Question: Are the flavor enhancers glutamate and monosodium glutamate bad for you? I have heard people say that they cause cancer and other problems and that it would be best not to eat foods that use them to enhance flavor.
Answer: My knowledge about these products is limited, but I do have a summary statement about them from the International Food Information Council, which is usually a reliable source.
Glutamate, an amino acid, occurs naturally in all protein-containing foods such as cheese, milk, mushrooms, meat, fish and many vegetables. The natural level of glutamate in food varies greatly but is high in foods such as tomatoes, mushrooms and Parmesan cheese. Glutamate is also produced by the body and is vital for metabolism and brain function.
Monosodium glutamate, or MSG, is the sodium salt of glutamate. When MSG is added to foods, it provides a similar flavoring function as the glutamate that occurs naturally in food. MSG is composed of nothing more than water, sodium and glutamate. MSG is made from starch, corn sugar or molasses from sugar cane or sugar beets using a natural fermentation process similar to that used to make beer, vinegar and yogurt.
The body treats glutamate that is added to foods in the form of MSG the same as the natural glutamate found in food, so it is probably not very harmful. According to the council's report, MSG is one of the most extensively researched substances in the food supply, and the United States and other governments worldwide support the safety of MSG as used in foods. Even infants, including premature babies, can metabolize glutamate effectively. In fact, glutamate is actually 10 times more abundant in human breast milk than in cow's milk.
The average American consumes about 11 grams of glutamate a day from natural protein sources and less than 1 gram a day from MSG. And, MSG contains only about one-third the amount of sodium as table salt (13 percent vs. 40 percent) and is usually used in much smaller amounts than table salt.
MSG cannot improve bad-tasting food or make up for bad cooking. It does not allow a cook to substitute low-quality for high-quality ingredients in a recipe and does not tenderize meat. It just makes good food taste better. You can tell if glutamate or MSG is added to foods because the U.S. Food and Drug Administration requires labeling of all ingredients on processed and packaged foods. When MSG is added to a food, it must be included on the ingredient list as "monosodium glutamate." Glutamate-containing food ingredients, such as hydrolyzed protein and autolyzed yeast extract, also must be listed on food labels. Of course, when glutamate is a component of natural protein foods, like tomatoes, it is not listed separately on the label.
MSG is not an allergen, according to the American College of Allergy, Asthma and Immunology, but it is possible for some people to be sensitive to it, just as some people are sensitive to many other foods and food ingredients. There have been reports of mild, temporary reactions to MSG in a small portion of the population, based on tests with a large dose of MSG in the absence of food.