Brief overview
- Causes: Experts discuss the flavor enhancer glutamate (monosodium glutamate) as a trigger. However, there is no scientific evidence to date.
- Risk factors: For those affected, Asian food and other industrially produced ready-to-eat foods added with flavor enhancers are a risk.
- Symptoms: From headaches and aching limbs, dizziness and sweating to tingling and rashes, heart palpitations and chest tightness.
- Treatment: No known treatment options
- Prognosis: No accurate prognosis possible, symptoms often change over time in affected individuals
- Prevention: Avoid foods containing glutamate if sensitivity is known.
What is Chinese restaurant syndrome?
The Chinese Restaurant Syndrome was first described in 1968, when a doctor in the USA suddenly noticed strange symptoms in himself after a visit to a Chinese restaurant and published his discovery.
This is the reason for the synonymous term “glutamate intolerance”, which is often used for the Chinese restaurant syndrome. A direct connection between glutamate consumption and Chinese restaurant syndrome could not be proven by any study so far. However, it is possible that there are people who react more sensitively to glutamate.
Glutamate – a jack of all trades
Physiologically, the umami taste helps the body recognize protein-rich foods. Apart from glutamate, there are only a few other substances that taste “umami” such as aspartates, salts of aspartic acid.
In Central Europe, people consume around ten to twenty grams of natural glutamate per day. Glutamate is predominantly bound to proteins in foods. This bound glutamate accounts for most of the daily intake. Only about one gram of the average daily intake is available in natural foods as non-bound, but free glutamate.
Glutamate is approved as a safe food additive throughout the EU (with the E designations E620 to E 625). It is officially considered a “seasoning”. A maximum permitted amount is not defined. Europeans consume an average of 0.3 to 0.6 grams of additional free glutamate as a flavor enhancer per day with their food, while people in Asia consume about 1.7 grams.
Chinese restaurant syndrome: symptoms
Children usually show other symptoms such as tremors, cold symptoms, irritability, crying and febrile delirium. Monosodium glutamate has also been reported to cause hives and swelling of the face (angioedema, Quinke’s edema).
Chinese restaurant syndrome and asthma
Overall, the symptoms of Chinese restaurant syndrome are reminiscent of an allergic reaction. However, since it is not an allergy, experts refer to it as a so-called pseudoallergic reaction.
Causes and risk factors
Chinese restaurant syndrome has attracted a lot of attention since it was first described. However, a glutamate allergy could not be proven in a study involving 130 sufferers with self-diagnosed Chinese restaurant syndrome.
Many people who report so-called Chinese restaurant syndrome do not interpret their complaints correctly. Usually, triggers other than glutamate are behind it, for example histamine or a high fat and/or sodium content. It is also possible that such symptoms are triggered by the interaction or interaction with glutamate.
Glutamate classified as harmless
Since studies have so far provided no evidence of a causal link between the consumption of monosodium glutamate and Chinese restaurant syndrome, it has been classified as safe for health by health authorities.
Since then, monosodium glutamate has been industrially produced in large quantities and used as an additional seasoning in food, especially in Asian food.
How is Chinese restaurant syndrome diagnosed?
If Chinese restaurant syndrome is suspected, affected individuals should consult a general practitioner, also to rule out an allergic reaction to other foods. A detailed medical history, a physical examination and an allergy test are helpful for the doctor to make the correct diagnosis. Possible questions the doctor may ask include:
- Do you have any allergies? For example, do you suffer from hay fever?
- Do the symptoms always occur in connection with certain foods?
- Do you take any medications? If yes, which ones?
- Do you suffer from psychological stress such as stress, depressive moods or physical stress (e.g. due to intensive sports)?
- Do the symptoms occur in unfamiliar surroundings, such as the outdoors or in homes with pets?
For this purpose, the doctor often performs a skin test on the forearm or back, a so-called prick test. A blood sample can be taken to detect antibodies against certain allergens. If the connection between the symptoms that occur is unclear, a symptom diary, for example, is helpful.
What helps against the Chinese restaurant syndrome?
There is no special therapy against the Chinese restaurant syndrome, except for the avoidance therapy: Affected persons who believe they suffer from the Chinese restaurant syndrome should avoid corresponding foods. Patients avoid Chinese soups or seasoning sauces, as these contain particularly high levels of glutamate.
Prevention
How do you recognize foods containing glutamate? All processed, packaged foods have an ingredient list that lists all ingredients in order of quantity. So it’s worth taking a look at the ingredients list: every food additive approved in the EU has an E number. It is identical in all member states. Glutamate is hidden behind the E numbers E620 to 625.
In addition, those affected with known complaints should avoid eating foods containing glutamate, such as Asian food, as a precaution. It is possible that another food allergy is behind the symptoms. Therefore, anyone who shows symptoms after eating a certain food would do well to avoid this food in the future.
