What is MSG?

MSG is a popular flavor enhancer derived from L-glutamic acid, a naturally occurring amino acid that's necessary for the creation of proteins.

Aside from being used as a food additive, MSG occurs naturally in certain foods, including tomatoes and cheeses.

It was first identified as a flavor enhancer by Japanese researchers in 1908 and has since become one of the most widely used additives in food production.

Today, it can be found in a number of processed products, from fast food to canned soups.

MSG boosts the flavor of foods by stimulating taste receptors and has been shown in research studies to increase the acceptance of particular flavors. Adding MSG to foods results in an umami taste, which is characterized as savory and meaty.

This popular additive has been deemed GRAS by the FDA, though some experts argue that it can have potentially dangerous side effects, particularly when consumed on a long-term basis.

The FDA mandates that MSG must be labeled by its usual name of monosodium glutamate when used as an ingredient in food. Foods that naturally contain MSG, such as tomato products, protein isolates, and cheeses, aren't required to list MSG as an ingredient.

In other countries, MSG is classified as a food additive and may be listed by the E-number E621.

Here are 8 foods that commonly contain MSG.

1. Fast Food

One of the best-known sources of MSG is fast food, particularly Chinese food.

In fact, Chinese restaurant syndrome is a condition characterized by symptoms including headache, hives, swelling of the throat, itching, and belly pain experienced by some people shortly after consuming MSG-laden Chinese food.

Although many Chinese restaurants have stopped using MSG as an ingredient, others continue to add it to a number of popular dishes, including fried rice.

MSG is also used by franchises like Kentucky Fried Chicken and Chick-fil-A to enhance the flavor of foods.

For example, Chick-fil-A's Chicken Sandwich and Kentucky Fried Chicken's Extra Crispy Chicken Breast are just some of the menu items that contain MSG.

2. Chips and Snack Foods

Many manufacturers use MSG to boost the savory flavor of chips.

Consumer favorites like Doritos and Pringles are just some of the chip products that contain MSG.

Aside from being added to potato chips, corn chips, and snack mixes, MSG can be found in a number of other snack foods, so it's best to read the label if you want to avoid consuming this additive.

3. Seasoning Blends 

Seasoning blends are used to give a salty, savory taste to dishes like stews, tacos, and stir-fries.

MSG is used in many seasoning blends to intensify taste and boost the umami flavor cheaply without adding extra salt.

In fact, MSG is used in the production of low sodium items to increase flavor without the addition of salt. MSG can be found in many low sodium flavoring products, including seasoning blends and bouillon cubes.

Additionally, MSG is added to some meat, poultry, and fish rubs and seasonings to enhance the palatability of foods.

4. Frozen Meals 

Although frozen meals can be a convenient and cheap way to put food on the table, they often contain a host of unhealthy and potentially problematic ingredients, including MSG.

Many companies that make frozen dinners add MSG to their products to improve the savory flavor of the meal.

Other frozen products that often contain MSG include frozen pizzas, mac and cheese, and frozen breakfast meals.

5. Soups

Canned soups and soup mixes often have MSG added to them to intensify the savory flavor that consumers crave.

Perhaps the most popular soup product that contains this controversial additive is Campbell's chicken noodle soup.

Many other soup products, including canned soups, dried soup mixes, and bouillon seasonings, can contain MSG, making it important to check individual product labels.

6. Processed Meats  

Processed meats like hot dogs, lunch meats, beef jerky, sausages, smoked meats, pepperoni, and meat snack sticks can contain MSG.

Aside from being used to enhance taste, MSG is added to meat products like sausage to reduce the sodium content without changing the flavor.

One study found that replacing sodium with MSG in pork patties enhanced the salty flavor and acceptability of the product without negatively affecting taste.

7. Condiments 

Condiments like salad dressing, mayonnaise, ketchup, barbecue sauce, and soy sauce often contain added MSG.

In addition to MSG, many condiments are packed with unhealthy additives like added sugars, artificial colorings, and preservatives, so it's best to purchase products that are made with limited, whole food ingredients whenever possible.

If you're concerned about using MSG-containing condiments, consider making your own so that you have complete control over what you're consuming. For starters, you can try out these delicious and healthy salad dressing recipes.

8. Instant Noodle Products

A staple for college students around the world, instant noodles provide a quick, filling meal for those on a budget.

However, many manufacturers use MSG to boost the savory flavor of instant noodle products. Plus, instant noodles are typically made from unhealthy ingredients and are loaded with added salt, refined carbs, and preservatives that can harm your health.

Instant noodle consumption has been associated with increased heart disease risk factors, including elevated blood sugar, cholesterol, triglyceride, and blood pressure levels.

Is MSG Harmful?

While research is far from conclusive, some studies have suggested that consuming MSG may lead to negative health outcomes.

For example, MSG consumption has been linked to obesity, liver damage, blood sugar fluctuations, elevated heart disease risk factors, behavioral problems, nerve damage, and increased inflammation in animal studies.

Some human research has demonstrated that consuming MSG may promote weight gain and increase hunger, food intake, and your risk of metabolic syndrome, a group of symptoms that raises your risk of chronic conditions like heart disease and diabetes.

For example, a study in 349 adults found that those who consumed the most MSG were much more likely to have metabolic syndrome than those who consumed the least, and that every 1 gram increase of MSG per day significantly increased the chances of being overweight.

However, larger, well-designed studies are needed to confirm this potential link.

There's also some evidence that MSG increases hunger and may lead you to eat more at meals. However, current research suggests a more complex relationship between MSG and appetite, with some studies finding that MSG may even decrease intake at meals.

Although research is mixed on how MSG may affect overall health, it's clear that consuming high doses of 3 grams or higher of MSG per day is likely to lead to adverse side effects, including headache and increased blood pressure.

For reference, it's estimated that the average consumption of MSG in the United States and the United Kingdom is around 0.55 grams per day, while intake of MSG in Asian countries is around 1.2–1.7 grams per day.

Although it's possible, consuming 3 grams of MSG or more per day is unlikely when eating normal portion sizes.

However, certain individuals who have a sensitivity to MSG may experience side effects like hives, swelling of the throat, headache, and fatigue after consuming smaller amounts, depending on individual tolerance.

Still, a review of 40 studies found that, overall, studies that have linked MSG with adverse health effects are of poor quality and have methodological flaws, and that strong clinical evidence of MSG hypersensitivity is lacking, highlighting a need for future research.

While evidence of MSG sensitivity is lacking, many people report that consuming this additive leads to adverse side effects.

If you think you may have a sensitivity to MSG, it's best to avoid the products listed on this page and always check labels for added MSG.

Furthermore, even though the safety of MSG is debated, it's clear that foods that commonly contain MSG, like chips, frozen meals, fast food, instant noodles, and processed meats, aren't good for overall health.

Therefore, cutting out MSG-laden products will likely benefit you in the long run — even if you aren't sensitive to MSG.

Summary

Some studies have associated MSG with negative health outcomes, including obesity and metabolic syndrome. However, more research is needed to substantiate these findings.

The Bottom Line

MSG is a controversial food additive that's found in a wide variety of products. It's commonly added to chips, frozen dinners, fast food, instant noodles, and many other processed foods to enhance flavor.

Although some studies have linked MSG consumption with negative health outcomes, more research is needed to fully understand the potential effects that consuming MSG may have on both short- and long-term health.

If you feel that you're sensitive to MSG, it's best to avoid products that contain it. Be sure to always read food labels to ensure your items are free of MSG.