Chinese Restaurant Syndrome. Between truth and fiction

Have you ever been scared by “Chinese restaurant syndrome”? This term refers to a set of symptoms that include nausea, facial flushing, rapid heartbeat, headache, profuse sweating, and numbness of the mouth.

According to some scientists, these symptoms are caused by monosodium glutamate, known as a “flavor enhancer,” which is often used in Chinese cuisine. But over the 40 years of the “syndrome’s” existence, it has become shrouded in many dubious myths. So let’s take an objective look at all the available facts and come to our own conclusion.

In nature, monosodium glutamate is formed from glutamic acid, which is found in virtually all proteins. It is present in freshly harvested vegetables, fresh meat, and poultry, giving them an appetizing natural taste and aroma. During storage and preservation of products, the amount of this amino acid decreases. Thus, the addition of glutamate powder corrects the situation, restoring the lost taste and smell. In addition, the human body contains about 2 kilograms (!) of natural glutamate, without which the body cannot function.

In its pure form, monosodium glutamate looks like a solid white crystalline powder with no taste or smell. Only when added to food does it enhance its taste properties. This is why the flavor enhancer is widely used in the production of sausages, sauces, canned and frozen semi-finished products, potato chips, and many other food products. Therefore, the question is no longer whether or not monosodium glutamate is added to a particular product, but rather how much of this additive is used in a specific dish.

According to scientists’ estimates, the average European consumes between 10 and 20 grams of naturally occurring glutamate daily. An additional 0.3-0.5 grams is consumed in the form of food additives. For residents of East Asia, daily consumption of flavor enhancers can reach 3 grams.

The industrial use of monosodium glutamate originated in Japan, where for centuries an extract from algae rich in glutamic acid was used to improve the taste of food. In 1907, the additive was first obtained in its pure form through fermentation from carbohydrates, and its production was patented by the large Japanese corporation Ajinomoto. The Japanese experience as a nation of long-lived people proved the safety of the seasoning, and since then it has spread rapidly throughout the global food industry. In 1947, the additive officially began to be used in the United States as a flavor enhancer, and soon it was approved as a food additive in Europe as well.

The first reports of painful symptoms resulting from eating foods containing glutamate appeared in the American media in the late 1960s. The term “Chinese restaurant syndrome” was first mentioned in 1968 in a publication in the authoritative medical journal New England Journal of Medicine, where its author, Robert Ho Man Kwok, an American doctor of Korean descent, described symptoms that usually appear 15-20 minutes after eating and last up to two hours, without any serious consequences. However, immediately after eating, numbness may occur in the back of the neck, gradually spreading to both arms and the back, accompanied by general weakness and rapid heartbeat. Dr. Kwok attributed these sensations to the addition of monosodium glutamate to food by Chinese restaurant chefs. With the doctor’s light touch, a flood of similar and more impressive descriptions of similar cases poured into scientific journals, where there was already talk of burning in the chest, nausea, and rapid heartbeat. Sensationalist journalists don’t care what they scare their readers with, whether it’s bird flu, the apocalypse on 12/21/12, or “Chinese restaurant syndrome.”

In the mid-1970s, glutamate was already the subject of serious controversy. American neurophysiologist John Olney discovered that this substance could cause irreversible brain damage in rats. After that, glutamate began to be suspected of causing many diseases, from ordinary headaches to Alzheimer’s disease.

However, other scientific studies have shown the beneficial effects of glutamic acid on the body. There is evidence that it improves memory and helps concentration. The amino acid and its derivative, monosodium glutamate, provide the body with important building blocks that strengthen the nervous system.

Nowadays, glutamate is one of the most researched food additives and, based on the studies conducted, is recognized as completely safe for use as a seasoning.

For more than six centuries, Asian cuisines have been using seaweed extract, the so-called glutamic acid extract, but Chinese people do not suffer from headaches more often than Ukrainians. So why then can eating Chinese food cause headaches, rapid heartbeat, nausea, and a tingling sensation in the throat for some people?

So, the problem is not glutamate, but rather the characteristics of a particular person. Because some of us suffer from a condition called “glutamate intolerance,” which has nothing to do with Chinese cuisine. It turns out that “Chinese restaurant syndrome” is just an allergic reaction in a small percentage of people. But allergies to chocolate, honey, or citrus fruits are not called “syndromes.”