Is MSG Bad for You? What You Need to Know

MSG is short for monosodium glutamate. It is the sodium salt of an amino acid called glutamic acid which is naturally present in our bodies. This naturally occurring substance is also used as a food additive and flavor enhancer to give foods a specific hearty, savory flavor called “umami, ” a Japanese word that is generally translated to “deliciousness.”

According to the U.S. Food and Drug Administration (FDA), MSG consumption is safe in moderation, but high doses may lead to potential negative health effects, including effects on the heart, muscles, nerves, and gastrointestinal tract.

History of Monosodium Glutamate (MSG)

Discovery

Monosodium glutamate (MSG) was discovered by a Japanese professor of chemistry, Kikunae Ikeda. He noticed that his broth tasted better than usual and realized it was due to the addition of kelp (seaweed). This led him to study the chemical structure of kelp and ultimately to discover that the savory taste was due to a nonessential amino acid called L-glutamic acid (glutamate). He created its sodium salt for stability, and this came to be known as monosodium glutamate or MSG. Professor Ikeda patented the commercial production of MSG in the early 20th century.

Current Use of MSG

Today, MSG is a popular food additive. It is made by fermenting sugar cane, molasses, starch, and sugar beets. MSG is widely used worldwide as a seasoning and flavor enhancer. MSG itself does not have any taste or odor. But when it is added to foods, it brings out a special meaty, brothy, or hearty “umami” taste. The umami flavor is named after the Japanese word for delicious “umai.” Food science experts say when you eat MSG, saliva breaks apart the sodium and glutamate, and the free glutamate activates umami taste receptors.

How Is MSG Used In Foods?

As mentioned, glutamic acid occurs naturally in the body. Its sodium salt, monosodium glutamate, or MSG, naturally occurs in some foods like tomatoes and certain cheeses. MSG is also a common food ingredient that is added to enhance food taste.

Is MSG Really Unhealthy?

Common Myths and Truths About Consuming MSG

Myth: MSG is not natural.

Fact: MSG is the purified sodium salt of one of the naturally occurring amino acids called glutamic acid. While the combination of sodium and glutamate is not found in nature, the individual ingredients, sodium and glutamate, occur naturally in abundance.

Myth: Our bodies cannot process MSG.

Fact: The glutamate in MSG is chemically identical to the glutamate that occurs naturally in food. Our bodies metabolize glutamate from both sources in the same way. The average adult consumes approximately 13 grams of dietary glutamate each day from natural food sources. In contrast, the average intake of MSG added to food to enhance flavor is estimated to be about 0.5 grams per day.

Myth: MSG is only used in Asian cooking.

Fact: Asian cuisine, specifically Chinese food, is best known for using MSG, but other cultures maximize umami flavors in other ways. For example, American cuisine uses cheese to enhance umami flavors. Italian cuisine uses tomatoes, parmesan cheese, and aged meats like prosciutto. Australian cuisine includes these savory flavors through vegemite and marmite. Not to mention, canned food like chicken noodle soups also contain MSG.

Myth: MSG is dangerous for children.

Fact: MSG is safe for children. Children metabolize glutamate in the same way as adults. In fact, there is 10 times more glutamate in human breast milk compared to cow’s milk.

Scientific Research Findings

MSG gets a bad rap because some studies have found that it can potentially have negative effects on many organ systems in the body. However, many of these studies were done in lab animals. Also, human studies on MSG have assumed extremely high doses through intravenous, intraperitoneal, or subcutaneous routes of administration. Therefore, these studies may not be relevant to the health effects of MSG exposure through dietary intake, which is several-fold less and occurs through ingestion.

Health Organizations' Stance on MSG

Health authorities, including the US Food and Drug Administration (FDA), the World Health Organization (Joint FAO/WHO Expert Committee on Food Additives or JECFA), and the European Food Safety Association (EFSA) consider MSG to be a substance generally recognized as safe (GRAS). Food additives are included on the GRAS list if they have been widely used in food for decades and if their safety has been confirmed by scientific toxicological reports at the usual levels of dietary intake.

What Does MSG Do To The Human Body?

Potential Adverse Reactions

More research is needed to understand what MSG does to the human body. Some of the health effects that have been attributed to MSG include:

Increased body mass index (BMI) and weight gain.
Raised cholesterol levels, blood glucose levels, and blood pressure.
Growth of certain cancer cells.
Toxic effects on the heart, liver, brain function, reproductive organs, and immune system.
Adverse effects such as headaches, nausea, diarrhea, irritable bowel syndrome (IBS), breathing difficulties in people with asthma, and panic attacks.

Symptoms and Signs of MSG Sensitivity

MSG sensitivity, also called the Chinese restaurant syndrome (CRS) or MSG symptom complex (MSC), incriminates MSG as the main culprit for a set of symptoms including headache, weakness, dizziness, flushing, difficulty breathing, muscle tightness, numbness, and fainting. When present, these symptoms are typically mild and go away in a short time.

A study done by the FDA found no evidence that MSG in food causes MSG symptom complex. They did find that people who consume 3 grams or more of MSG alone (without food) can have minor reactions. The average amount of MSG in a typical serving of MSG-containing foods is less than 0.5 grams.

Who Is At Increased Risk?

Less than 1% of the general population is estimated to have an MSG-sensitivity. But in people who are MSG-sensitive, intake of this flavor enhancer can cause mild to severe symptoms starting 1-2 hours after ingestion.

It’s worth noting that researchers in pharmaceutical sciences say MSG sensitivity is self-reported, and a placebo effect may be at play. Meaning during double-blind trials, people reported experiencing symptoms when they were given foods containing a placebo (an inactive substance) because they thought they had consumed MSG. Additionally, the effects of other food additives cannot be ruled out in causing these symptoms.

What Happens If I Eat MSG Every Day?

Is It Safe to Consume MSG Every Day?

Yes, it is safe to consume MSG every day. The FDA has classified MSG as a food additive that is generally recognized as safe (GRAS).

How Much MSG Per Day Is Safe?

A review by the European Food Safety Authority (EFSA) in 2017 recommended an acceptable daily intake (ADI) for MSG of 30 mg per kilogram of body weight per day, which is more than most people consume.

Long-Term Effects of Daily MSG Consumption

Research has not found any long-term health effects from consuming moderate amounts of MSG.

Note: MSG can help in reducing sodium intake as it enhances food flavor but only contains one-third the amount of sodium as table salt.

How to Identify MSG in Foods

Foods Most Likely to Contain MSG

MSG is found in common foods like canned vegetables, soups, salad dressings, barbecue sauce, seasoning blends, potato chips, deli meats, fast food, frozen meals, fried chicken, processed foods, and many other foods.

MSG on Food Labels

The FDA requires all packaged foods containing added MSG to list it on the ingredient panel as monosodium glutamate.

However, the agency does not require foods that naturally contain MSG to indicate this on the label. As noted above, MSG is naturally present in foods such as tomatoes and cheeses and in food ingredients such as hydrolyzed yeast, autolyzed yeast, yeast extract, hydrolyzed vegetable protein, soy extracts, and protein isolate.

Notably, foods containing MSG or containing ingredients that naturally contain MSG cannot say “No added MSG” or “No MSG” on the packaging. The FDA also does not allow MSG to be listed as a “flavoring” or “spice.”

MSG Alternatives in Cooking

If you want to avoid MSG without sacrificing flavor, experts in clinical nutrition recommend eating the following foods and adding the following ingredients to your meals: