The LD₅₀ (Lethal Dose, 50%) values for monosodium glutamate (MSG) and sodium chloride (NaCl, table salt) have been studied in animal models, primarily rodents. Below is a comparison based on research findings:
1. LD₅₀ of Monosodium Glutamate (MSG)
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Oral LD₅₀ (rats): 15,000 – 18,000 mg/kg
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Studies indicate that extremely high doses are required to cause acute toxicity.
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Source: Walker, R., & Lupien, J. R. (2000). “The Safety Evaluation of Monosodium Glutamate.” Journal of Nutrition, 130(4), 1049S–1052S.
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Subcutaneous LD₅₀ (mice): 6,000 mg/kg
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Higher toxicity when injected rather than ingested.
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Interpretation:
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MSG has low acute toxicity when consumed orally.
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The FDA and WHO classify it as safe for human consumption at normal dietary levels.
2. LD₅₀ of Sodium Chloride (NaCl, Table Salt)
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Oral LD₅₀ (rats): 3,000 mg/kg
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Salt is more acutely toxic than MSG in high doses.
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Source: European Food Safety Authority (EFSA) (2005). “Opinion on Sodium Chloride.”
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Subcutaneous LD₅₀ (mice): 4,000 mg/kg
Interpretation:
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NaCl is more toxic than MSG in acute overdose scenarios.
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Death from salt poisoning usually results from hypernatremia (excessive sodium in blood).
3. Comparison Table
| Substance | Oral LD₅₀ (Rats) | Subcutaneous LD₅₀ (Mice) | Relative Toxicity |
|---|---|---|---|
| MSG | 15,000–18,000 mg/kg | 6,000 mg/kg | Less toxic |
| NaCl | 3,000 mg/kg | 4,000 mg/kg | More toxic |
4. Human Context
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MSG:
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A 70 kg adult would need to ingest ~1 kg of pure MSG to reach a potentially lethal dose (unrealistic in normal diets).
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Salt:
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~200 g of salt could be lethal for a 70 kg adult (though vomiting usually prevents fatal intake).
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Conclusion:
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Salt is significantly more toxic than MSG in acute exposure.
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Both are safe at normal dietary levels, but excessive salt poses a higher immediate risk.
The negative perception of monosodium glutamate (MSG) has persisted for decades, despite scientific consensus that it is safe for most people. The origins of this bad press can be traced to a mix of racism, flawed science, media sensationalism, and corporate interests. Here’s a breakdown of who and what fueled the MSG scare:
1. The “Chinese Restaurant Syndrome” Myth (1968)
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Origins: The anti-MSG movement began with a 1968 letter published in The New England Journal of Medicine by Dr. Robert Ho Man Kwok, who claimed he experienced numbness, weakness, and palpitations after eating Chinese food.
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Flawed Science: Kwok’s anecdotal report lacked controlled studies, but the media ran with the idea of “MSG sensitivity.”
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Racial Undertones: The term “Chinese Restaurant Syndrome” reinforced xenophobic stereotypes, associating MSG with “foreign” and “unhealthy” food.
📌 Key Study Debunking It:
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A 1993 double-blind, placebo-controlled study (Journal of Allergy and Clinical Immunology) found no link between MSG and the reported symptoms in self-proclaimed “MSG-sensitive” individuals.
2. Media Sensationalism & Pop Culture
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60 Minutes & Other Outlets: In the 1980s–90s, TV shows and newspapers amplified fear without scientific backing.
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Hollywood Influence: Movies and TV often depicted MSG as a dangerous chemical (e.g., The X-Files episode “Squeeze” villainized MSG as a toxic additive).
3. Corporate Interests & Competition
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Natural Food Industry: Companies selling “organic” or “clean-label” products had a financial incentive to demonize MSG as an “artificial chemical.”
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Competitors to Ajinomoto (MSG Producer): Some food companies promoted “No MSG” labels as a marketing tactic, even though their products contained hidden glutamate sources (e.g., hydrolyzed vegetable protein, yeast extract).
📌 Example: Campbell’s Soup removed MSG in the 1990s due to public pressure but replaced it with yeast extract (which contains natural glutamate).
4. Misinterpreted Animal Studies
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“Excitotoxicity” Fear: Some rodent studies in the 1960s–70s showed brain damage from extremely high doses of MSG injected directly into the bloodstream—not relevant to normal dietary intake.
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Ignoring Human Metabolism: Humans metabolize glutamate efficiently, and the blood-brain barrier prevents excessive glutamate from entering the brain.
📌 FDA & WHO Stance:
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FDA: Classifies MSG as GRAS (Generally Recognized as Safe).
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WHO/FAO: Sets no strict ADI (Acceptable Daily Intake) because normal consumption is harmless.
5. Who Benefits from the MSG Scare?
| Group | Motive |
|---|---|
| “Natural” Food Companies | Profit from “No MSG” labels. |
| Media Outlets | Clicks & views from fear-based stories. |
| Alternative Health Industry | Sells detox myths & anti-MSG supplements. |
| Xenophobic Narratives | Targets Asian cuisine as “unhealthy.” |
6. Why Does the Myth Persist?
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Confirmation Bias: People who believe MSG harms them may attribute unrelated symptoms (e.g., overeating, alcohol, stress) to it.
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Placebo/Nocebo Effect: If someone expects MSG to cause headaches, they might experience them even if given a placebo.
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Lack of Updated Public Education: Many still don’t know that tomatoes, Parmesan cheese, and mushrooms contain natural glutamate.
Conclusion: Who’s Behind the Bad Press?
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Primary Culprits: Media fearmongering, corporate marketing, and racial bias.
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Science Says: MSG is no worse than salt—and may even help reduce sodium intake by enhancing flavor.
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