Poor food quality is a growing problem in industrialized countries increasingly focused on the quantitative dimension of food production, both in terms of the sheer volume of food produced, as well as the revenue and profit generated. In the United States, for instance, consumers do not even have the right to know what is in their food, e.g. genetically modified ingredients are not labeled by default; the use of paint pigment (titanium dioxide) as a "manufacturing aid" in milk, not required to be listed as an ingredient on the label, etc, and raw human sewage and factory-farmed animal waste, as well as petroleum and coal byproducts, are all considered fair game as a growing medium in USDA-approved conventional farming practices.
Given these deteriorating market conditions, our bodies, which spent eons evolving complex sensorial and cognitive pathways to determine whether something was good, or bad, based on appearance, taste, smell, etc., are increasingly being chemically manipulated through food science trickery. And as the food in its unadulterated state becomes more and more unappetizing, if not clearly disgusting, the slick marketing and associated nutritional disinformation becomes less and less effective on the consumer. Enter MSG, a virtual miracle worker when it comes to turning disgusting into delicious....
Turning Yucky To Yummy With The MSG Sleight of Hand
Monosodium glutamate (MSG) is a commonly used "flavor enhancer," and so powerfully so that (hyperbole permitting) you could spray it on roadkill and it would taste good. This omnipresent ingredient in modern mass market food takes advantage of our biologically hard-wired taste receptors, and makes it very hard to stop eating the foods "seasoned" with this ingredient. In fact, it is doubtful that without the MSG trick many of these mass market processed foods would be palatable enough to maintain their status as economically viable commodities. Here are some of its many disguises on food labels....
- Glutamic Acid
- Hydrolyzed protein
- Autolyzed protein
- Textured protein
- Yeast extract
- Autolyzed yeast extract
- Protein isolate
- Soy sauce
- Modified food starch
- Modified corn starch
- Calcium caseinate
- Sodlium caseinate
- Natural flavor
- Monopotassium glutamate
- Hydrolyzed vegetable protein
- Hydrolyzed plant protein
- Textured protein
- Yeast food
- Yeast nutrient
- Torula yeast
Technically MSG is the sodium salt of glutamic acid, a naturally occurring non-essential amino acid. Glutamic rich foods include wheat, dairy, corn, soy, seafood, etc. (Foods Highest In Glutamic Acid). The "YUMMY!" sensation that occurs immediately after ingesting a MSG (or various synonyms, e.g. hydrolyzed protein, autolyzed yeast) laced morsel the Japanese call umami (meaning: savoriness) and is considered one of five basic tastes.
The problem is that when one isolates out of a complex food a singular amino acid, and increase the concentration to unnatural proportions (and without the hundreds of checks and balances Nature provides in the context of a whole food), glutamic acid can have devastating health effects, not the least of which is the generation of an insatiable appetite for more of the very same chemical stimulating the craving -- a vicious, self-amplifying cycle!
Monosodium Glutamate Causes Excitotoxicity
One of the primary adverse effects associated with excess glutamic acid is excitotoxicity, a form of neurotoxicity where neurons are stimulated to the point of cell death. Repeated excitotoxic events can result in neuronal lesions and loss of cognitive function.
While there are a number of natural substances that mitigate this type of excitotoxicity, the best choice is to reduce the consumption of glutamic acid (as well as its "twin" excitotoxic non-essential amino acid aspartic acid) rich foods, especially if there is a pre-existing neurological condition such as migraines, epilepsy or multiple sclerosis, to name but a few. John Symes has written an excellent document on the benefits of the Glutamic and Aspartic Acid Reduced Diet (GARD Diet) here.
More Than An Excitotoxic Agent: An Endocrine Disruptor
Recently Dr. Mercola featured the connection between MSG and obesity. While excessive food cravings caused by MSG's taste-enhancing effects figure into this relationship, research from the US National Library of Medicine indexed on our site shows that MSG may directly cause hypothalamic lesions that result in elevated insulin, insulin resistance and leptin resistance (leptin suppresses appetite).
It is becoming clear that MSG can no longer be considered simply a "flavor enhancer" but an intrinsically harmful chemical with endocrine disruptive properties. Research we have collected shows that MSG actively contributes to metabolic syndrome, obesity, fatty liver, dysregulated blood lipids, as well as a wide range of neurological problems.
In a nutshell, monosodium glutamate (MSG) contributes to illness in two distinct ways:
1) It makes food that is bad for us taste really, really, really good, in essence compromising our health by tricking our taste buds and intuition into eating things that are intrinsically harmful, or harmful when eaten excessively.
2) It is a toxic chemical that directly damages neurological tissue through its excitotoxic properties, as well as inducing a generalized endocrine disruption throughout the body known as "metabolic syndrome," the symptoms of which include hypertension, insulin resistance, elevated blood lipids and/or elevated blood sugar.  
 Effect of trans-fat, fructose and monosodium glutamate feeding on feline weight gain, adiposity, insulin sensitivity, adipokine and lipid profile. Br J Nutr. 2011 Mar 24:1-10. Epub 2011 Mar 24.
 Effect of dietary monosodium glutamate on trans fat-induced nonalcoholic fatty liver disease. J Lipid Res. 2009 Aug;50(8):1521-37. Epub 2008 Nov 11.
 Effects of bezafibrate in nonalcoholic steatohepatitis model mice with monosodium glutamate-induced metabolic syndrome. Eur J Pharmacol. 2011 Jul 15;662(1-3):1-8. Epub 2011 May 1.