Well, I did not check my sources with the internet, but I'm sure you can find the studies through medical journals. Or, even easier, check with your nutritionist and endocrinologist - which is how I first heard of them back when I was diagnosed with diabetes. Of course, after reading your note, I had to google too, and here are the
first two results that I got. Neither source is what I would call non-credible, though there were plenty of others in the 484,000 hits were cause for giggles. So...research is out there. I'd love to read the rest of this
one. Now, it does not say specifically MSG, but glutamate is the G in MSG and the MS is mono-sodium. It breaks down to one sodium and glutamates. Of course, research is still on-going, but it has been out there for a very long time.
I'm trying to think of a good analogy. Okay, it is like saying that a spoon of sugar is actually ice cream. The sugar is a part of the ice cream, like an amino acid is a part of a protein; but sugar is not ice cream and amino acids are not proteins. Proteins are macro-molecules and an amino acid is an itty-bitty thing by comparison...though...when I had to memorize their entire structures I would not have called them itty or bitty. However, now that the nightmares have ended, I'll go with that.
When you look at the reactions that people tend to have with MSG, (feeling unwell, headaches, etc.), it seems to fall in line with the sensitivity classification which is what it would be based on its chemistry.