Few food ingredients carry the toxic stigma of MSG, also known as monosodium glutamate. But does this food additive deserve its nasty reputation for causing everything from headaches to brain damage? Katharine Woessner, an immunologist and allergist, explains what science tells us about MSG’s effects on health, and food writer Fuchsia Dunlop explains why perceptions of the additive might be different in Asian countries. Read more about how MSG got its reputation.