Hot dog headache; Glutamate-induced asthma; MSG (monosodium glutamate) syndrome; Chinese restaurant syndrome; Kwok's syndrome
MSG symptom complex is a set of symptoms associated with eating food with the additive monosodium glutamate (MSG). MSG is the sodium salt a common amino acid, glutamic acid. MSG is found naturally in our bodies and in many foods including cheese and tomatoes. MSG is added to many different types of foods as a flavor enhancer.
Allergic reaction can be provoked by skin contact with poison plants, chemicals and animal scratches, as well as by insect stings. Ingesting or inhaling substances like pollen, animal dander, molds and mildew, dust, nuts and shellfish, may also cause allergic reaction. Medications such as penicillin and other antibiotics are also to be taken with care, to assure an allergic reflex is not triggered.
Causes
Reports of reactions to MSG originated in 1968 in a letter published in the New England Journal of Medicine. Since then, reports of reactions to MSG have come from people claiming to experience symptoms after consuming food containing MSG. However, studies on MSG in foods have failed to find a conclusive link between MSG and the symptoms some people describe.
The US Food and Drug Administration (FDA) did a study of the issue and found no evidence that MSG in food caused symptoms. The report did find minor reactions in people who consumed 3 or more grams of MSG alone without food. Most foods with MSG have less than 0.5 grams of the additive.
MSG is rated as "generally considered safe" by the FDA.
Symptoms
Exams and Tests
There are no tests for MSG symptom complex.
Treatment
Most symptoms are mild, such as headache or flushing, and need no treatment.
Outlook (Prognosis)
Most people recover from perceived MSG symptom complex without treatment and have no lasting problems.
When to Contact a Medical Professional
Get emergency medical help right away if you have signs of a possible allergic reaction:
- Chest pain
- Heart palpitations
- Shortness of breath
- Swelling of the lips or throat
References
Aronson JK. Monosodium glutamate. In: Aronson JK, ed. Meyler's Side Effects of Drugs. 16th ed. Waltham, MA: Elsevier; 2016:1103-1104.
Bush RK, Baumert JL, Taylor SL. Reactions to food and drug additives. In: Burks AW, Holgate ST, O'Hehir RE, et al. eds. Middleton's Allergy: Principles and Practice. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 80.
US Food and Drug Administration website. Questions and answers on monosodium glutamate.
Version Info
Last reviewed on: 5/23/2022
Reviewed by: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
I am an expert in the field of food additives, particularly monosodium glutamate (MSG) and its associated symptoms, commonly known as the MSG symptom complex. My depth of knowledge is derived from a comprehensive understanding of the scientific literature, medical studies, and regulatory information available up to my last knowledge update in January 2022.
The MSG symptom complex is a collection of symptoms linked to the consumption of foods containing the additive MSG. MSG is the sodium salt of glutamic acid, a common amino acid found naturally in our bodies and various foods, including cheese and tomatoes. As a flavor enhancer, MSG is added to a wide range of foods to enhance taste.
Reports of reactions to MSG date back to 1968, originating from a letter published in the New England Journal of Medicine. Subsequent claims of symptoms after MSG consumption have been made by individuals, but studies examining MSG in foods have failed to establish a definitive connection between MSG and the reported symptoms. Notably, the US Food and Drug Administration (FDA) conducted a study that found no evidence linking MSG in food to the described symptoms. However, minor reactions were observed in individuals consuming high doses of pure MSG without food.
Symptoms associated with the MSG symptom complex, if they occur, are generally mild and temporary, including flushing, headache, muscle aches, numbness or burning around the mouth, heart palpitations, tingling, and drowsiness.
It's crucial to note that there are no specific tests for diagnosing the MSG symptom complex. Most symptoms are mild and do not require treatment, with individuals recovering without lasting problems. The FDA classifies MSG as "generally considered safe."
In case of a possible allergic reaction, characterized by chest pain, heart palpitations, shortness of breath, or swelling of the lips or throat, emergency medical assistance should be sought immediately.
References supporting this information include Meyler's Side Effects of Drugs, Middleton's Allergy: Principles and Practice, and the US Food and Drug Administration website.
This overview aims to provide a comprehensive understanding of the MSG symptom complex, backed by scientific references and regulatory insights up to my last knowledge update in January 2022.
