Eat a packet of chips, slurp down a bowl of noodles or enjoy a salami sandwich, and chances are you're also eating monosodium glutamate.
In recent decades, monosodium glutamate - better known as MSG - has found its way into many foods as a flavor enhancer.
But even today, the ubiquitous seasoning has had a less tasty history.
The alleged side effects of MSG were traditionally associated with eating Chinese cuisine and were called the "Chinese Restaurant Syndrome".
The term was first used by an American doctor in 1968, who wrote a letter to the highly respected New England Journal of Medicine questioning some of the symptoms he experienced after eating at several Chinese restaurants.
This led to a wave of similar articles in many medical journals and subsequent media coverage, leading to negative public perceptions about MSG and food in Chinese and Asian restaurants, in addition to harmful race-based stereotypes about the cuisine.
But in recent years, studies have failed to show a link between such widespread reactions and MSG consumption, and calls to drop the term are growing.
In 2020, the Merriam-Webster Dictionary updated the definition of Chinese Restaurant Syndrome with the label "dated, sometimes offensive" when it was declared by the Ajinomoto company, a long-time Japanese producer of MSG seasoning.
In late August, a group of American chefs, food writers, dietitians and public health scientists, backed by the Ajinomoto Group, wrote an open letter to the New England Journal of Medicine to scrap the "racist phrase once and for all."
Yet MSG remains shrouded in controversy when it comes to health.
We asked experts to answer five frequently asked questions about its science and safety.
What is MSG and how is it made?
We perceive five basic tastes: sweet, sour, bitter, salty and umami (also called savory).
Umami was first described by Japanese scientist Kikunae Ikeda in 1908. He attributed the meaty, savory taste of kombu dashi - a traditional Japanese broth made from dried fish known as bonito and dried seaweed - to a chemical called glutamate .
Shortly afterwards, Dr. Ikeda created a seasoning by binding glutamate with sodium, creating the water-soluble crystalline salt we know as MSG. He then teamed up with a company to bring the seasoning to market.
Today, MSG is made by fermenting starch, corn sugar or molasses from sugar cane or sugar beets.
Where is MSG found?
Because it enhances the meat flavor, MSG is widely used as a flavor enhancer.
It is added to foods such as meats, spices, spice mixes and snacks such as flavored chips and instant noodles. MSG is also found in manufactured ingredients such as yeast extract and hydrolyzed vegetable protein.
Aside from its full name, added MSG may be identified in the ingredients list on a food label as "flavor enhancer (MSG)" or by the food additive code number 621 or E621.
Our bodies also naturally produce small amounts of glutamate, and it is found in a variety of whole foods such as tomatoes and mushrooms.
If it is naturally present in food or ingredients, it does not need to be declared on food labels.
How does MSG work with our body?
When we take a mouthful of MSG-laden food, the glutamate portion of the MSG molecule binds to the umami taste receptors on our tongue and around our mouth, giving us the meaty kick that MSG is known for.
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It also stimulates saliva production, which helps other flavor molecules in food reach their receptors, making everything tastier, explains Emma Beckett, a food and nutrition scientist at the University of Newcastle.
Immediately after eating MSG, a small number of people may experience headaches, sweating, difficulty breathing and a tight face.
While a small portion of people may have a true MSG sensitivity, numerous studies have in most cases left out the seasoning as the cause of these effects, says Dr. Beckett.
"With the amounts in food, it's much more likely that if people are reacting, it's something else in the food or other food or drink consumed at the same time, or in the environment."
Is it safe to eat MSG?
Yes. According to Food Standards Australia New Zealand, MSG is considered safe to consume and does not pose a health risk to the general population.
"Too much of anything is a bad thing, but there are no studies showing long-term negative effects of regular MSG consumption," says Dr. Beckett.
Studies show harm from super high doses of MSG that exceed what people actually consume, she says.
When it comes to making delicious food, it's common for chefs and food content creators on social media to encourage a dash of MSG to enhance home cooking, such as the recent viral cucumber salad.
And that little bit of MSG could even be beneficial to someone's health.
"Adding MSG or MSG-containing spices to healthy foods like vegetables and grains can be a great way to make them tasty so you eat more," says Dr. Beckett.
"If it's a food that's high in sugar, high in calories, or high in fat, but also contains MSG, then it's probably not the MSG we should be focusing on."
Does MSG contribute to sodium intake?
It's possible. And eating too much sodium, in the form of common table salt (sodium chloride) or MSG, can cause high blood pressure and an increased risk of cardiovascular disease, stroke and kidney disease, explains nutritionist Kathy Trieu.
As co-director of the World Health Organization (WHO) Collaborating Center on Population Salt Reduction, and based at the George Institute for Global Health, Dr. Trieu is working toward the WHO's global goal of reducing sodium intake by 30 percent by 2025.
Last year, a WHO report found that the world was not on track to achieve this goal.
The global average sodium intake for adults is estimated at 4,310 milligrams per day (equivalent to 10.8 grams of table salt per day), which is more than double the WHO recommendation of less than 2,000 mg sodium per day (or less than 5 g sodium). per day of salt).
Dr. However, Trieu points out that MSG contains one-third less sodium than regular table salt.
"Plain salt contains more sodium and is therefore worse for your health," she says.
High blood pressure is a common health problem in Australia and reducing salt intake can reduce the risk. But most people find it difficult to change the way they cook and eat.
While it's fine to use a small amount of MSG in place of table salt when cooking at home, Dr. Trieu says there's an even better option: potassium-enriched salt.
"Like MSG, potassium-enriched salt contains less sodium, but also more potassium.
"Potassium is a mineral usually found in fruits and vegetables and actually lowers blood pressure and cardiovascular risk.
"There is compelling research showing that switching to potassium-fortified salt is beneficial to health."