In 1968, an editorial in the New England Journal of Medicine wondered if eating food in American Chinese food restaurants caused feelings of numbness and fatigue. Decades of research has shown little consensus on whether consumption of MSG is bad for us. How the MSG myth was born and propagated:

“‘The Chinese food causes thirst,’ he wrote, ‘which would also be due to the high sodium content. The syndrome may therefore be due merely to the large quantity of salt in the food.’ MSG was almost an afterthought: ‘Others have suggested it may be caused by the monosodium glutamate seasoning used to a great extent for seasoning in Chinese restaurants.’ He closed ruminating on the idea that the presence of MSG might make the sodium-related symptoms ‘more acute.’

“But it was the MSG bit that people focused on. The New York Times quickly followed the NEJM’s lead, publishing a small write-up on the issue a month later (Chinese Restaurant Syndrome Puzzles Doctors,’ May 19, 1968). Also fueling the burgeoning myth was a latent distrust of what happened behind the kitchen door at Chinese restaurants, even as they became increasingly common to American diners in the late 1960s. ‘To be suspicious of the goings on in the kitchen of a Chinese restaurant was not uncommon,’ food historian Ian Mosby writes in his paper ‘”That Won-Ton Soup Headache”: The Chinese Restaurant Syndrome, MSG and the Making of American Food, 1968–1980.’ For many, suspicions of mysterious meats and other ‘excessive’ practices were still present.”