If you've developed an odd reaction after eating a meal from your favorite Chinese restaurant, you may suspect that you're suffering from an MSG allergy. Monosodium glutamate (MSG) is a food additive that's added to many canned and processed foods, as well as Chinese food, to enhance flavor.
While an MSG allergy isn't outside the realm of possibilities, it's highly unlikely, according to the American College of Allergy, Asthma and Immunology (ACAAI). But you could be sensitive to the food additive, and to prevent another reaction, you may want to cut foods that contain MSG from your diet.
What Is MSG?
MSG is best known as an additive used to enhance the flavor of savory foods. But it's also naturally found in foods you may eat on a regular basis, including tomatoes and cheese. As an additive, the Food and Drug Administration (FDA) considers it "generally recognized as safe" or GRAS, which means that experts have found MSG to be safe for consumption when used for its intended purpose.
The property responsible for the flavor-enhancing element of MSG is glutamate, which is an amino acid naturally present in almost every food you eat. According to the FDA, in 1908 a Japanese professor isolated glutamate from a seaweed broth and discovered that it was responsible for the savory flavor of the soup. The professor filed a patent and began producing MSG from seaweed and other vegetables to use as a flavor enhancer.
Today, MSG is produced through fermentation, which is the same process used to make yogurt and wine, by combining a microorganism with sugar cane, sugar beets or molasses.
In its free form, glutamate adds a new dimension to the flavor of food referred to as umami. Your taste sensations were traditionally classified as sweet, sour, bitter and salty. With the advent of MSG, your tastes now include umami, which is described as a savory or meaty flavor.
MSG Versus Glutamate
Despite its GRAS status, you may still have some reservations about MSG. To be clear, MSG and glutamate are indistinguishable by your body. This means that whether you're eating an MSG food (the food additive) or glutamate foods (such as cheese or meat), your body metabolizes it in the same manner.
In fact, the majority of the glutamate you consume comes from whole foods, not MSG. According to the International Food Information Council Foundation (IFIC), MSG is simply the sodium salt of glutamate comprised of salt, glutamate and water.
Glutamate, also referred to as glutamic acid, is an amino acid. There are 20 different amino acids that your body uses to create the various proteins found in your body, such as muscle, digestive enzymes and skin. Nine out of the 20 amino acids are essential, which means your body can't manufacture them and you must get them from the food you eat.
Glutamate is not an essential amino acid, which means your body can produce it on its own, and because it's a primary amino acid, it's found in almost every peptide, protein and tissue in the body. Glutamate is essential for human metabolism and is found in abundant amounts in its free form in your brain, where it serves as a neurotransmitter to aid in the communication between your brain cells.
MSG is a source of sodium, but contains about a third less than table salt. Too much sodium in the diet increases your risk of high blood pressure and heart disease, according to the American Heart Association. MSG may add flavor to your food without the need for extra table salt and help to reduce your overall sodium intake.
MSG Food List
- Soup, broth, bouillon cubes
- Soy sauce, fish sauce, oyster sauce
- Miso, tempeh, soy protein
- Processed meats and fish, including ham
- Tomato and vegetable sauces
- Hydrolyzed vegetable protein
- Yeast extracts (Vegemite)
The FDA requires manufacturers to list MSG on the food label, so you can easily identify an MSG food and add it to your list. In addition to monosodium glutamate, MSG may also be listed as:
- Glutamic acid
- Calcium glutamate
- Disodium guanylate
- Disodium inosinate
- Disodium 5-ribonucleotide
Or it may be listed on the label as any ingredient that includes the word glutamate.
If you're trying to avoid MSG and you like savory snack foods, you may want to read the ingredient list carefully. Some of the most popular cheesy-flavored snacks, including Doritos and certain flavors of Pringles, contain the flavor enhancer.
Sensitivity to MSG
Adverse reactions to food additives like MSG are rare, according to the ACAAI. While allergic reactions have been reported, MSG isn't considered an allergen. If you're experiencing reactions when you consume a food with MSG, it's more likely a sensitivity to the MSG, not a true allergy.
For the record, an allergy occurs when your immune system overreacts to a substance it considers harmful, even though for most people, it's not. If you have an allergy to a food, it's recommended that you avoid it altogether to reduce your risk of anaphylaxis, which is a life-threatening condition. Only your doctor can diagnose an allergy. If you suspect you have a sensitivity to MSG or some other food or additive, talk to your doctor.
A food sensitivity doesn't cause an adverse life-threatening bodily reaction. Common symptoms reported with a sensitivity to MSG include:
- Chest pain
- Heart palpitations
- Numbness or tingling in the face or neck
According to Mayo Clinic, researchers have been unable to find a definitive link between these symptoms and MSG. In the rare instances when they have occurred, the symptoms have been mild and resolved on their own without the need for medical care.
Read more: Harmful Effects of Preservatives in Food
Effects on Appetite and Fullness
You may be fearful of consuming any food with MSG due to concerns about having a sensitivity or developing symptoms, but there's some evidence that MSG may stimulate the appetite and increase feelings of fullness.
The IFIC Foundation notes that MSG may potentially help increase appetite in older adults by improving taste sensations. The IFIC Foundation explains that as you get older, taste and smell sensations decrease, which may affect your desire to eat. A poor intake and dwindling appetite increase the risk of malnutrition and health complications.
A January 2018 study published in Appetite found that MSG added to carrot soup improved appetite and also had a satiating effect. This small study (28 participants) found that when MSG was added to soup it didn't affect food intake, but it did increase feelings of fullness and decrease the desire to eat. The researchers concluded that MSG may affect the hormones in your gut that control appetite.
While it may seem as though MSG has some potential benefits, the evidence is limited. Additionally, MSG is still a food additive that doesn't offer any nutritional value and may not contribute much to your overall health. When it comes to health, you're better off choosing a variety of whole foods from all the food groups and using herbs and spices that not only enhance flavor, but also add nutritional value.
- American College of Allergy, Asthma and Immunology: "Food Allergy: A Practice Parameter"
- Food and Drug Administration: "Question and Answers on Monosodium Glutamate"
- Food and Drug Administration: "Generally Recognized as Safe (GRAS) Notification Program"
- International Food Information Council Foundation: "Glutamate and Monosodium Glutamate: Examining the Myths"
- Colorado State University: "Physiology of Taste"
- MedlinePlus: "Amino Acids"
- Journal of Neural Transmission: "Glutamate as a Neurotransmitter in the Healthy Brain"
- Women's and Children's Health Network: "Low MSG Diet"
- Frito Lay: "Doritos"
- Kelloggs: Smart Label: "Pringles Cheddar Cheese"
- Mayo Clinic: "Allergies"
- Mayo Clinic: "What Is MSG? Is It Bad for You?"
- MedlinePlus: "MSG Symptom Complex"
- Appetite: "Acute Effects of Monosodium Glutamate Addition to Whey Protein on Appetite, Food Intake, Blood Glucose, Insulin and Gut Hormones in Healthy Young Men"
- American Heart Association: "Why Should I Limit Sodium?"