For anyone wondering, yes.,it's purely due to racism. Some people made a fake study and letter in 1968 about a guy saying he'd been getting evidence of people who had headaches after eating Chinese food as part of a bet he could get anecdotal evidence accepted in a prestigious journal. Tons of people wrote back to him expressing that they too have the same, He chose MSG and Chinese food purely because he knew his fellow Americans would be more likely to believe ill of China, which was an enemy of the US at the time.

MSG has been studied extensively over the last few decades and is completely safe, and has been proven so countless times. It's also not purely used in Chinese food and even naturally occurs in a lot of foods and is essentially unavoidable. It's a glutamic acid so it's in practically everything.

Thinking about it though I suppose in the 60s, Chinese food might have caused you headaches because from what I've seen, being properly hydrated was very uncommon then with everyone openly drinking far more than nowadays, and some extra salt might dehydrate you more and give you a headache. But that would probably occur with most food, to be honest. Doubly so if you were continuing to drink alcohol with your meal. I was born in the 90s and the difference from even then is night and day. I remember going through an entire school day of 8 hours on whatever I drank at home, one capri sun at lunch and that was it. Hot summer days, you might be permitted to go get a tiny glass of water from the sink, using the plastic cup that was chained to the wall for the whole class to use, that I'm pretty sure never got cleaned once. Nowadays my younger brother of 10 goes into school with two litres of squash and a can of soda for lunch. And I have to say, I don't get nearly as many headaches as when I was a kid. It's not Chinese food's fault though