Monosodium glutamate is a sodium slat of the common amino acid, glutamic acid. Glutamic acid is naturally present not only in our bodies, but in a number of foods, including tomatoes and cheese. A Japanese professor extracted glutamate from seaweed broth and determined that this component provided a savory taste to the soup. In taste-bud terms, glutamate offers an “umami” flavor to food. While MSG was originally made by extracting it from seaweed, it is now produced by the fermentation of starch, sugar beets, sugar cane, or molasses. The fermentation process is similar to that used to make yogurt, wine, and vinegar.

Glutamate functions as a neurotransmitter in the brain, “exciting” the neurons. In 1969, a study was done in which newborn mice were injected with large doses of MSG. The result was harmful neurological effects. Since that time, and because of the concerns about glutamate’s ability to stimulate the brain, there has been an increased concern around the safety of consuming MSG. While large doses of MSG can raise blood levels of glutamate, dietary glutamate should have little to no effect on the brain, as it can’t really cross the blood brain barrier in any significant quantity.

Today, MSG is used greatly in Chinese food as a flavor enhancer. The FDA recognizes it as an additive that is Generally Recognized As Safe (GRAS), and it has been used as a food additive for decades. However, many people report adverse effects after consuming MSG. Some complaints include:

-heart palpitations
-chest pain

Despite these complaints, researchers have found little to no evidence to support a definitive link between MSG and such symptoms. Some studies have found that individuals may have an MSG sensitivity. In these individuals, adverse effects from exposure to MSG have been documented. BUT, even with MSG sensitivity, VERY large doses are required – 3 grams per day, which is about SIX TIMES the average daily intake. A few observational studies have linked MSG consumption to weight gain and obesity, but it’s unclear if such findings are a consequences of MSG consumption or that fact that the foods MSG is typically added to are mostly processed, low-quality foods.

So, what’s the verdict? Well, if you’re looking at it from a purely scientific standpoint, MSG is really pretty harmless. It hasn’t been found to cause any of the negative effects many people claim, but in very high doses, may be problematic to those who have a specific MSG sensitivity. However, if you’re looking at it from a broader, more health-conscious perspective, I’d still highly recommend avoiding it, and here’s why. Yes, MSG/glutamate is a naturally occurring substance found in a wide variety of foods. So is sugar. In an apple, carrots, or any number of other naturally found fruits and veggies, this sugar is a normal part of the food and something our body is made to recognize. Additionally, it comes packaged with a number of other nutrients like fiber, vitamins, and minerals. But, when we isolate it and add straight sugar to foods that wouldn’t naturally have such a compound, our bodies get extra doses of nutrient-poor, calorie-dense sugar bombs, unnecessary for our health or nutrition, and often at the expense of otherwise healthier food options.

The same holds true for MSG. Yes, it occurs naturally in plenty of foods. But now it’s being added to foods that would never have had it. If you’ve followed my posts at all, you know I’m never a proponent of adding unnatural, man-made stuff to our food. From a strictly “less is more” perspective, I would encourage you to eat foods that are in the same form Mother Nature produced them, no additives or “sparkles” necessary. Additionally, as mentioned above, MSG-laden foods tend to be highly processed, nutrient poor foods like soy “meat” products, bottled sauces, salad dressings, canned soup, and things like chips that contains “spices”. Most of these foods are low in nutrition and high in sodium, unhealthy fats, and many non-food additives. In other words? They really shouldn’t be a regular part of your diet anyway. So, is MSG avoidance likely to be the “key” to your health make-over? No. Will avoiding foods that contain MSG help with your health and your weight loss? Probably, but only if it’s because you’re replacing them with nutrient-rich, whole, real foods. Take away message – eat real food.

Aubrey Phelps, MS, RDN