Scientists who have performed controlled measurements on peoples reactions to MSG.
As usual in human experience, without having specialized knowledge obtained via controlled, repeatable measurements, it is wildly difficult to accurately observe an informational correlation between two out of the literally millions of influential events on your body. Your conviction that MSG causes headaches and nausea is directly analogous to people who are convinced that proximity to arbitrary electromagnetic fields causes acute physical distress. This is standard confirmation bias. We all do it, it's a natural consequence of our brains' imprecise pattern matching combined with the extremely limited perspective any individual human has. The reliable way to mitigate this human flaw is to perform good science.
The parts of humanity involved in figuring it out, and those laymen which have bothered to follow along. I'm in the latter group, so yes, feel free to ignore me. (Just don't ignore the actual research, eh?)
LeVar Burton: you don't have to take my word for it!
As usual in human experience, without having specialized knowledge obtained via controlled, repeatable measurements, it is wildly difficult to accurately observe an informational correlation between two out of the literally millions of influential events on your body. Your conviction that MSG causes headaches and nausea is directly analogous to people who are convinced that proximity to arbitrary electromagnetic fields causes acute physical distress. This is standard confirmation bias. We all do it, it's a natural consequence of our brains' imprecise pattern matching combined with the extremely limited perspective any individual human has. The reliable way to mitigate this human flaw is to perform good science.