Few foods are surrounded by as much controversy and conflicting information as monosodium glutamate, or MSG. Adding to this confusion are the many hidden sources of MSG.
What is it doing in our food… and to our bodies?
If you’ve been confused about MSG, it’s no wonder. The FDA classifies the substance as GRAS (generally recognized as safe), and cites studies, including one commissioned by the agency in the 1990’s, backing this conclusion. However, there is equally compelling evidence to support the belief of a growing number of doctors and organizations that “MSG is poison, it’s causing widespread disease and it ought to be banned.”
What is MSG, really? What is it doing in our food, and to our bodies? What about its effects in pregnancy and on young children? Is it safe or not? Should you be concerned?
What is MSG?
MSG, or monosodium glutamate, is the sodium salt of glutamic acid, a non-essential amino acid common in many foods and naturally present in our bodies. (Glutamic acid refers to the amino acid when it is dissolved in liquid; as such it has a negative charge. When glutamic acid is combined with a positively charged salt to form a molecule (like MSG), it’s referred to as glutamate.)
Because it’s an amino acid (building block of protein), glutamic acid is found naturally in many foods that are high in protein, such as cheese, meat and milk. You might be surprised to learn, though, that many vegetables – such as tomatoes and mushrooms – and grains (including many gluten-free grains) also contain a significant percentage of glutamate. Soy beans and seaweeds are also rich natural sources of glutamic acid.
Glutamic acid was first isolated from seaweed in 1908. Most MSG today is manufactured through a process of bacterial fermentation. Other foods and food additives containing manufactured glutamic acid (such as autolyzed yeast extract) are made by various fermentation, chemical hydrolysis or autolysis, and/or enzymatic processes.
What is the role of glutamic acid in our bodies?
Don’t be deceived by the “non-essential” designation of this amino acid. This simply indicates that the human body can manufacture it out of other amino acids. Glutamic acid actually plays a crucial role in our nervous system.
Glutamic acid acts as a nerve cell messenger molecule, or neurotransmitter. Neurotransmitters are chemicals responsible for transmitting a signal from a neuron to another cell. Their proper functioning is necessary for the body to accomplish nearly any process.
Glutamic acid is classified as an excitatory neurotransmitter. This means that it stimulates the target cell to action. While not the only excitatory neurotransmitter, it is considered to be the most important in mammalian brains. A majority of cells in the nervous system are equipped with glutamate receptors.
Glutamate is important for cognition and learning. However, it must be present in the right amounts. Normally, the body regulates the amount of a neurotransmitter to enter the nerve cell and excite it to stimulate a response, then quickly clears the neurotransmitter away. When there is an overabundance of excitatory neurotransmitters, and/or they are allowed to stay too long, the nerve cell can remain in an excited state.
This is toxic to the cell. Neurotransmitters that overstay their welcome, or are too abundant, are therefore known as excitotoxins. If they are allowed to stay long enough, they will keep on exciting the neuron until it dies.
Free Glutamate vs. Bound Glutamate
In foods, glutamates can occur either bound to a protein or free. Most of the naturally-occurring glutamate in foods is bound to other amino acids. However, it’s possible for glutamates to break away and exist “free” as isolated versions of the molecule.
The body normally can regulate its glutamate and glutamine (a closely related amino acid that the body makes from glutamic acid exposure because it’s only the free version of the molecule that acts to excite the nerve cells. When more free glutamine is needed, the body manufactures only as much as it needs from naturally occurring bound glutamates and glutamines in the diet.
What are the health effects of MSG?
Here’s where most of the controversy surrounding MSG lies. It’s well-documented that in certain sensitive individuals, eating foods seasoned with MSG can result in various uncomfortable symptoms, most notably headaches, flushing, sweating, numb sensations, heart palpitations, nausea and weakness.
However – and despite the FDA’s insistence that the substance is safe – there is abundant anecdotal and scientific evidence that ingestion of MSG (and other glutamate-containing ingredients) is linked to a multitude of ailments, including:
- Obesity (in fact, MSG is used to induce obesity in lab animals)
- Retinal degeneration
- Reproductive disorders
- Irritable bowel
- Behavior problems
- Learning disabilities
- Heart irregularity
- Sudden cardiac death (including a rising number of cases occurring in high school and college athletes)
Most of these ailments are thought to result, at least in part, from frequent, long-term exposure to MSG and other glutamates added to the diet.
Why is MSG (and other glutamate-containing food) so popular?
In fact, Kikunae Ikeda, the Japanese professor credited with discovery of MSG, identified the flavor sensation it imparts as an additional taste distinct from the traditional four tastes of sweet, salty, bitter and sour. The most appropriate English word to describe it is “savory,” but the Japanese word “umami” (which means, basically, “yummy”) has come into common parlance.
If you’re wondering whether that newest fast-food fad, the Umami Burger, has anything to do with glutamic acid, you’re dead on. In an interview with New Yorker blogger Dana Goodyear, Umami Burger’s founder, Adam Fleishman, revealed that he was inspired to start the restaurant chain while researching what makes fast food taste so good. The entire point of the Umami Burger is to maximize the amount of glutamic acid (including MSG) in the food.
“Umami burgers,” reports Goodyear,” are greasy, juicy, and fat, with a deep, pickley tang; they stuff you, and make you want more.”
In fact, MSG is well known for having an addictive effect – doubtless the reason the food industry is so enamored of it. That, and the fact that its flavor-enhancing qualities can make even low-quality food palatable.
MSG first entered the Western diet in military rations, a practice learned from the Japanese during World War II. By making the notoriously unpalatable C-rations taste better, it was thought to enhance morale and help our soldiers perform better on the battlefield.
But it wasn’t long before the food industry discovered that adding MSG to canned soups and other prepared foods increased sales of the products without significantly increasing cost of production. Today, it’s hard to find a packaged food that doesn’t contain MSG or some sort of free glutamate – even if it doesn’t say MSG on the label.
Don’t manufacturers have to label MSG-containing food?
Yes and no. According to the FDA’s website,
“FDA requires that foods containing added MSG list it in the ingredient panel on the packaging as monosodium glutamate. However, MSG occurs naturally in ingredients such as hydrolyzed vegetable protein, autolyzed yeast, hydrolyzed yeast, yeast extract, soy extracts, and protein isolate, as well as in tomatoes and cheeses. While FDA requires that these products be listed on the ingredient panel, the agency does not require the label to also specify that they naturally contain MSG.”
In other words, manufacturers are free to add as much MSG as they want to food, as long as it’s hidden within another ingredient that has a recognizable common name. And the majority of them take full advantage of this loophole. Added glutamates have become so ubiquitous in our food that finding prepared foods that don’t contain them can be a challenge: TruthInLabeling.org has compiled a list of over 40 separate ingredients that always or often contain MSG or related substances / hidden sources of MSG, including but not limited to “stock,” “broth,” “yeast extract,” anything “hydrolyzed” or “autolyzed,” and even “natural flavors.”
But it’s not just in food anymore. MSG and other sources of free glutamate are often added to shampoos, conditioners, sunblocks, insect repellents, and cosmetics in the form of hydrolyzed proteins. (Look for the words “hydrolyzed,” “protein,” or “amino acids.”) According to Truth In Labeling, there have been reported cases of sensitive people reacting even to these topical products.
Is there a difference between MSG and naturally-occurring glutamates?
This is actually one of the most controversial aspects of the entire MSG debate. MSG proponents (like the industry-sponsored website MSGfacts.com claim that there is no detectable difference between manufactured and naturally-occurring glutamates, or in the way they are metabolized by the body.
Detractors of MSG disagree. They point out that a large proportion of glutamates present in most natural foods are bound to other proteins. This results in a slow release of the substance that the body is well-equipped to handle.
However, there are some foods, such as Parmesan cheese, that naturally contain high levels of free glutamate. Food scientist Carol Hoernlein explains why manufactured glutamates may differ from these naturally occurring free glutamates:
“There are contaminants in processed MSG. An analogy that can be used is that there are right-handed amino acids and left handed ones. They are like mirror images of each other. Processed MSG contains not only the kind of amino acids the body is used to handling, but mirror image ones too. This may cause problems because it is like putting the wrong glove on your hand. It’s not quite the same. We don’t exactly know what problems this may cause.”
Should I be concerned? MSG, Children, and Pregnancy
Neurosurgeon Russel Blaylock, M.D. explains that the amount of MSG in Western diets has been steadily increasing since it was first introduced just after World War II, and the amount humans are consuming is analogous to the amount that’s been shown to cause lesions in animals’ brains (when you take into account the fact that humans are approximately five times more sensitive to the substance than lab animals.)
Young children, in particular, seem to be especially susceptible to MSG sensitivity because of their developing brains and nervous systems. MSG is particularly destructive of the hypothalamus, a hormonal control center that regulates, among other things, hunger and thirst, the sleep-wake cycle (attention, new parents!) and emotional response. One clinical nutritionist has suggested a link between MSG consumption and dyslexia and rage in young children.
According to Dr. Blaylock, MSG is capable of passing through the blood-brain barrier and causing lesions on the brain tissue itself. “This is a very toxic substance, particularly to the developing brain, so if a mother is consuming it while she’s pregnant in these high amounts, it not only passes through the placenta to the developing baby, but the concentration of glutamate in the baby’s blood is twice as high as the mother’s.”
Putting two and two together, could MSG be involved in the precipitous rise of obesity, autism, ADD and other diseases affecting an increasing number of our children? It seems plausible. At least, quite plausible enough to justify taking a good hard look at our diets, our (and our children’s) health, and the potential risk factors to determine whether we feel at risk enough to change the way we eat.
MSG and your family
Of course, each family has to decide for themselves how to approach MSG. To be fair, there have been plenty of respectable studies that failed to indicate that the substance is anything but safe. And it’s important to realize that eliminating MSG entirely represents not just a change in diet, but a significant alteration of lifestyle.
Truly avoiding MSG and related substances requires massive vigilance, including significant time devoted to self-education; scrutinizing labels; preparing homemade alternatives and/or sourcing hard-to-find commercial alternatives to favorite MSG-laden foods; doing due diligence when eating out; and (probably the most challenging) having to explain one’s dietary choices (and possibly bring special food for one’s family) when attending pot lucks, birthday parties, and other social events involving food.
Is it worth it?
For some, the answer is no. If your family is not facing health challenges of any sort, you may not need to worry too much, especially if the added stress of complete MSG avoidance would put you over the edge. (Although be careful that you don’t discount those little annoying things that you just “live with.” Small symptoms like a perpetually runny nose, buzzing ears, or a little extra chub can be warning signs of larger, long-term problems. They are worth being concerned about – and finding the root cause of.
Just as a precaution, even if you don’t feel up to avoiding it altogether, you might want to take small steps to reduce your family’s exposure to MSG, like cutting down on prepackaged and processed foods and eating more fresh fruits and vegetables. See the sidebar for suggestions on how to minimize potential damage if you do consume MSG.
But if you or your children are struggling with any kind of health issue, whether it’s physical or mental, try eliminating MSG for a while (give it a good three weeks or so) and see if you don’t end up joining the growing number of families for whom MSG is just no longer an option.
How to protect your family from MSG exposure
Eliminating MSG completely is no easy task. Even if you choose to avoid it most of the time, there may be times when you end up eating a meal containing manufactured free glutamates. Unless you are very sensitive, this is no cause for alarm – but there are things you can do to protect your body.
MSG expert Dr. Russell Blaylock suggests “defensive eating” to help alleviate or prevent symptoms brought on by MSG. According to him, the following supplements may help protect against accidental or occasional MSG ingestion:
- Pyruvate – for gut repair and to protect against neuroexcitation
- Magnesium – regulates glutamate uptake
- Antioxidants, such as vitamins E and C
Foods to avoid:
The website MSGTruth.org offers a comprehensive guide for avoiding foods containing MSG and other free glutamates, including label reading tips and MSG content in popular restaurant foods: http://www.msgtruth.org/avoid.htm
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