The Origins of a Misguided Controversy
Monosodium glutamate (MSG) is the sodium salt of glutamic acid, an amino acid found naturally in many foods like tomatoes, cheeses, and mushrooms. It was first isolated in 1908 by a Japanese chemist and is prized for its ability to create a savory, or umami, flavor. For decades, MSG was a non-controversial seasoning. However, this changed in 1968 after a letter was published in the New England Journal of Medicine, speculating that MSG was the cause of various symptoms after eating Chinese food. This sparked a flurry of public concern, fueled by flawed studies and, as many historians and researchers note, existing xenophobic biases against Chinese immigrants and cuisine. Later, more rigorous scientific research debunked these initial claims, yet the negative reputation of MSG persisted.
Scientific Consensus: How Much MSG is Considered Safe?
Major health organizations worldwide have extensively reviewed the safety of MSG and concluded it is safe for the vast majority of the population when consumed as part of a normal diet.
- FDA: The U.S. Food and Drug Administration classifies MSG as "Generally Recognized As Safe" (GRAS).
- EFSA: The European Food Safety Authority (EFSA) established an Acceptable Daily Intake (ADI) of 30 mg per kg of body weight per day. This is a level that most people do not approach in their daily consumption. For a 150-pound (approx. 68 kg) person, this translates to about 2 grams per day.
- JECFA: The Joint FAO/WHO Expert Committee on Food Additives has also classified MSG as safe, concluding that it is unlikely for individuals to obtain hazardously high levels from food.
What About the MSG Symptom Complex?
A very small percentage of the population (less than 1%) may report experiencing mild, short-term symptoms, such as headaches, flushing, numbness, or weakness, after consuming large amounts of MSG. These symptoms are known as the MSG symptom complex. Crucially, studies have shown these reactions are typically triggered only by very high doses—around 3 grams or more—consumed on an empty stomach. A typical serving of food with added MSG contains less than 0.5 grams, making such a high-dose reaction unlikely during a normal meal. Furthermore, double-blind studies have often failed to consistently replicate these reactions.
Where is MSG Found?
MSG is not limited to Asian cuisine. It is a natural component of many everyday foods and is also used as an additive in countless processed items to enhance flavor. The body metabolizes naturally occurring glutamate and added MSG in the same way.
Foods Naturally Rich in Glutamate
- Cheeses: Parmesan, Roquefort, and cheddar
- Vegetables: Tomatoes, mushrooms, and soy sauce
- Meats: Beef, chicken, and some shellfish
Foods with Added MSG
- Snack Foods: Chips, crackers, and flavored popcorn
- Processed Meats: Hot dogs, deli meats, and sausages
- Sauces & Condiments: Salad dressings, ketchup, and barbecue sauce
- Soups & Broths: Canned soups and bouillon cubes
- Frozen Meals: Ready-made dinners and packaged meals
MSG vs. Table Salt: A Comparison
Some health organizations suggest MSG can be used as a tool to reduce sodium intake, as it contains significantly less sodium than table salt while still providing a salty, savory flavor profile.
| Feature | MSG (Monosodium Glutamate) | Table Salt (Sodium Chloride) |
|---|---|---|
| Sodium Content | Approximately 12% sodium | Approximately 39% sodium |
| Primary Flavor | Savory (Umami) | Salty |
| Usage | Flavor enhancer that balances and deepens flavors | Adds a purely salty taste |
| Cooking Application | Used in smaller amounts to boost umami | Used primarily for saltiness |
A Note on Processed Foods
It is important to remember that MSG is often found in highly processed foods that are high in fat and sodium. While MSG itself is not the primary health concern in these products, a diet high in processed foods is linked to poor health outcomes. A good strategy is to focus on a balanced diet rich in whole foods, and use additives like MSG in moderation to reduce overall sodium without sacrificing flavor. For more information on food safety regulations, you can refer to authoritative sources like the U.S. Food and Drug Administration (FDA) at https://www.fda.gov/food/food-additives-petitions/questions-and-answers-monosodium-glutamate-msg.
Conclusion
Decades of robust scientific research by major health bodies like the FDA, WHO, and EFSA have affirmed that MSG is a safe food additive for the general population. The amount of MSG considered safe is significantly higher than what is consumed in a typical diet. The enduring fear of MSG is largely rooted in flawed early research and cultural biases rather than modern science. For the small number of individuals who report sensitivity, symptoms are generally mild, temporary, and associated with exceptionally high doses consumed without food. By understanding these facts, consumers can make informed dietary choices and appreciate MSG for what it is: a simple flavor enhancer, not a health threat.
