[baak]

Cubans consume a ton of MSG (sazón) and live notoriously long lives despite very poor living conditions.

Your last sentence is very troubling: You feel the negative effects when eating certain foods that you 'suspect' contain MSG. To me, that really sounds like you may psyche yourself out. ie. that you worry about MSG so much that it starts to cause you stress about it, and it's a self-fulfilling prophecy/placebo effect/whatever. Anyway, I can't tell you with 100% certainty that MSG is healthy or not, but I can tell you that there are cultures that consume it in large quantities that seem largely unaffected.

[goatslacker]

The Goya brands definitely do as a flavor additive, but there are other brands of Sazon that don't include any glutamate. Then again, Goya has always been the cheap/crap brand of Spanish food.

[baak]

Badia adds it as well. I'm not just referring to here in the US though. I have a copy of Nitza Villapol's La Cocina Criolla, and almost every recipe calls for MSG.