Monosodium Glutamate: America’s Favorite Additive
Monosodium glutamate (MSG) is the salt form of glutamic acid, one of the Amino Acids that make up complete proteins. It’s used as an additive in food to enhance flavor and belongs to a class of substances known as excitotoxins. Excitotoxins work by tricking the brain into thinking something tastes good. But being on the salty side, it’s typically in savory foods like ketchup and Doritos – and of course Chinese food. The FDA performed extensive studies on MSG when it was introduced and found that most people metabolize it as a protein. There are other studies that contend that the FDA studies were flawed and that MSG causes temporary brain lesions in laboratory rats. A recent chain email going around claimed that MSG is behind America’s obesity problem – that since scientists use it to fatten mice for obesity studies that perhaps it is having a similar impact on humans.
Some individuals, like myself, have a reaction to MSG. This is considered by the FDA to be rare, with mild and transitory symptoms. Symptoms typically include a headache typically described as one’s “face hurting”, ranging to the more extreme muscle twitching and vomiting. It can trigger an attack for asthma sufferers like my brother. Typically small amounts of MSG are tolerated, but it reportedly can build up in one’s system over the course of a few days to a level that causes a reaction.
The MSG studies available on medical websites do confirm that scientists add MSG to the food of mice to fatten them up. However, there are also studies that demonstrate that mice react differently than humans to MSG and that mouse studies cannot be extrapolated to humans. The idea behind the mouse weight gain is that MSG makes the food more palatable, so the mice eat more and gain weight more rapidly than just with fattening food. There was a conclusion for human studies to the effect that MSG should be investigated for use with geriatric patients to make food more palatable. My own conclusion about the MSG-obesity link is that it’s another case of wishful thinking that something besides eating too much and not exercising is behind the weight gain. My doctor friend scoffs at the idea propounded in the scare email that one could gain weight without consuming more calories than one needs.
However, the increased focus on MSG and other additives has caused some manufacturers to begin either removing it from products or creating MSG-free versions of products. This is a boon to those of us who need to avoid MSG. The information on the web about avoiding MSG says that individuals who have a reaction to it would have a reaction to any form of free glutamic acid. That is, the amino acid split out from its source protein. There is a list of about 75 items to avoid. Here is one of the websites containing a list: http://www.truthinlabeling.org/hiddensources.html . I haven’t personally tested the entire list to see if it makes me ill.
The list includes anything protein enriched (protein isolates), malted barley flour, caragheenan, yeast extract and “natural flavors”. Since MSG is often extracted from seaweed, it is indeed a natural flavor, which means organic products can still include these ingredients. Some foods labeled “no MSG” still contain other forms of free glutamic acid.
The list of ingredients to avoid are in almost all salad dressings, soups, condiments, prepared poultry products, snack crackers, breads, gelatin, canned tuna – getting the picture? The broth injected in your holiday turkey is usually MSG and water. I make most of my own foods from scratch and am a diligent label reader. The simple approach is to look at low sodium versions of foods or not to buy prepared foods that have a long list of ingredients. Eating out, the safest course is to eat spicy ethnic or at expensive restaurants. I’ve never had an issue with Indian or Mexican food (not counting Taco Bell). Avoiding MSG at a deli is nearly impossible. Fast food restaurants at least post their menus online, so one can check the ingredients ahead of time. Thai and Chinese food usually contains MSG, but except for buffets, can almost always be prepared without it. And unlike American restaurants, they prepare the food fresh instead of pulling it ready-made from a freezer, so know what’s in it. Basically, for those who don’t become ill from MSG and it’s relatives, it’s probably more trouble than it’s worth to avoid it.