This article is both accurate and highly misleading. The author is correct that there is very little reliable evidence that links glutamic acid and/or glutamate to health problems. The backlash against MSG as a result of the "Chinese Restaurant Syndrome" craze, was not rooted in scientific inquiry.
However, MSG is not just a source for glutamate like seaweed and tomatoes are. MSG is the sodium salt of glutamic acid and contains not just glutamate but also sodium ions. Having 2000mg of natural glutamate should be harmless. Having enough MSG to give you 2000mg of glutamate means you're getting a shit ton of sodium. That's not good for you, especially if you're one of the many people for whom excess sodium intake adversely affects your blood pressure. So while MSG is presumably no worse than NaCl (and is perhaps better in that the umami flavor means you don't have to use as much sodium to get an equally rich taste), to say that MSG is totally harmless without even mentioning sodium and hypertension is ridiculous. Even in terms of short term effects, I've had plenty of MSG-free hot and sour soups that made my head itch. Not from MSG but from thousands of mg of sodium found in their gratuitously added soy sauce and table salt.
However, MSG is not just a source for glutamate like seaweed and tomatoes are. MSG is the sodium salt of glutamic acid and contains not just glutamate but also sodium ions. Having 2000mg of natural glutamate should be harmless. Having enough MSG to give you 2000mg of glutamate means you're getting a shit ton of sodium. That's not good for you, especially if you're one of the many people for whom excess sodium intake adversely affects your blood pressure. So while MSG is presumably no worse than NaCl (and is perhaps better in that the umami flavor means you don't have to use as much sodium to get an equally rich taste), to say that MSG is totally harmless without even mentioning sodium and hypertension is ridiculous. Even in terms of short term effects, I've had plenty of MSG-free hot and sour soups that made my head itch. Not from MSG but from thousands of mg of sodium found in their gratuitously added soy sauce and table salt.