Glutamate is an amino acid that is produced in the body and also occurs naturally in many foods. Monosodium glutamate (MSG) is the sodium salt of glutamic acid and is a common food additive. MSG is made from fermented starch or sugar and is used to enhance the flavor of savory sauces, salad dressings, and soups.
Both natural glutamate and monosodium glutamate are metabolized in the body using the same processes. Even though glutamate exists naturally in the body and healthy foods, many people worry that excess glutamate consumption can lead to health problems.
Why You Should Avoid Glutamate
Dietary glutamate has been examined in numerous studies to determine if it is safe to consume regularly. The relatively high glutamate levels in some traditional diets suggest that it is a safe food additive. However, anecdotal and scientific evidence indicates that high levels of glutamate and MSG consumption cause adverse health effects.
Glutamate consumption has been linked to the following:
Countless anecdotal reports have claimed that eating Chinese food high in MSG causes headaches. This sudden onset of heart palpitations and headache has been called “Chinese Restaurant Syndrome,” and the validity of these claims have been examined in several studies. One study concluded that MSG injures brain cells, and the resulting cellular inflammation leads to a headache.
Another group of researchers looked at how the body responds to one 150mg dose of MSG, observing pain sensitivity and blood pressure. Not only did the test subjects experience headaches and increased pain sensitivity, but also a short-term spike in blood pressure levels.
These observed effects of MSG consumption suggest that people with high blood pressure should avoid excessive MSG dietary intake.
Ingestion of MSG has been associated with increased insulin resistance and reduced glucose tolerance in animal studies. These effects can lead to obesity, although researchers have not yet determined if humans experience the same results. The same studies demonstrated that the ingestion of MSG also disrupts energy metabolism and causes inflammation and liver damage.
MSG consumption has been linked to increased pain sensitivity and pain intolerance, which has prompted investigations into MSG’s role in psychiatric disorders. There is strong evidence that MSG is a factor in schizophrenia, and it has been associated with anxiety, stress, and depression.
Foods With Glutamate
Most foods contain glutamate, so it’s challenging to eliminate it from the diet completely. The easiest way to reduce MSG consumption is to read nutrition labels. Many processed foods contain MSG, but may be listed under a different name in the ingredients list.
In addition to “monosodium glutamate,” look for:
- Hydrolyzed vegetable protein
- Autolyzed yeast
- Hydrolyzed yeast
- Yeast extract
- Soy extracts
- Protein isolate
You will find these flavor enhancers most often in sauces, soups, gravies, salad dressings, snack foods, and ready-meals.
Some foods have naturally occurring glutamates. Be aware of relying too much on these foods if you are concerned about glutamate consumption:
You will find the highest levels of glutamate in parmesan and Roquefort cheeses. Parmesan contains 1,680 milligrams of glutamate per 100 grams and Roquefort contains 1,280 milligrams per 100 gram.
2. Asian Sauces
Soy sauce, fish sauce, and oyster sauce all have very high levels of glutamate. Soy is naturally high in glutamate, and soy-based sauces will have concentrated levels of the compound. Soy sauce can have up to 1,700 milligrams of glutamate per 100 grams. Oyster sauce has 900 milligrams per 100 grams and should also be avoided.
Walnuts contain high amounts of glutamate. A 100 gram serving of walnuts contains 658 milligrams of glutamate. Also be aware of walnut butters and walnut oil which will also have concentrated levels of the amino acid and can cause reactions.
4. Processed Meats
Cured ham, either canned, frozen, or at the deli counter, should be avoided if you are worried about glutamate. Ham contains 340 milligrams of glutamate per 100 grams. This may seem like a moderate amount, but if you go for a second serving, you would consume nearly 700 milligrams of glutamate.
Fresh tomatoes are a glutamate source, and have up to 250 milligrams of glutamate per 100 grams. Be sure to avoid tomato sauce, tomato soup, and tomato-based dishes as well. A medium tomato weighs about 150 grams, and one ½ cup serving of tomato sauce could contain up to two tomatoes. That means your pasta could have up to 750 milligrams of glutamate. And that’s before you add the parmesan.
Grape juice contains moderate levels of glutamate. A 100 gram serving has 250 milligrams of glutamate, which is about ⅔ of a cup. A 12-ounce glass of grape juice will contain over 500 milligrams of glutamate, so it’s best to avoid it if you are keeping your glutamate consumption to a minimum. Also, keep in mind that tomato juice will have high levels of glutamate and should also be avoided.
Some fish, like anchovies, have moderate amounts of glutamate. A100 gram serving of anchovies contains 630 milligrams of glutamate. Scallops and oysters also contain glutamate, 160 milligrams and 150 milligrams per 100 grams respectively.
Dried shiitake mushrooms contain a whopping 1,060 milligrams of glutamate per 100 grams. White button mushrooms contain much less, only 180 milligrams per 100 grams, but those trying to eliminate glutamate from their diets should skip the mushrooms altogether.
A 100 gram serving of peas has 200 milligrams of glutamate. Compared to most other vegetables, peas contain more glutamate. If you must indulge, keep your portion size small to avoid overconsumption of glutamate.
10. Starchy Vegetables
Corn and potatoes contain relatively low amounts of glutamate, but may be problematic for some people. A 100 gram serving of corn or potato has around 100 milligrams of glutamate. A 100 gram serving of mashed potato is less than ½ cup, so portion size is key to minimizing glutamate consumption.
1. Cheddar Cheese
Cheddar cheese contains much less glutamate than parmesan or Roquefort. Per 100 grams cheddar contains 180 milligrams of glutamate.
2. Cod, Mackerel, Salmon
If you want to indulge in seafood, you are better off sticking to fish like cod, mackerel, or salmon. Mackerel contains 36 milligrams, salmon has 20 milligrams, and cod is the lowest with only 9mg of glutamate per 100 grams.
Relaxing herbs such as lemon balm, chamomile, and passion can offset the negative effects of glutamate by restoring its balance with gamma-aminobutyric acid (GABA).
Blueberries have been found to protect against glutamatergic excitotoxicity (nerve cell damage or death).