Ask the Nutritionist
Q:
What exactly is MSG?
Meghan T., Bloomington, IN
A:
MSG, or monosodium glutamate, is derived from glutamic acid, which is one of the 20 most common amino acids (building blocks of protein) and is involved in cognitive functions like learning and memory. Glutamic acid naturally occurs in many foods such as meat, poultry, milk and vegetables.
MSG can be created from glutamic acid naturally or can be manufactured: it may be broken down in our bodies through digestion or made “free” through various chemical processes. The resulting MSG is a white crystal resembling sugar that is odorless and said to taste sweet or salty.
MSG is a drug; about 30 percent of the population has adverse reactions to MSG. Over-stimulation of glutamate receptors on our cells, such as that which occurs when consuming MSG, may lead to a variety of health problems from headaches to neurological disorders. MSG intolerance is not simply an allergic reaction, but rather a true drug reaction.
Like caffeine, monosodium glutamate occurs naturally in some foods. Free glutamate occurs naturally in foods such as tomatoes or mushrooms, which is why these foods are often used for their flavoring qualities. Also, like caffeine, monosodium glutamate is okay to consume in moderation. According to the U.S. Food and Drug Administration, “MSG and related substances are safe food ingredients for most people when eaten at customary levels.” Furthermore, only two groups of people may develop a condition known as “MSG symptom complex.” This includes those who may be intolerant to MSG when eaten in a large quantity and people with severe, poorly controlled asthma who may suffer temporary worsening of asthmatic symptoms after consuming MSG. The MSG dosage that produced reactions in these people ranged from 0.5 grams to 2.5 grams.
The biggest concern consumers should have with MSG is that the additive MSG masks inferior quality or freshness of foods and for this reason is most commonly found in processed and prepared foods and in restaurant meals. MSG has no nutritional value nor is it a preservative as some tend to think. MSG is added to foods as a flavor enhancer; the MSG itself does not change the flavor of food, but over-stimulates brain cell activity to “trick” the brain into thinking that the food tastes better.
To reduce your consumption of MSG-containing foods, limit the amount of processed and prepackaged foods in your diet. Avoid flavorings, meat seasonings, soy sauce, bouillon, broths, stocks, syrups, cornstarch and milk powder. And keep the following in mind when reading ingredient labels:
- “No MSG added” may mean that MSG was not added to the final prepared food, but MSG may have been used to prepare the food.
- “Free glutamate” is another term for MSG.
- If hydrolyzed protein is in the ingredient list, the product contains MSG.
- Many flavorings include MSG; therefore be on the lookout for term “natural flavors.”
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