by Rachael Link, MS, RD
MSG is one of the most controversial ingredients on the planet. While some claim that it’s a totally safe and healthy food additive that can help ramp up flavor and minimize sodium intake, others have dubbed it a cancer-causing food and have tied it to side effects like headaches and high blood pressure.
Despite being found in abundance throughout much of the modern food supply, MSG should by no means by a staple ingredient in a healthy diet. Not only can it cause negative symptoms in certain people who are sensitive to its effects, but it’s also primarily found in unhealthy, heavily processed foods that are lacking in the essential nutrients that your body needs.
So why is MSG bad, and how can you be sure to keep your intake in check to reduce the risk of adverse side effects? Here’s what you need to know.
What Is MSG?
MSG, also known as monosodium glutamate, is a common ingredient and food additive used to boost the flavor of processed, canned and frozen foods. MSG seasoning is derived from glutamic acid, a type of protein that is abundant in many types of food, including fruits and vegetables. It’s produced through a fermentation process and brings a savory taste to dishes.
So why is MSG controversial? Because it contains an isolated and highly concentrated form of glutamic acid, it’s processed very differently in the body and can increase levels of glutamate in the blood very rapidly. It’s believed that this can cause a long list of potential side effects, with studies linking excess MSG consumption to everything from asthma attacks to metabolic syndrome and beyond.
MSG Side Effects and Dangers
- Causes Reactions in Some People
- Can Cause Free Radical Formation
- May Contribute to Weight Gain
- Could Increase Blood Pressure
- Has Been Linked to Asthma Attacks
- Could Be Linked to Metabolic Syndrome
- Found Mostly in Unhealthy Foods
1. Causes Reactions in Some People
Research shows that certain people may be especially sensitive to the effects of MSG and may experience a slew of negative MSG side effects after consuming it. Nicknamed the “Chinese restaurant syndrome,” one study actually showed that MSG triggered side effects in many people with a reported sensitivity to MSG, causing symptoms like muscle tightness, numbness/tingling, weakness, flushing and the well-known MSG headache. (1)
Although researchers are not entirely certain what causes MSG sensitivity, they have theorized that eating large amounts can cause small amounts of glutamate to cross the blood-brain barrier, interacting with the neurons to cause swelling and cell death. (2)
2. Can Cause Free Radical Formation
Some animal models and in vitro studies have shown that consuming large amounts of monosodium glutamate could cause oxidative damage to the cells and contribute to free radical formation. For example, one animal model published in the Journal of Cardiovascular Disease Research showed that feeding rats very high doses of MSG increased the levels of several markers of oxidative stress in the heart tissue. (3) Free radical formation has been tied to the development of chronic conditions, such as heart disease, cancer and diabetes. (4) However, keep in mind that most research shows that it would take a very high dose of MSG significantly greater than the average intake to cause damage.
3. May Contribute to Weight Gain
Studies are still inconclusive when it comes to the effects of MSG on weight control. Although some research shows that it can enhance satiety to keep you feeling full and decrease intake, still other studies have found that it may actually be associated with weight gain and increased intake.
One study published in the British Journal of Nutrition, for instance, showed that adding MSG to a high-protein meal had no effect on satiety and actually increased caloric intake later on during the day. (5) Meanwhile, other studies have found that regular consumption of MSG could be associated with weight gain and a higher risk of being overweight in certain populations. (6, 7)
4. Could Increase Blood Pressure
High blood pressure is a serious condition that can place excess strain on the heart and cause the heart muscle to slowly weaken over time. Along with high cholesterol and triglyceride levels, having high levels of blood pressure is one of the major risk factors for developing heart disease. (8)
In a 2015 study published in the journal Nutrition, researchers found that consuming high amounts of monosodium glutamate resulted in significant increases in both systolic and diastolic blood pressure. (9) Similarly, another study conducted by the Jiangsu Provincial Centre for Disease Control and Prevention showed that MSG intake was associated with higher levels of blood pressure over a five-year period in Chinese adults. (10)
5. Has Been Linked to Asthma Attacks
Some studies have found that MSG intake could be linked to a higher risk of asthma attacks in those who are at risk. A study published in the Journal of Allergy and Clinical Immunology tested the effects of 500 milligrams of MSG in 32 people with asthma and found that a shocking 40 percent of participants experienced a worsening of asthma symptoms within 12 hours of ingesting MSG. Not only that, but nearly half of those who experienced a reaction also reported side effects associated with Chinese restaurant syndrome, such as headaches, numbness and flushing. (11)
6. Could Be Linked to Metabolic Syndrome
Metabolic syndrome is a group of conditions that can significantly increase your risk of developing problems like heart disease, diabetes and stroke. Some of the risk factors for metabolic syndrome include having high blood sugar, increased blood pressure, excess amounts of belly fat or abnormal cholesterol levels. (12)
Multiple studies have linked MSG to several of these conditions, including high blood pressure and obesity. Another study out of Thailand also showed a direct association between the consumption of monosodium glutamate and a higher risk of metabolic syndrome among 349 adults. (13)
7. Found Mostly in Unhealthy Foods
Regardless of whether or not you have a sensitivity to monosodium glutamate, it shouldn’t be a regular part of your diet. This is because it’s found primarily in ultra-processed foods that offer little in terms of nutrition apart from extra calories, refined carbs, fat and sodium. Filling your diet with unprocessed, whole foods, on the other hand, is the easiest way to minimize your dietary intake of MSG and supply your diet with the vitamins and minerals that you need.
Any Potential Benefits?
While the majority of research shows that overdoing it on the monosodium glutamate can have negative effects on your health, there may be some potential benefits that should be considered as well.
Monosodium glutamate is often used to bring out and enhance the flavor of savory dishes and can often lessen the need to pile up on the salt in your favorite foods. Going overboard on the foods high in sodium can have detrimental effects on health, with some research linking excess sodium intake to high blood pressure, bone loss and kidney problems. (14, 15, 16) Pairing MSG with a small amount of salt is estimated to help cut down on sodium intake by 20 percent to 40 percent, which could be beneficial for some people. (17)
Additionally, although several studies have tied MSG intake to weight gain and obesity, other studies have turned up conflicting results, reporting that it could actually enhance satiety and reduce caloric intake at subsequent meals. (18, 19) Given these inconsistent findings, more research is needed to further understand the role that monosodium glutamate may play in weight management.
Top 15 Foods with MSG to Avoid
Unfortunately, there are many hidden sources of MSG in food, and it can be found in everything from fast food to meat products. The best way to find out if MSG is lurking in your favorite foods is to simply check the label and look for ingredients like “monosodium glutamate,” “glutamic acid,” “glutamate” or “yeast extract.”
Here are a few of the top foods with MSG to keep a look out for on your next trip to the grocery store:
- Potato chips
- Fast food
- Convenience meals
- Iced tea mixes
- Salty snacks
- Instant noodles
- Sports drinks
- Processed meats
- Canned soups
- Soy sauce
- Salad dressings
MSG vs. Salt/Sodium
Much like MSG, consuming high amounts of sodium can contribute to a long list of potential health problems. In fact, high sodium intake has been associated with issues like high blood pressure, bone loss and impaired kidney function, as noted above.
MSG contains sodium but has about one-third the amount of sodium as table salt, which is why it’s often used to reduce the sodium content of processed foods while still supplying the same level of flavor. In fact, according to the European Food Information Council, combining MSG with a small amount of table salt can reduce overall sodium intake by 20 percent to 40 percent.
It’s best to keep your intake of both in moderation on a healthy diet. Reducing your intake of processed foods and unhealthy snacks is the best way to cut down on both sodium and MSG consumption. Instead, fill your diet with plenty of nutrient-rich ingredients like fruits, vegetables, protein foods and whole grains, and try experimenting with other spices to add an extra dose of flavor without the negative side effects.
MSG vs. Glutamate
Glutamate, also known as glutamic acid, is an important amino acid found in many types of foods, including mushrooms, meat, fish, milk and tomatoes. It has natural flavor-enhancing properties that can help enhance the taste of many dishes naturally.
Monosodium glutamate, on the other hand, is defined as the sodium salt of glutamic acid. Initially discovered in 1908, MSG is a product often used in many foods today that is produced through a fermentation process.
The main difference between glutamate and monosodium glutamate, however, is in the way that they are each processed within the body. The glutamate found in foods is typically attached to a long chain of other amino acids. When you eat it, your body breaks it down slowly and is able to closely regulate the amount that you take in. Excess amounts can simply be excreted through the waste to prevent toxicity. (20)
Meanwhile, MSG is produced using a concentrated form of glutamate that is isolated, meaning that it’s not attached to other amino acids and can be broken down very quickly. This also means that it can raise levels of glutamate in the blood much more rapidly, contributing to symptoms in those with a sensitivity.
For this reason, the glutamate in foods is generally not a concern for most people and has not been linked to the same negative side effects. The monosodium glutamate found in processed foods, however, has been associated with a long list of symptoms, including headaches, high blood pressure, weight gain and asthma attacks.
How to Avoid MSG
MSG is a common ingredient in many types of processed foods, from salty snacks to frozen convenience items and beyond. The best way to completely cut out all MSG food sources from your diet is to simply minimize your intake of processed junk foods and incorporate more healthy, whole foods into your weekly rotation instead.
You can also start reading food labels to make sure your grocery list is completely MSG-free. Look out for some of the other names for MSG, including monosodium glutamate, glutamic acid, calcium glutamate and other similar variations. Other ingredients like yeast extract, sodium caseinate and hydrolyzed products can also indicate that there may be MSG present as well.
Healthier Alternatives and Recipes
MSG is a popular component in many Asian dishes and noodle-based recipes. However, there are plenty of ways to enjoy your favorite savory meals without adding monosodium glutamate.
Mushrooms, tomatoes and parmesan cheese are three natural, healthy sources of glutamic acid that can be added to dishes to punch up the flavor. Experimenting with some healing herbs and spices in your foods can help maximize taste while also delivering a host of health benefits.
Here are a few healthy and homemade MSG-free recipes that you can try to satisfy your tastebuds:
So how is MSG made? The history of MSG can be traced all the way back to 1866, which is the year that German biochemist Karl Heinrich Ritthausen first discovered glutamic acid after treating wheat gluten with sulfuric acid. A few years later in 1908, Japanese chemist Kikunae Ikeda isolated glutamic acid as a taste substance from a type of seaweed called kombu and realized that it was responsible for a new taste that had not yet been scientifically described called umami.
Ikeda began studying the taste of specific glutamate salts and soon discovered that sodium glutamate was the easiest to crystallize, the most palatable and most soluble among them. Just a year later, a Japanese food company began the commercial production of monosodium glutamate.
Today, MSG is a common component of many Asian dishes and is known for supplying its signature savory taste to broths, meats and noodle dishes. However, as more research continues to emerge on the potential side effects of this popular seasoning, many food manufacturers and restaurants have begun offering MSG-free items and ingredients on their menus.
Because MSG contains a concentrated amount of free glutamic acid, it can increase glutamate levels in the blood rapidly. While some people can tolerate moderate amounts without noticing any side effects, it can contribute to symptoms like headaches, flushing and muscle tightness in those with an MSG allergy or sensitivity.
However, MSG is primarily found in heavily processed, unhealthy foods, so it shouldn’t be a staple in your diet, regardless of whether or not you experience any of these side effects. If you do notice any adverse symptoms after consuming foods high in MSG, try reducing your intake by minimizing your intake of common monosodium glutamate food sources.
Keep in mind that it’s often lurking in many different types of food — even many masquerading as health foods — so be sure to pay close attention to the ingredients label of your foods and increase your intake of nutrient-dense foods like fruits, vegetables, unprocessed meats, nuts and seeds to ensure your diet is low in MSG.
- What is MSG? Also known as monosodium glutamate, it is a common food additive made from the sodium salt of glutamic acid, a common amino acid found throughout the food supply.
- So is MSG bad for you? Some studies have linked monosodium glutamate to weight gain, high blood pressure, asthma attacks, metabolic syndrome and short-term side effects in those who are sensitive.
- Additionally, it’s also found mostly in unhealthy processed foods that should be kept to a minimum on a healthy diet. Some of the most common sources of MSG include processed foods, salty snacks, seasonings and convenience items.
- To reduce your intake of MSG, fill your diet with nutrient-rich whole foods and practice label reading to ensure MSG isn’t found in your favorite ingredients.