MSG makes food so tasty, so why shouldn't we eat it?
Dietitian warns monosodium glutamate can trigger headaches, flushing, sweating, numbness, palpitations, chest pain, nausea, even mood changes
Can eating food with MSG cause headaches?
The straight answer: Yes
The facts: Many people avoid the flavour enhancer MSG, or monosodium glutamate, because they react negatively to it, citing headaches and other physical discomforts after eating any food containing it. As it turns out, there is a good reason behind these complaints.
According to Charmain Tan, registered dietitian at Seventeen Nutrition Consultants, MSG does indeed have the potential to cause headaches.
MSG is a kind of salt, a salt of the amino acid called glutamic acid. Glutamate imparts a unique taste to foods. Japanese professor Kikunae Ikeda, who discovered MSG, described it as umami, or the fifth taste after sweet, salty, sour and bitter. This taste is also often described as savoury, or xian wei in Chinese.
Glutamate is naturally abundant in almost all foods, such as tomatoes, potatoes, mushrooms, Parmesan cheese, and even breast milk.
Tan says that there are two forms for glutamate – “free” glutamate that is not bound to proteins, and “bound” glutamate. The former is the one that plays a role in the flavour-enhancing effects of food, the one that tastes umami. Foods with high levels of free glutamate include Parmesan cheese, ripe tomatoes and mushrooms. Protein-rich foods such as meat, poultry, fish and dairy products contain bound glutamate.
When stabilised with ordinary salt, glutamate is called monosodium glutamate. This can be purchased in packets or tins in stores. MSG is commonly used in the food industry as a flavour enhancer with an umami taste, and to intensify the savour of food.
The glutamate in MSG is an excitatory neurotransmitter, which causes increased activity in certain areas of the brain, Tan explains. MSG launches its “attack” by dilating blood vessels and exciting certain nerves in the brain.
“MSG does cause something that’s known as ‘Chinese restaurant syndrome’,” Tan points out. “Most complaints include headaches, flushing, sweating, numbness in the face and neck which can radiate down the arms and back, palpitations, chest pain, nausea and weakness, and even mood changes. Luckily, these symptoms are only temporary and often subtle.”
This does not mean that consuming MSG is harmful. The United States Food and Drug Administration has classified MSG as a food ingredient that is “generally recognised as safe”. Researchers have not found consistent evidence to support the link between MSG and “Chinese Restaurant Syndrome” and migraine headaches, despite complaints about these symptoms.
How much MSG is too much?
Tan says that no safe range has been established, as this varies from person to person. However, she says that if you are sensitive to it, then you should reduce the intake of this additive or avoid it completely.
Do also note that MSG may be contained in a number of other ingredients such as “Accent”, autolysed yeast extract, hydrolysed vegetable protein, potassium glutamate, sodium caseinate, broth, textured protein, and natural flavourings.
Ingredients that are protein-fortified, fermented, ultra-pasteurised or enzyme-modified also contain MSG.
“If you have high blood pressure and need to watch your sodium intake, you should limit your intake of MSG as well,” Tan adds. “When eating out, ask for your meal to be prepared without MSG, or order a bowl of rice to accompany your favourite Chinese dish to minimise the headache-causing effect.”