diet that’s overall low in highly processed foods, you’ll naturally consume fewer of those ingredients.

You can also look for the package claims “No MSG” or “No added MSG”. Any food that contains MSG either as monosodium glutamate or via one of the ingredients listed above cannot make those claims. The FDA also says MSG is not allowed be listed as simply “spices and flavoring” in the ingredient list.

How to use MSG

There are upsides to using MSG if you don’t think you are sensitive to it. MSG increases flavor and adds depth–but it has two-thirds less sodium that regular table salt. And you don’t need very much to boost flavor. According to Ajinomoto, which makes MSG seasoning, you only need a half-teaspoon to enhance the flavor of a pound of meat or up to six servings of veggies or soup.

If you want to try the seasoning for yourself, you can find it in the spice aisle under names like Accent. Sprinkle a little bit into a casserole or batch of soup and see if you like the way it makes your food taste–and the way it makes you feel.

In my opinion, it’s much better to know the facts and try things firsthand than to rely on rumor.