Why Is MSG Bad For You?
MSG stands for monosodium glutamate and is an food additive that, many years ago, got significant press about how bad it was for you. As it turns out, many Asian cuisine flavor enhancing ingredients contained high amounts of MSG but it wasn’t commercial separated and made into its own individual product until 1907 and introduced in the US in 1947. MSG was and is still used as a flavor enhancer in many foods, especially processed foods such as canned soups, frozen dinners, and fast food.
So why is MSG bad for you?
First off, it’s actually the glutamic acid in the MSG that is of concern for most people and in 1959 the FDA classified MSG as “generally recognized as safe.” However, because glutamate is absorbed very quickly in the gastointestinal tract it can spike blood plasma levels of glutamate. What does this mean for you? Well, glutamic acid is known as an excitotoxins and high levels of excitotoxins has been shown in animal studies to cause damage to areas of the brain. Does this happen in people? No one knows, but it’s been shown in mice.
Indirectly, MSG has been shown in lab tests to downregulate hypothalamic appetite supression, which is a fancy word for it makes you feel hungry again. That’s the whole joke about how you feel hungry thirty minutes after you eat at a Chinese restaurant. The indirect effect is that the mice in the lab just kept eating and thus got fatter. However, a 1973 study didn’t show a similar effect in human beings.
So it’s okay?
The FDA considers it safe but regulations require the clear labeling of MSG on any product that contains it or a product of it. There are no studies that show it’s bad for human beings but it hasn’t been good for mice.
The verdict? You can eat it, but I wouldn’t eat too much of it. And stop it with the Chinese food jokes. 
