MSG Dangers and Allergies: Myths Debunked

Medically Reviewed By Jillian Kubala, MS, RD

Many myths surround monosodium L-glutamate (MSG) in foods. Despite the fact that recent studies have proven the safety of MSG, many people believe that this food additive can cause serious health conditions, such as cancer, brain damage, and asthma. If you experience severe symptoms after eating a meal cooked with MSG, your symptoms are likely not the result of MSG. Rather, they may be due to an underlying health issue or another factor, such as an allergy to the food you ate.

This article debunks different MSG myths by reviewing what studies say about this food ingredient. It also explains what MSG is and discusses how it is produced, its safety levels, and some alternatives. 

What is MSG? 

there is a model of a burger
Yaroslav Danylchenko/Stocksy United

MSG is one of the most common food ingredients Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source used in commercial meals. It is the sodium salt of glutamic acid, which is an amino acid. Although glutamic acid is naturally present in the human body, it is also present in many foods and ingredients.

MSG often serves as a flavor enhancer in canned foods, deli meats, soups, and restaurant meals. It has been in use for about 100 years Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source now. It is a popular ingredient in certain Asian dishes and processed Western meals because of its distinct taste, known as umami.

Umami has a meaty flavor that indicates that protein is present in the food. Umami is also considered one of the basic tastes, along with sour, sweet, bitter, and salty.

Why did people lose their trust in MSG?

A letter written on April 4, 1968, by biomedical researcher Robert Homan Kwok made many Americans start mistrusting MSG.

In Kwok’s letter, he described how he experienced strange symptoms — such as heart palpitations, numbness, and weakness — after eating at Chinese restaurants that cooked with the MSG flavoring.

Kwok’s letter, which the New England Journal of Medicine received, caught the attention of many scientists who went into comprehensive research to find out if MSG really is bad and whether or not it caused the unpleasant symptoms that Kwok experienced.

Is MSG safe? 

The Food and Drug Administration (FDA) Trusted Source Food and Drug Administration (FDA) Governmental authority Go to source considers MSG as generally safe when added to meals. The FDA does acknowledge that some people consider themselves “sensitive to MSG.” However, they note that studies have not been able to show that MSG consistently triggers reactions in such individuals.

‘Chinese restaurant syndrome’

In Kwok’s letter to the New England Journal of Medicine, he pointed out the fact that his symptoms may have also been caused by other dietary factors, such as alcohol and sodium. However, the publication only highlighted MSG as the main cause, calling his symptoms the “Chinese restaurant syndrome Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source .” 

Although some other people like Kwok have reported adverse effects after eating Chinese meals prepared with MSG, there is not enough evidence to conclusively link MSG consumption to those side effects. 

Read our tips for staying healthy when eating out here.

Safe levels of MSG

According to the FDA, people consume an estimated 0.55 grams (g) Trusted Source Food and Drug Administration (FDA) Governmental authority Go to source of MSG per day. The FDA asked the independent scientific group the Federation of American Societies for Experimental Biology (FASEB) to investigate MSG safety in 1995. 

The result of the FASEB investigation was that MSG is safe. However, the FASEB report indicated that sensitive people who consumed 3 g of MSG or more without food might experience mild symptoms, including numbness, tingling, headaches, and palpitations.

Still, it is very unlikely that people would consume up to 3 g of MSG at a time without food. 

One 2017 study Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source recommends MSG as an alternative to salt, as the World Health Organization (WHO) suggests a daily intake of no more than 5 g of sodium chloride (table salt) for adults.

Learn about salt cravings here.

MSG myths debunked

Some of the alleged health effects of MSG include the following.

Headaches

Some people say that they experience headaches after eating meals prepared with MSG. However, so far, evidence to suggest this is purely anecdotal. 

Some 2016 research Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source that reviewed different studies found no consistent result in the various studies carried out in humans. The researchers observed no statistically significant differences in the incidence of headache when MSG was administered with food and suggested that a relationship between MSG and headache has not been proven.

Learn about tension headaches and their possible triggers here.

Cancer

Some people still hold the belief that MSG consumption increases the risk of cancer. However, there is no evidence to support this claim.

Cancer is caused by changes (mutation) to DNA in cells. Some of the most common factors that can increase cancer risk include:

  • alcohol consumption
  • sun exposure
  • a sedentary lifestyle
  • aging
  • tobacco use
  • chemical exposure

Obesity

Older studies that linked MSG to diabetes and insulin resistance — which are also risk factors for obesity — had flaws in their methodology. For example, they used injections instead of oral doses. MSG only raises blood levels of glutamic acid if a person consumes it in very high amounts.

Dietary and lifestyle habits such as eating too much, eating high calorie meals, and having only low physical activity levels are the primary causes of obesity. 

There is currently not enough evidence to suggest that MSG contributes to overweight or obesity. More research is needed.

Read tips from doctors about weight management here.

Brain damage

One 2019 study Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source noted that even though some preclinical studies have linked MSG with low-grade inflammation and neurotoxicity, which can cause brain and nervous system damage, a review of the literature detected several methodological flaws. This led to the conclusion that such studies have limited relevance. 

Asthma

According to a 1987 study, 40% of people Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source given large doses of MSG experienced an asthma episode later.

However, one 2012 study Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source found no link between MSG in diet and asthma in adults. It is also very unlikely Trusted Source Food and Drug Administration (FDA) Governmental authority Go to source in real life settings for people to consume MSG in such large doses as in the 1987 study.

Learn about seven foods to avoid with asthma here.

Is it possible to have an MSG allergy?

People once believed that MSG could cause allergies, but recent evidence suggests that allergies to MSG are not possible. Although people may experience allergies to the foods MSG is added to, decades of research Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source have not found a conclusive relationship between MSG and serious allergic reactions. 

However, MSG sensitivity is possible Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source . Food sensitivities are different from allergies. Food sensitivities are also called “food intolerance,” and they are caused by negative reactions in the digestive system after eating certain foods — particularly in large amounts.

Allergies, on the other hand, are more serious. Allergies are caused by the immune system overreacting to certain foods and producing antibodies to attack them.

You may have MSG sensitivity if you experience the following symptoms after eating foods prepared with MSG:

Learn about food allergies here.

How is MSG produced? 

MSG is produced via a fermentation process. Fermentation is the same process used in making yogurt, beer, and vinegar.

MSG is produced by fermenting corn or sugarcane. Carbohydrates from these plants are fermented to produce glutamate. Manufacturers then purify, crystallize, and dry the glutamate to form a white crystal.

How is MSG used in food? 

MSG is used in different ways to prepare food. Many people use it to season their food, with many of them considering it umami. 

Some possible applications of MSG in food include:

  • dressings and sauces, such as mayonnaise, ketchup, and salad dressing
  • processed meats, such as hamburgers, bacon, sausages, smoked meat, and salami
  • fast foods and snacks, such as noodles, chicken nuggets, burgers, and fried potato chips
  • protein building powder
  • food spices

Some people also use MSG as a salt alternative Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source to reduce the sodium chloride content in foods such as soups, instant noodles, meat products, stocks and seasonings, milk products, and snacks.

Learn simple healthy habits to start here.

Alternatives to salt and MSG

Some people prefer to use MSG as an alternative to salt. This is because studies have shown that consuming too much salt can cause adverse health effects, including hypertension, stroke, and heart disease.

However, there are other alternatives that have a meaty flavor similar to MSG, such as:

  • beef stock
  • yeast extract
  • mushrooms
  • parmesan cheese
  • soy source
  • cheese
  • spices
  • flavored oil
  • oyster sauce
  • herbs

Summary

Some people avoid foods prepared using MSG due to the fact that some individuals have reportedly experienced unpleasant symptoms after eating meals cooked with this additive. However, recent studies have shown that some of the alleged health effects of MSG are likely only myths.

More research is needed to confirm the long-term safety of MSG.

The FDA also states that MSG is safe, especially when consumed in small doses in foods. However, it is possible to have MSG sensitivity.

If you notice mild symptoms — such as weakness, flushing, dizziness, headaches, difficulty breathing, numbness, and muscle tightness — after eating meals prepared with MSG, you should talk with your doctor. You may be sensitive to MSG. 

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Medical Reviewer: Jillian Kubala, MS, RD
Last Review Date: 2022 Jun 30
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