Food Additives, Part I

by Colleen Kaemmerer

Here's your lunch...would you like some MSG with that? You may not have a choice. MSG (monosodium glutamate) is a flavor enhancer commonly added to many processed foods.

Food additives are often a source of controversy and there is a wide spectrum of opinion about their safety. While food additives don't cause an allergic reaction involving the immune system, many people find they have adverse reactions which can be severe. Often, people dealing with allergies, either their own or a family member's, are quite interested in the impact of food additives. Basically, I would like to present a variety of web-based information on this topic. In part 1, I'd like to take a look at a very common food additive - MSG.

According to the Center for Food Safety and Applied Nutrition (CFSAN), a part of the Food and Drug Administration (FDA), MSG is actually one of several chemicals known as glutamates. In the human body, glutamates act as nerve impulse transmitters in the brain and other glutamate-responsive tissues. The CFSAN states that "MSG and related substances are safe food ingredients for most people when eaten at customary levels." The CFSAN further explains that MSG is a sodium salt of the amino acid known as glutamic acid. It is manufactured by a fermenting process using starch, sugar beets, sugar cane, or molasses. Hydrolyzed proteins are also glutamates. They are acid-treated or enzyme-treated proteins and contain salts of free amino acids such as glutamate. Hydrolyzed proteins are frequently added to processed foods. Glutamates also occur naturally in foods; however, MSG (glutamate) reactions are usually due to processed, "free" glutamates.

In 1995, the Federation of American Societies for Experimental Biology (FASEB) concurred with the FDA's belief that MSG is generally safe. The FASEB report said that an "unknown percentage of the population may react to MSG and develop MSG complex." Some of the symptoms listed are:

  • numbness
  • tingling
  • headache
  • nausea
  • rapid heartbeat
  • difficulty breathing

Some possible reactions to MSG include:

  • headaches
  • migraines
  • stomach upset
  • nausea, vomiting, diarrhea
  • asthma attacks
  • heart palpitations
  • mental confusion
  • mood swings
  • behavioral disorders (especially in children and teens)
  • skin rashes

Processed foods with pure MSG as an ingredient must have it identified. However, other forms of glutamate may not be recognizable in the ingredient lists. Even if the label says "no MSG", other glutamates, which can cause the same reaction, may be in it.

Definite sources of MSG include:

  • hydrolyzed protein
  • sodium caseinate
  • calcium caseinate
  • autolyzed yeast or yeast extract

Possible sources of MSG include:

  • textured protein
  • carrageenan
  • seasonings or spices
  • bouillon, broth, or stock

At you can find a good bit of information about MSG and other glutamates. According to the Truth In Labeling Campaign, MSG reactions can be immediate or occur as late as 48 hours after ingestion. Also, reactions can be "dose-related", meaning that some people can not tolerate any MSG, while other people can tolerate varying amounts before having a noticeable adverse reaction. In addition, reactions can be cumulative, so that a person can, for example, eat a product with MSG once a week without ill effect, but eating the same product two or three days in a row can cause a reaction.

© Colleen Kaemmere

Colleen Kaemmererwas a contributing editor to's Allergies site.