The side effects of MSG (monosodium glutamate) often include headache, rapid heartbeat, and drowsiness. Some people also report experiencing worsening of asthma symptoms, numbness, and chest pain. Not everyone experiences side effects of MSG, and side effects are most often experienced by people who have a sensitivity to the substance. Even though the side effects are not considered dangerous, people who frequently experience them may need to avoid foods that contain MSG the majority of the time. Some foods that contain lots of MSG are Asian foods, certain types of flavored snack crackers, and many different frozen dinners.
MSG is normally added to food to enhance its flavor, and the use of this substance can be traced back to Japan in the early 1900s when a professor at the University of Tokyo invented it. Many other countries quickly adopted the use of MSG for the purpose of flavoring food because the substance was cheap, effective, and readily available. MSG is made up of a substance created by the fermentation of starch and sugar. The brand name that MSG falls under varies from country to country, but there are no differences in the actual product apart from the brand name.
The side effects of MSG were not typically of much concern until the substance became so widely used. In spite of the side effects, most experts have concluded that MSG is not a dangerous substance. There have been many different studies and tests performed on MSG, and the results have been mostly inconclusive. Some studies have indicated that large doses of MSG could be harmful and might increase the risk for obesity and possibly brain lesions. These studies were done on animals, and most researchers have stated that the majority of people could not consume the amount of MSG necessary for these problems to occur.
A person who wants to avoid the side effects of MSG can do so by avoiding all food items that contain it. Avoiding MSG should be relatively easy when grocery shopping because the majority of nutrition information labels list it as an ingredient when it is present. Staying away from MSG in restaurants might be more difficult because most restaurants do not reveal the ingredients of the foods they serve. A person who has a sensitivity to MSG may want to speak with restaurant managers about her MSG sensitivity before ordering anything to find out if there are any MSG-free foods on the menu. It might also be a good idea for a person to avoid the majority of Chinese restaurants or other Asian restaurants because MSG tends to be a very common ingredient in foods served at these places.