In the 1960s, the food additive monosodium glutamate (MSG) incorrectly gained a bad reputation because of fears that it could cause allergy-like symptoms and side effects. However, since the 1990s, researchers have largely debunked the existence of an MSG allergy.
While an MSG allergy is a myth, some claims still exist on the internet. There are also clinical studies that have assessed possible negative reactions from this ingredient, but they’re not representative of the small amounts humans typically consume in foods.
It is possible to experience allergies to the food MSG is in, as opposed to an allergy to the additive itself. The
Here’s what you need to know about MSG, the rise and fall of the MSG allergy myth, and what you can do if you’re experiencing possible symptoms of a food sensitivity or allergy.
MSG is a flavor enhancer made from L-glutamic acid, which is a naturally occurring amino acid that
It occurs naturally in many foods and is
Is it the same as salt?
Table salt is an ionic compound made up of a 1-to-1 ratio of sodium (Na) and chloride (Cl) ions, through which table salt derives its chemical formula NaCl (sodium chloride). The positively charged sodium ions and negatively charged chloride ions are bound together in a solid structure by electrical attraction.
MSG also is another ionic compound that contains both positively charged sodium and negatively charged glutamate ions, but not in a 1-to-1 ratio.
The ratios are 12 percent sodium ions, 78 percent glutamate ions, and 10 percent water, which results in the chemical formula (C5H8NO4–).
Because it contains sodium, MSG is able to
Despite concerns, decades of research have mostly failed to demonstrate a relationship between MSG and serious allergic reactions. People have reported reactions after eating foods with MSG, but human studies haven’t supported this anecdotal information.
Is MSG safe?
In 2016, researchers found that any amount of MSG is genotoxic, meaning it’s damaging to cells and genetic material, as well as to human lymphocytes, a type of white blood cell. However, the study found that these effects were in vitro, meaning the tests were done in a test tube. The results don’t support the theory that eating MSG is harmful in the same way.
In 2015, researchers
Nevertheless, further research in humans may be warranted to completely rule out sensitivity to foods with MSG.
- skin flushing
- numbness and tingling
- heart palpitations
Still, while the existence of an allergy to MSG has largely been debunked, it’s still possible that you might have a sensitivity or allergy to the actual food containing MSG.
Food additive sensitivities are also possible.
Food sensitivity vs. food allergy
It’s important to understand the differences between food sensitivities and allergies. Also referred to as food intolerance, food sensitivity occurs due to negative reactions in the digestive system.
While you might experience uncomfortable symptoms, a food sensitivity is unlikely to cause problems if you eat the food in small amounts. The symptoms may also occur within a few hours of eating the food, but will also go away on their own.
Signs of possible food sensitivity may include:
- itchy skin
- skin rashes
- abdominal pain
Food allergies, on the other hand, are much more serious. These occur as a result of your immune system overreacting to certain foods and creating antibodies to attack them.
Unlike food sensitivity, some people might have life threatening reactions if they have severe food allergies. Symptoms develop quickly, sometimes even after just touching the food.
Symptoms of a food allergy may include:
- red skin, hives, or eczema rashes
- skin swelling
- respiratory symptoms, such as wheezing or shortness of breath
- swelling in the throat
- anaphylaxis, a life threatening reaction that may lead to unconsciousness
If you experience any negative symptoms after consuming an MSG-containing food, it’s important to see a doctor for the next steps, including possible testing for food intolerance or allergies.
According to the FDA, consuming larger doses of MSG —
However, not only are those portions unlikely to be found in restaurant or grocery food, it’s unlikely that anyone would consume MSG in non-food sources. The FDA says the typical MSG serving in food is 0.5 grams or less.
The best way to treat a food intolerance or allergy is to avoid the food that’s causing your symptoms. However, you may need blood or skin tests to confirm any food allergies or sensitivities before making any significant dietary changes. Your doctor may also recommend a food diary or elimination diet.
More serious symptoms, such as anaphylaxis, require emergency treatment in the form of a shot of epinephrine (adrenaline). Hospitalization may also be required.
When to seek emergency help
Anaphylaxis is a life threatening allergic reaction that requires immediate medical attention. Call 911 or go to your local emergency room.
- shortness of breath
- swelling of the lips or throat
- heart palpitations
- chest pain
The best treatment for a food allergy is to avoid eating that food.
What foods contain MSG?
It may be hard to avoid foods with MSG. According to the U.S. Department of Agriculture (USDA), MSG occurs naturally in many foods. It’s particularly found in high doses in food that is high in protein, such as:
With regard to foods that contain MSG as an additive, labeling is required when the compound is added as an ingredient. In those cases, it’s listed as “monosodium glutamate.“
Substances to avoid that may contain added MSG include:
- frozen foods
- spice mixes
- canned or dry soups or stocks, which food labels may refer to as “dried beef,” “chicken stock,” “pork extract,” or “hydrolyzed wheat protein“
- sauces and salad dressings
- meat-based foods like sausage
While there was once a belief that MSG could cause allergic reactions in some people, the overall existence of an MSG allergy has been largely declared a myth.
MSG itself naturally occurs in some foods, such as meats, and is added to other types of processed foods to help preserve flavor. While it’s possible to have either a food sensitivity to MSG or any MSG-containing foods, there’s no scientific evidence to prove that the food additive causes allergies in humans.
If you experience unusual symptoms after eating particular food items, see your doctor for possible testing. Any suspected sensitivities to MSG or MSG-containing foods may be resolved by avoiding these items altogether.