Monosodium glutamate (MSG):

How do you feel about monosodium glutamate, also known as MSG? If you haven’t heard of it, don’t worry!
It’s not that popular anymore in the U.S., but there are still places where it’s used heavily, especially Asia and other countries in that region.
MSG isn’t all bad—in fact, there are good uses for it—but if you have sensitivities to it or simply don’t want it in your food, you should know what to look out for when dining out or eating prepared foods at home.

What is it?

MSG is a flavor enhancer that consists of salt combined with an amino acid. Monosodium glutamate is produced by fermenting corn, sugar beets or molasses using a bacterial culture.

There are claims that MSG causes allergic reactions; however no clinical evidence exists to support these claims. A study in Clinical Immunology investigated whether MSG was responsible for exacerbating asthma symptoms after exposure to fish.

The study involved participants who consumed a high-glutamate diet (including 5 grams of MSG) and those who consumed a low-glutamate diet (without any additional MSG).

In both groups there were no differences in asthma symptom ratings between pre- and post-exposure periods suggesting that glutamate was not responsible for exacerbating symptoms.

How does it affect you?

Monosodium glutamate (MSG) is a flavor enhancer added to many foods. People have long had concerns about MSG’s side effects on their health, but science has proven time and again that MSG is safe for consumption in moderation.

In fact, it’s become so ubiquitous—even in products marketed as natural—that you’d be hard-pressed to find any processed food that doesn’t contain it.

Although people with a severe sensitivity may still suffer negative side effects from consuming MSG, most everyone else can consume it without worrying about potential hazards.

Is it in your food?

Monosodium glutamate (MSG) is a commonly used flavor enhancer in prepared foods. Since it became widely available to home cooks in 1866, MSG has been vilified by some as an unhealthy additive.

As with many food myths, much of what we believe about MSG is just that—myth. And while there may be individual reactions to certain ingredients or processing methods, no credible research has shown that healthy levels of consumption can harm most people who eat them.

In fact, some research suggests that foods containing moderate amounts of naturally occurring MSG have health benefits for some people. Let’s break down what we know about this often-misunderstood ingredient and separate fact from fiction.

Symptoms you should watch out for

If you eat food containing monosodium glutamate (MSG) and start feeling symptoms of headaches, nausea or dizziness, you might need to avoid MSG.

Some people are sensitive to MSG; they will develop allergic reactions like headaches or a flushing of the face. If you think you are having an allergic reaction to something in your food that has been added during processing it is important that you seek medical advice as soon as possible.

Symptoms typically appear within hours of eating MSG-containing foods but can also be delayed for up to 48 hours after exposure. It is important not to confuse these symptoms with other conditions such as migraine headache or foodborne illness caused by Salmonella.

Allergic reactions

According to some studies, large doses of MSG may cause headaches or flushing in susceptible individuals. In lab tests, high doses of MSG also causes a reaction in rats that has been characterized as an allergic reaction.

But these experiments were done with intravenous injections at doses much higher than people typically consume. It’s unlikely that you’ll develop allergic reactions to MSG just by eating foods with it in them.

However, if you have migraines, we’d suggest avoiding foods containing high amounts of glutamate—the chemical naturally occurring in MSG (and used to make it)—just to be safe.

Who should avoid it?

MSG has long been considered bad for you, but that reputation may be unwarranted. Research suggests there isn’t a clear link between MSG and negative health effects—in fact, some experts believe MSG might actually help reduce symptoms of certain allergies. Plus, it’s not just common in Chinese food.

You’ll find it in canned vegetables like tomato soup or chicken noodle soup and packaged meals like ramen noodles. So if you want to avoid it, make sure to read labels carefully.

It’s best to limit your intake of processed foods as much as possible (for more on why, check out our guide to avoiding processed foods). And if you do eat something with MSG in it, don’t panic; chances are your body will handle it just fine.

Where can you find it?

If you’re concerned about consuming MSG, there are a few things to watch out for. It’s typically found in processed foods, but it can also be hidden under a variety of names including textured protein (or hydrolyzed vegetable protein), autolyzed yeast extract or yeast extract.

If you’re watching your sodium intake, consider that MSG has nearly 60 percent more sodium than table salt by weight.

Depending on how much you consume per day and your body type, high sodium levels can cause water retention and increased blood pressure—another reason why it may not be healthy to overdo it with processed foods. Even if you don’t react to it directly, excess sodium can lead to health problems down the road.

So, if you’re going to eat MSG-laden foods, do so in moderation. And don’t forget about other food additives and preservatives such as disodium guanylate or disodium inosinate which contain forms of glutamate; they’re sometimes added alongside MSG.

Best foods to eat if you have a sensitivity.

In addition to reducing your intake of foods with MSG in them, you should also watch out for other potential food sensitivities.

For example, someone who is sensitive to MSG might also experience negative symptoms after eating tomatoes or eggplants.

If you notice that a particular food consistently gives you a bad reaction when eaten on its own, there’s probably a good chance it contains ingredients that are giving you trouble.

Whether or not these foods contain any substances known to cause allergic reactions is another story—that would be something for your doctor to determine.

Regardless, if you have a sensitivity to one substance (such as MSG), it’s likely you have some level of sensitivity to others as well.