The debate over MSG began with a letter to the editor in the 1960s. For over half a century, monosodium glutamate (MSG) has been blamed for symptoms like headache, indigestion, feeling flushed, and acid reflux, especially in Chinese restaurants. But is MSG really harmful?
According to the U.S. Food and Drug Administration (FDA), MSG is safe. A 1995 FDA-commissioned study confirmed this, noting only mild, short-term symptoms like headache, flushing, or drowsiness in some individuals who consumed large amounts (3 grams or more) without food. However, a typical serving contains less than 0.5 grams of MSG.
The fear around MSG stems from a 1968 letter to the New England Journal of Medicine by Dr. Robert Ho Man Kwok, who described symptoms like numbness, weakness, and heart racing after eating Northern Chinese food. He suggested salt, cooking wine, or MSG as possible causes, coining the term “Chinese Restaurant Syndrome.”
MSG, isolated and patented by Japanese chemist Kikunae Ikeda in the early 1900s, became a common additive in East Asian cooking and later in the U.S. By the time of Kwok’s letter, MSG was widespread in processed, packaged, and restaurant-prepared foods.
Despite initial responses to Kwok’s letter describing various symptoms, later studies attempting to establish “Chinese Restaurant Syndrome” as a condition driven by MSG were poorly executed and biased. Some early trials gave volunteers with known reactions to Chinese food wonton soup to see if they would react again, leading to expected results. Other studies injected MSG into mice in large doses, linking it to brain lesions and obesity—conditions irrelevant to typical human consumption.
As faulty studies and media hysteria amplified the fear of MSG, public perception cemented. Chinese restaurants posted “No MSG” signs, and food manufacturers labeled their products accordingly. Even today, Yelp reviews mention MSG-induced symptoms, despite widespread debunking of the phenomenon.
Fast food and snacks, often high in MSG, don’t face the same complaints as Chinese food. Foods like tomatoes, mushrooms, and Parmesan cheese naturally contain MSG without sparking similar fears. This stigma around MSG and Chinese food exemplifies the “nocebo” effect, where negative expectations lead to real symptoms.
While MSG could be a headache trigger, many studies used doses much higher than normal consumption. Clinical trials show conflicting results, and MSG’s role in causing migraines remains unclear. Like other ingredients such as alcohol, dairy, or eggs, MSG is safe for most people but may trigger headaches in some. However, many believe MSG is a problem when it’s not.
