Does MSG Get a Bad Rap?

August 30, 2023

Heap of monosodium glutamate on wooden spoon

Monosodium glutamate, or MSG, is a common flavor enhancer used in many foods. Claims that the additive is harmful to health have fueled controversy and fear. University Hospitals registered dietitian Jennifer Kerner, RD, LD, shares the latest research on this controversial ingredient.

What is MSG?

MSG is made from sodium and L-glutamic acid. This naturally occurring amino acid is present in many high protein foods including beef, chicken, some fish and shellfish, as well as in some vegetables including tomatoes, broccoli, cabbage, onion and spinach.

When processed into a white crystalline powder similar to table salt, MSG is used to enhance the flavor of many foods such as cheeses, processed meats, canned and frozen foods, sauces and dressings, seasoning blends, and snack foods like chips and crackers. In addition, MSG is often used as a seasoning in Asian dishes and fast-food restaurant menu items.

Is MSG harmful?

Although MSG has been used as an additive for nearly a century, the concern began in the 1960s when reports began circulating about harmful side effects. Some early MSG studies supported the claim of toxicity, but many of those studies were flawed by poor methods, limited sample sizes and excessive intake of MSG.

“Based on recent studies, the Food and Drug Administration and most experts agree that MSG is safe in the moderate amounts found in a normal diet,” says Kerner.

Research shows that MSG is safe when consumed as part of a normal diet – up to 14 mg per pound of body weight or roughly 2.5 grams for a person who weighs 150 pounds. Kerner notes that the average person’s daily intake of MSG is less than 1 gram.

What are the potential side effects of MSG?

Fewer than 1 percent of people may be sensitive to MSG and experience mild, short-term symptoms including headache, flushing, weakness, numbness or tingling, heart palpitations, chest pain, difficulty breathing and nausea.

For most people who report symptoms, there is no evidence directly linking their symptoms to MSG content. MSG is often used to enhance flavor in highly processed foods, which may contribute to the perception of symptoms.

Is MSG worse than salt?

Many people are surprised to learn that MSG contains one-third the amount of sodium as table salt. “If a person needs to follow a low sodium diet, they should be limiting their sodium intake, regardless of the source,” says Kerner. “MSG can offer a strategy to decrease sodium intake if used in place of salt.”

“Because some people may be sensitive to MSG, the FDA requires that foods containing the additive must include it on the label. The best advice is to check food labels, especially if you’re sensitive, and avoid too much MSG in one sitting.”