MSG is harmful to health
Monosodium glutamate (MSG) is classified as generally recognized as safe (GRAS) by the FDA and major food safety agencies worldwide. A systematic review of clinical and preclinical evidence found that many alleged harmful effects were based on methodologically flawed studies using excessive doses not representative of dietary exposure.
What we know
MSG is a sodium salt of glutamic acid, an amino acid naturally present in many foods including tomatoes, parmesan cheese, and mushrooms. It has been used as a flavor enhancer for over a century and is one of the most studied food additives in history. The FDA classifies it as GRAS (Generally Recognized As Safe).
The popular concern about MSG began largely from a 1968 letter to the New England Journal of Medicine describing 'Chinese restaurant syndrome' - symptoms such as headache, flushing, and sweating attributed to MSG consumption in Chinese food. However, double-blind placebo-controlled trials have consistently failed to demonstrate a reliable causal relationship between MSG consumption and these symptoms, even in people who believed themselves to be sensitive to it.
A comprehensive 2019 review in Comprehensive Reviews in Food Science and Food Safety examined the full body of preclinical and clinical research and found that many studies showing negative effects used doses far exceeding normal dietary intake and had significant methodological flaws. Clinical trials have not supported links between MSG and the headaches, obesity, or neurotoxicity claimed in popular discourse. EFSA, the FDA, and the WHO all consider MSG safe at levels typical in food.
The myth of MSG harmfulness has also had significant ethnic bias dimensions, as it was primarily associated with Chinese cuisine while identical amounts of glutamate in other foods (such as Italian food using parmesan) attracted no similar concern.
Common claims
- MSG causes headaches, flushing, and Chinese restaurant syndromeNot confirmed by double-blind trials
- MSG is a dangerous neurotoxinDoses in studies were far above dietary levels
- FDA and food safety agencies consider MSG unsafeFalse - MSG is classified as GRAS
- Natural glutamate in food is different from MSGChemically identical; body cannot distinguish them
Evidence hierarchy
All sources
- A review of the alleged health hazards of monosodium glutamateComprehensive Reviews in Food Science and Food Safety / PMC · 2019
- Dietitians say there is no scientific evidence MSG is bad for youUniversity of Illinois Urbana-Champaign · 2020
- A review of alleged health hazards of MSG (PubMed)PubMed · 2019