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Top 10 Most Common Ingredients in Fast Food

Monosodium Glutamate: The Most Common Flavor Enhancer

Monosodium glutamate, or MSG, earned its reputation in Asian takeout kitchens across America, but almost all fast-food restaurants use the flavor enhancer to some extent. Interestingly, MSG has no distinct taste itself. Instead, it amplifies other flavors, especially in foods with chicken or beef flavoring, through processes that scientists don't fully understand.

MSG is the sodium salt of the amino acid glutamic acid and is just one form of glutamate, a chemical that exists naturally in many living things. In fact, Asians historically used a broth made from seaweed as their source of MSG. Today, the food industry obtains the white powder through a fermenting process involving carbohydrates such as starch, sugar beets, sugarcane or molasses.

The safety of MSG has been in question for many years. In 1959, the U.S. Food and Drug Administration classified MSG as a "generally recognized as safe" substance. Then, in the 1980s, researchers began to wonder whether chemicals in the glutamate family could harm brain tissue based on studies that revealed glutamate's role in the normal functioning of the nervous system. An extensive FDA-sponsored investigation has since determined that MSG is safe when consumed at levels typically used in cooking and food manufacturing, although two groups of people -- those who eat large doses of MSG on an empty stomach and those with severe asthma -- may experience a set of short-term adverse reactions known as MSG Symptom Complex.

No such complex is associated with the next ingredient on our list.