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Is MSG really bad for you?

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The not-so-secret ingredient to many delicious Asian dishes could actually be a health hazard.

Monosodium Glutamate (also known as MSG) is a commonly used seasoning, especially in Chinese restaurants. Most people deem it unhealthy, causing thirst, hair loss and headaches. However, is it really bad for you? In this article, we will explore what MSG is and the health theories behind it.  

How Is MSG Formed?

Monosodium glutamate sounds scientific. However, it is not formed by chemicals in a lab. You might be surprised to find out that it is made by fermenting natural ingredients like tapioca, sugar beets or sugar cane. It originated in Japan in 1907 by a university professor called Kikunae Ikeda. After fermentation, the glutamic acid broth is heated and dried to form concentrated glutamate sprinkled on your food for the ‘umami’ taste. ‘Umami’, which translates to savoury, is associated with a meaty flavour and is a highly sought-after taste by many. Behind this taste is the magic ingredient glutamate. 

What Other Foods Contain Glutamate?

MSG is made up of 78% glutamate, 12% sodium and water. But it is not the only seasoning or food that contains glutamate. Oyster sauce, chilli sauce and processed meats (ham and sausages) also contain glutamate. If you read your food labels and notice the words “yeast extract” or “hydrolysed yeast”, this means that glutamate has been added. Glutamate, which is an amino acid, also occurs naturally in a wide range of food. These foods include tomatoes, parmesan cheese, dried mushrooms, soy sauce, fruits and vegetables. A shocking fact is that even breast milk contains glutamate. According to the FDA, the glutamate in MSG is chemically indistinguishable from glutamate present in food proteins. Our bodies ultimately metabolise both sources of glutamate in the same way. 

Why is it Bad for You?

It all started out with a letter written by Dr Robert Ho Man Kwok to the New England Journal of Medicine in 1968. In the letter, Dr Kwok talked about the possibility that MSG can cause general weakness, heart palpitations and a feeling of numbness in the back of the neck that spreads to the arms and back. It was termed the “Chinese Restaurant Syndrome”. This gave a very bad reputation, with restaurants going the extra mile to proclaim that their food contains zero MSG. The scientific community also started experimenting on animals and even conducted human studies to find out what large doses of MSG can cause.

What Experiments And Studies About MSG Revealed?

Initially, experiments seemed to prove Dr Kwok’s theory. Washington University researcher Dr John W. Olney injected enormous doses of MSG into the skin of newborn mice. These mice grew into adulthood being stunted and obese. The same results were noted in infant rhesus monkeys. However, these were isolated results. 19 studies by other researchers did not show similar trends. Human studies, where the participants were not told what they were given (MSG or placebo), also failed to confirm an involvement of MSG in “Chinese Restaurant Syndrome” or other idiosyncratic intolerance. MSG also has not been shown to provoke constriction of the airways in asthmatics. As for hair loss, there is no strong evidence of a causal link to MSG consumption. 

What Is The Expert and Scientific Committee Opinion About MSG?

  • The overall safety evaluation by JECFA (Joint FAO/WHO Expert Committee on Food Additives) concluded in 1988 that the total dietary intake of glutamates from foods that naturally contain glutamates and when used as a flavour enhancer, do not represent a hazard to health. Due to this conclusion, the JECFA did not set an acceptable dietary intake of MSG. 
  • The SCF (Scientific Committee for Food of the Commission of the European Communities) also took the same approach in 1991. 
  • In addition, FDA also considers the addition of MSG to foods as “Generally Recognised as Safe”. 
  • However, in 2017, when the European Food Safety Authority (EFSA) re-assessed the safety of glutamates used as food additives, it derived a group acceptable daily intake of 30 mg/kg body weight per day. If you are 70kg, that works out to be about 2.1g per day. According to the FDA, a typical serving of food with added MSG contains less than 0.5 grams.

Who Should Avoid or Limit Their MSG Intake?

The following groups of people should avoid or at least limit the intake of MSG.

  • MSG-Sensitive people: Scientists have not been able to consistently trigger reactions in studies with individuals that identify themselves as MSG-sensitive. However, if you identify yourself as being sensitive to MSG, you can choose to avoid it by reading your food labels and choosing options with “No MSG” or “No added MSG”. 
  • Certain asthmatic people: If you have asthma and suspect that MSG causes breathlessness or triggers your asthma attack, you should also avoid MSG. 
  • People with high blood pressure: If you have high blood pressure, you should limit your salt intake. This also includes MSG intake as one teaspoon of it still contains close to 700 mg of sodium. The recommended daily sodium limit is 2000 mg. 

Conclusion 

MSG has had many controversies ever since the 1960s. Ultimately, your food is your choice. It is important to understand what MSG is made of and the scientific evidence behind the theories behind it. These will help you evaluate and make an informed decision about what you eat.

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