Home Health & Fitness Monosodium Glutamate or MSG: What’s the Big Deal?

Monosodium Glutamate or MSG: What’s the Big Deal?


Is MSG harmful to the human body?  What does it do for and to the human body?  To answer these questions one first must determine how we get MSG and how it impacts the body.  In short, MSG has been used as a food additive for flavor enhancement for decades. The Food and Drug Administration (FDA) has classified MSG as a food ingredient “generally recognized as safe,” however the use of MSG remains controversial. For this reason, when MSG is added to food, the FDA requires it be listed on the label.

The taste enhancers of which MSG is marketed, include free monosodium glutamate and free monosodium aspartate, are used in large amounts in processed food, as MSG, or in a number of other sources such as hydrolyzed vegetable protein, enzymes, broth, natural flavorings or other names such as: “umami”, MSG, glutamate, free glutamic acid and E-621.  And according to the New York Times April 6, 2005 article “Food Companies Test Flavorings That Can Mimic Sugar, Salt or MSG”:


MSG is a salt of the amino acid (Glutamic Acid (glutamate)).  A salt is the chemical name for a molecule held together by opposite charges.   Basically one (mono) sodium atom is “stuck” to the amino acid glutamate. MSG stimulates the pancreas to produce insulin when there doesn’t even have to be carbohydrates in the food for that insulin to act on.  The blood sugar drops because of the insulin flood, and you are hungry an hour later”.

Sound familiar?  A second reason why manufacturers of MSG add it to food is the addictive effect it has on the human body. It’s a convenient way to keep consumers coming back for more. Better than simply explaining how MSG reacts in the body, an illustration may be in order.  No strain of rat or mice is naturally obese, therefore scientists have to create them. They make these morbidly obese creatures by injecting them with a chemical (MSG) when they are first born. The MSG injected into the infant mouse triples the amount of insulin the pancreas creates, causing rats (and humans?) to become obese. A team of scientists in the Faculty of Medicine at the Complutense University of Madrid has discovered that when given to rats, E-621 produces a massive 40 percent increase in appetite.

The scientists are studying if the addictive substance affects the arcuate nucleus area of the brain and how it could prevent proper functioning of the body’s appetite control mechanisms. According to this hypothesis, people (and children) who consume foods with large quantities of E-621 just feel more and more hungry the more they eat. (Gobatto et al, 2002).

So What?  If MSG makes the body hungrier and we eat more due to the hunger, it makes sense obesity may follow.

So what foods include MSG?  MSG is in everything! The Campbell’s soups, the Hostess Doritos, the Lays flavored potato chips, Top Ramen, Betty Crocker Hamburger Helper, Heinz canned gravy, Swanson frozen prepared meals, Kraft salad dressings, especially the ‘healthy low fat’  foods. . The items that didn’t have MSG had something called Hydrolyzed Vegetable Protein, which is just another name for Monosodium Glutamate (MSG).

So What Does a Parent Do?  Five good rules of thumb are: (Hoernlein, 2011 and DiDanato, 2011):

  • The more salty a processed food is, the more likely it is to contain MSG or free glutamate.
  • The more processed a food is, the more likely it is to contain MSG or free glutamate:  powdered stuff that used to be food is likely to have added MSG because the original flavor has been degraded, AND processing concentrates and frees glutamate already bound and present.
  • The more ingredients in a packaged food, the more likely MSG is present.  Read labels carefully. Time is money.  If a food has more than five ingredients and you don’t have half an hour to read one ingredient label – put it back on the shelf – you’ll be better off.
  • Do not trust something simply because it is in a health food store and the label states it is natural or even organic. The US allows “natural flavors” to include protein hydrolysates which can contain up to 20% MSG by weight.  A distinction without a difference.
  • Also, read the labels of those which claim No Added MSG.  Manufacturers can state this because they did not add any additional MSG, discounting the MSG is already present in another form, such as hydrolyzed protein.

We live in an age of single parent households and households with both parents present but working outside the home.  We tend to eat foods that are processed and/or pre-cooked so that we can simply heat our food in a microwave and quickly be ready to eat.  We also eat out more often than any previous generation.

The net effect of this is that even when we try to “watch what we eat” we may be setting ourselves up for failure because of the effects on our digestive system caused by products such as MSG.  The mythical Trojan Horse may be in our midst today and may come pre-packaged from our supermarkets and restaurants.

About the Authors:

Amber Magner is a doctoral student in Sport Management at the United States Sport Academy.  She serves as a Teaching Assistant among her other duties.  Dr. Phillips is Chair of Sport Studies at the United States Sport Academy.  For more information about Academy programs, go to http://ussa.edu.


  • DiDonato, Kevin. (2011). The 5 Sneakiest Label Claims of All Time.  Retrieved May 31, 2011. http://www.getprograde.com/sneaky-label-claims.html
  • Gobatto CA, Mello MA, Souza CT, Ribeiro IA. (2002). The monosodium glutamate (MSG) obese rat as a model for the study of exercise in obesity. Res Commun Mol Pathol Pharmacol. 111(1-4), 89-101.


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