Monosodium Glutamate is an extraction of glutamic acid in a salt molecule. We all know its use is highly debated, but why exactly are people arguing so much all of a sudden? It's been used for decades, ever since it was discovered by a man in Tokyo after he extracted it from seaweed.
After World War II, MSG was brought over to the US and was produced by extraction. In 1956, Japan figured out how to get it through fermentation & start making a lot of it at once. And as the years progressed, we eventually all started fermenting it from genetically modified bacteria. This allowed mass production of the additive. Very few people pay attention to the way its production has evolved over time and stick to the old argument, "But we've been eating it for over a hundred years.. " forgetting it was just a slow, simple extraction from seaweed back then. Things have changed.
Another thing that has changed is the fact that this isn't the only additive put in foods as a flavor enhancer. And when you start combining chemicals, you get different reactions. Hence, we have people who are allergic to certain foods containing MSG, people who are not, and people who are and aren't, depending on which MSG foods they're eating and how much. It got complicated.
Fortunately, there's a way to enhance the flavor of your food without using it. All you have to do is add a little salt and vinegar to your meal, and the combination works just like MSG.. but on a much safer level. Also, I will point out that when buying products from the supermarket, keep in mind companies have about 20 different names for MSG. So you can buy a can of soup that contains so many different lab varieties of glutamic acid added on top of each other that someone who's sensitive to it can eat half a can and go into anaphylactic shock. This isn't an exaggeration, as it really happened to someone I knew, and he ended up in the emergency room getting pumped full of prescription grade Benadryl.
I'm not here to debate the safety of MSG. I'm just here to tell you what it is, and you can make up your own mind.