It's safer to eat as much MSG every day

health

      Zhong kai, deputy director of the youth committee of the Chinese food science and technology association

      Glutamate is a common amino acid, commonly known as monosodium glutamate.       The human body can synthesize glutamate, and it can also be obtained from food. In July 2017, the European food safety authority issued the latest assessment report, glutamic acid and glutamine, monosodium glutamate, glutamic acid potassium magnesium, calcium glutamic acid, glutamate) safe intake is adjusted for 30 mg per kilogram of body weight. They also recommend that the eu's governing body should tighten restrictions on food, which could be the biggest challenge to MSG in 30 years.

The former life of MSG

      At the beginning of the 19th century, the Japanese were inspired by the fresh smell of seaweed, and the extraction of glutamate was the result of a leap in the history of human food. In the 1820s, Chinese chemist wu yunchu invented the technique of hydrolysis to produce glutamate, which he called "MSG" as the difference between "taste" and "taste". After world war ii, Japanese microbiologists invented a new process for using the bacteria to ferment molasses to get glutamate, a process that has been continuously optimized to date. With its good taste and low price, MSG has conquered the food industry and catering industry, and has been enduring for decades.

      An average adult consumes about 13 grams of glutamate per day from food protein, while about 0.5 grams is ingested from MSG. From this point of view, the safety of MSG as a food additive is not too bad. So far, there have been numerous studies on the acute toxicity, subacute toxicity, chronic toxicity, reproductive toxicity or genetic toxicity of MSG, but no specific adverse effects have been found.

      The food and drug administration (FDA) in the middle of the 20th century put MSG in the "GRAS" list, which is fairly safe. It was later assessed that the safety of MSG was guaranteed under normal consumption. Scientific evidence that artificial production of monosodium glutamate and natural monosodium glutamate on the metabolism and physiological and no difference, so the FDA regulation, contain the food of natural sodium glutamate (such as tomato sauce), and shall not be marked "do not contain monosodium glutamate" or "no MSG".

      The world health organization's JECFA (JECFA) respectively in 1970 and 1970 to evaluate the safety of glutamic acid and its salts, set up 120 milligrams per kilogram of body weight safe intake. In 1987, after the JECFA reassessed, the security intake was changed to "no limit", which could be used freely. In 2004, JECFA assessed the safety of glutamate and maintained its previous judgment.

      MSG is widely used worldwide and is considered one of the safest food additives. East Asia is the region with the most monosodium glutamate production and the largest consumption of MSG, with about 2 million tons of global monosodium glutamate, half of which are from China. In the European Union, the upper limit for adding MSG to food is usually 10 grams per kilogram of food, with no limits on the amount of added flavoring. In the United States and China, the use of MSG is not limited and glutamate can be used as a separate spice. In Australia, New Zealand, Japan and other countries, as well as Hong Kong, Macao and Taiwan, the use of MSG is also unrestricted.

The eu sets new safe intake

      For more than 30 years, MSG has been questioned but its safety has never been challenged, until recently, the European Union has come up with a new idea. In a study of neurodevelopmental toxicity, the critical dose of sodium glutamate in rats was 3.2 grams per kilogram (in glutamic acid). According to the results of the study, the panel to take 100 times the safe coefficient of the European food safety authority, set new safe intake for glutamic acid and its salts, 30 mg per kilogram of body weight, the equivalent of 60 kilograms of adults limit is 1.8 grams per day. The European Union believes that some consumers are clearly on the high side, especially among children and adolescents.

      Whether the eu will change the management of MSG is unclear, but it will undoubtedly trigger a new round of discussions in the food industry. In particular, the consumption of MSG, such as luncheon meat, ham sausage and steaks, etc. Thick soup, soy sauce, convenient fabric bag and other condiments; Spicy dry tofu and other heavy snacks.

      The evidence of exquisite asthma is inadequate

      The term "MSG causes asthma" was first reported in the 1980s, but so far there has been no reliable scientific evidence. Some people think they are sensitive to MSG, but scientists have not been able to get definitive results from the placebo experiment. In contrast, more scientists believe that MSG does not cause asthma.

      The biggest problem with the research evidence that MSG causes asthma is that experimental design is flawed. For example, the study subjects themselves were in an unstable condition of asthma, and during the study period, they were not allowed to continue taking drugs, leading to asthma attacks. In one of the latest "blind" studies, one patient developed an asthma response, but when the study was changed to double blind, the asthma response disappeared. Let the patient eat capsule, some capsule inside is monosodium glutamate, some capsule inside is a placebo. Single-blind refers to patients who don't know whether they're eating monosodium glutamate or a placebo, but doctors know that double blindness means doctors don't know either.

      In addition, the high temperature of MSG heats up chemical changes, producing a substance called pyroglutamate. The higher the heating temperature, the longer the time, the greater the ratio of glutamate to pyroglutamic acid, and the process of producing monosodium glutamate. It says that pyroglutamic acid may be carcinogenic or neurotoxic, but interestingly, there is no evidence of this in the scientific literature, and there is evidence to improve brain memory and cognitive ability. In fact, pyroglutamic acid is a circular amino acid that does not produce umami, and is an intermediate product of many amino acids and protein synthesis processes. It is also widely found in plants and animals, such as the human brain and spinal fluid, which have the pyroglutamate.

      MSG eats too much blood pressure and increases

      There are a lot of questions about MSG, but they are basically individual happenstance. For example, MSG leads to hives, and the European Union's expert group says that even if MSG can actually trigger hives, it's extremely rare. In individual cases, MSG may be associated with rhinitis symptoms, but there is no conclusive evidence. It seems like a common sense to eat a lot of MSG, but how much is it? The study found that monosodium glutamate promotes insulin secretion, but only if you eat 10 grams on an empty stomach. Some studies have found that monosodium glutamate can poison your brain, but you need to eat half a kilo at a time. In addition, animal studies have found that MSG may increase the risk of obesity, but it has not been found in several long-term studies. Of course, eating a lot of MSG will definitely affect blood pressure, after all, it's sodium.