Why do the foods that taste so delicious have to be so bad for us? Is it too much to ask for Doritos to be good for our eyes, like carrots are (they’re both orange, right?), or for greasy lo mein to boost the human immune system, or for ranch dressing to reduce stress? You already know the answer to that question, but what you might not have thought to ask is why these things are so appetizing in the first place. It’s often because of monosodium glutamate, better known as MSG—a controversial additive lurking in many of our favorite snacks, prepackaged meals, and condiments. It may tantalize your taste buds, but anyone worth her salt should be informed and cautious about this flavor enhancer and its potential health hazards.
Not All Acids Are Created Equal
MSG comes from innocent enough beginnings: it’s a byproduct of glutamic acid, a type of amino acid that occurs naturally in the human body. In its pure form, glutamic acid is easily broken down by our digestive systems and functions as a neurotransmitter. But when food manufacturers take matters into their own hands and deconstruct it themselves, usually by fermenting carbohydrates—starch, corn sugar, or molasses made from sugar beets or cane—glutamic acid becomes a crystalline white substance that’s been called MSG since the Ajinomoto Corporation of Japan patented it in 1909.
Though Chinese food is the first culprit most people point to when identifying carriers of MSG, its presence is actually much more wide-ranging. Since MSG’s introduction to the American market in 1947, it has proliferated throughout the prepared-foods industry, making its way into everything from Campbell’s soup to flavored chips to ramen noodles, bottled gravy, salad dressings, and bouillon cubes. Why is it so prevalent? Because our taste buds can’t get enough of it.
MSG capitalizes on humans’ “fifth taste,” a predilection for savory fare that Japanese chemist Kikunae Ikeda deemed umami in 1908. Glutamic acid is what produces umami flavor, which can be found in tomatoes, parmesan cheese, and meat, among other foods. Furthermore, Spanish scientist Ana San Gabriel, the primary author of a paper published in the July 2009 American Journal of Clinical Nutrition, discovered that certain receptors on the human tongue are activated only by glutamate. That explains why MSG, glutamate in artificial form, is so enticing to countless people, as well as why so many food makers incorporate it into their products—it helps them make millions of dollars.
Fever for the Flavor
The Food and Drug Administration (FDA) includes MSG on its list of GRAS ingredients—“generally recognized as safe”—but “generally” is the operative word here. It may make your Doritos taste cheesier, but if you’re especially sensitive to glutamate, you could be doing your body a great disservice by ingesting MSG. In fact, there’s a name for the battery of negative side effects that the additive induces in some people: MSG symptom complex or, more colloquially, Chinese restaurant syndrome (CRS). The condition got its moniker in 1968, after diners at a Chinese restaurant reported burning, numb, and tight upper-body sensations.
In 1995, an FDA report confirmed that MSG can cause many short-term symptoms (though no conclusive evidence has emerged to link consumption with terminal diseases). According to the Mayo Clinic, signs of CRS may include a burning feeling in your chest, abdomen, shoulders, thighs, forearms, or the back of your neck; facial pressure, tightness, or numbness; chest pain; nausea or vomiting; perspiration; headache; heart palpitations; flushing; or wheezing. While these effects usually pass without requiring treatment, you should contact your doctor if they persist or worsen. But the only way to escape CRS if you believe you’re susceptible is to avoid eating MSG altogether.
A Salt by Any Other Name …
Steering clear of MSG-laden foods is a trickier proposition than you might think. While the FDA requires manufacturers who use MSG to mention it on their products’ labels, many companies sneakily sidestep this requirement by using additives that contain MSG but don’t include the acronym in their names. To be an MSG sleuth, you’ll need to carefully read all the ingredient lists of foods you’re considering buying and keep your eyes peeled for the following items, all of which always contain some MSG:
- Hydrolyzed vegetable protein; hydrolyzed protein; hydrolyzed plant protein
- Plant protein extract
- Sodium caseinate; calcium caseinate
- Yeast extract
- Textured protein
- Autolyzed yeast
- Hydrolyzed oat flour
Also, keep in mind that because the glutamate element in MSG is specifically what causes people’s adverse reactions, some foods that don’t use MSG but do contain other glutamate-based ingredients can be harmful as well. These items include soy extract or soy sauce, modified corn starch, modified food starch, protein isolate, yeast extract, and hydrolyzed soy protein.
You Are What You Eat
The next time you’re contemplating purchasing processed foods in the grocery store, spend a few extra minutes getting acquainted with their labels. You may not be prone to glutamate sensitivity, but any additive that can make someone’s torso feel like it’s on fire is not your friend. Fortunately, the amount of glutamate—especially MSG—that you consume is entirely within your control, as long as you’re willing to commit to being an informed food shopper and diner. Even if you have dinner at your favorite Asian eatery several nights a week, there’s a good chance that the kitchen will make MSG-free dishes for you if you ask. I’d be willing to bet that the cooks there are pretty eager to avoid having Chinese restaurant syndrome strike one of their customers.