Deciphering the Science of MSG
Monosodium glutamate (MSG) is the sodium salt of glutamic acid, a naturally occurring amino acid found in many foods. MSG has a savory flavor known as umami, which is considered the fifth basic taste. It is often added to processed foods, sauces, soups, and restaurant meals to enhance and balance flavor. The controversy surrounding MSG originated from anecdotal reports in the late 1960s, but extensive scientific research since then has affirmed its safety.
Official Stances from Health Organizations
Multiple global health authorities have evaluated MSG and concluded that it poses no health threat to the general population at typical consumption levels. The body processes added glutamate in MSG the same way it handles the glutamate found naturally in food.
- US Food and Drug Administration (FDA): The FDA classifies MSG as "Generally Recognized As Safe" (GRAS), placing it in the same category as common ingredients like salt and pepper. The FDA acknowledges some reports of mild, temporary symptoms in sensitive individuals but has not been able to consistently confirm a causal link.
- World Health Organization (WHO) and JECFA: The Joint FAO/WHO Expert Committee on Food Additives (JECFA) has confirmed MSG's safety multiple times, placing it in the safest category with an "Acceptable Daily Intake (ADI) not specified". This reflects its very low toxicity and common use levels.
- European Food Safety Authority (EFSA): In 2017, the EFSA established a group ADI of 30 mg/kg of body weight per day for glutamates. However, the EFSA noted that some population groups might exceed this ADI, leading to a recommendation to revise maximum permitted levels. This ADI is based on animal studies and remains significantly higher than average consumption.
The Real Context of MSG Consumption
An average daily intake of MSG from food additives is estimated to be very low, around 0.55 grams in some Western countries. This is a fraction of the average 13 grams of naturally occurring glutamate consumed daily from protein-rich foods. The threshold dose that triggers mild, short-lived symptoms in sensitive individuals is typically 3 grams or more, often on an empty stomach. It is extremely unlikely for most people to consume this much at one time through a typical meal.
Understanding MSG Symptom Complex
For the small subset of people who report adverse reactions to MSG, the symptoms are now called "MSG symptom complex" rather than the outdated and xenophobic term "Chinese Restaurant Syndrome". The symptoms are usually mild and temporary, and there is no evidence of a long-term health impact. Factors other than MSG, such as high sodium content or other ingredients in highly processed foods, may also contribute to these feelings.
Common symptoms of MSG symptom complex include:
- Headache
- Flushing or sweating
- Numbness or tingling
- Heart palpitations or chest pain
- Weakness or fatigue
- Nausea
- Facial pressure
MSG and Sodium Reduction
Contrary to popular belief, MSG contains significantly less sodium than table salt. MSG is about one-third sodium by weight, while table salt is about 39% sodium. This means MSG can be a useful tool for reducing total sodium intake without sacrificing flavor. This is particularly beneficial for those on low-sodium diets who want to enhance the palatability of their food.
| Comparison of MSG and Table Salt | Feature | MSG | Table Salt (NaCl) |
|---|---|---|---|
| Function | Enhances umami (savory) flavor | Primarily adds salty flavor | |
| Sodium Content | Approximately 12% sodium | Approximately 39% sodium | |
| Flavor Impact | Boosts existing savory notes | Provides strong saltiness | |
| Palatability | Self-limiting; too much tastes bad | Can be easily overused | |
| Sodium Reduction | Can reduce total sodium in recipes | Adds significant sodium content |
The Importance of Context in Research
Many of the studies that generated fear around MSG were poorly designed, using flawed methods like high-dose injections rather than oral consumption, or failing to use adequate control groups. In typical dietary context, MSG is well-metabolized by the gut and has a minimal effect on systemic processes. Critics have also pointed out that negative associations in some animal studies, often conducted with massive doses, are not relevant to human dietary intake. The scientific consensus remains that MSG is safe for most individuals when used as a flavor enhancer in food.
Conclusion
For the vast majority of the population, there is no need to worry about limiting how many MSG per day is consumed. International health organizations have extensively studied MSG and deemed it safe for consumption at normal dietary levels, with average intake well below any potential thresholds for temporary side effects. The few who may experience mild sensitivity can identify this and consume it in smaller amounts. As a tool for flavor enhancement and sodium reduction, MSG holds a beneficial place in modern cooking, and its negative reputation is largely based on outdated and flawed information.
