What Is Miso Soup?
Miso soup is a traditional Japanese soup made from miso paste, a fermented soybean paste. The soup is often served with sushi and rice dishes, and it's usually the first course at a Japanese restaurant.
Is miso soup healthy?
Potential health benefits of miso soup include:
- Improved digestive health
- Reduced risk of cancer
- Reduced risk of heart disease
- Less severe symptoms of menopause
Scientific research supports many of these health benefits, but additional research is required.
What Is Miso?
Miso is a fermented paste made from:
- Steamed soybeans
In the two-stage fermentation required to create miso, koji is created first. Koji is made by combining a mold spore of the Aspergillus oryzae fungus with steamed rice or other grains like barley or soybeans. Koji also can be made using Saccharomyces cerevisiae and lactic acid bacteria.
For the second stage, koji is mixed with mashed soybeans, salt, and water to ferment into miso, a process that can take weeks or months, depending on the type of miso.
Koji mold contains enzymes, such as amylase and glutaminase, that turn proteins and starches into peptides, amino acids, and sugars. The glutamic acid is what gives miso paste an umami flavor.
Types of miso
There are more than 1,000 types of miso produced worldwide by many different cultures. How long the miso is left to age, or ferment, and the ingredients used to make it determine the color and flavor intensity of the miso paste. Some miso pastes you may see at your grocery include:
- White miso. Also called shiro miso, it's aged for the shortest amount of time. Of all the varieties, it is the mildest, sweetest, and least salty.
- Yellow miso. Also called shinshu miso, it's aged a bit longer. It produces a mild, earthier, but more acidic flavor.
- Red miso. Also called aka miso, it's typically aged the longest with the highest percentage of soybeans. The deep pungent flavor is salty and slightly bitter, so a little goes a long way.
- Kome miso. It's made from rice and soybeans and is the most commonly found type of miso in U.S. grocery stores. It can be white, yellow, or red.
- Genmai miso. It's made with brown rice instead of white. It produces a sweet, mild, earthy flavor that's great in stews.
- Mugi miso. It's made from barley and soybeans and isn't gluten free. It gives a mild and earthy taste.
Some new varieties of miso include farro miso and soy-free chickpea miso.
Beyond soup, you can use miso paste in stews, dips, casseroles, salad dressings, and marinades for fish, chicken, and meat.
What Does Miso Soup Taste Like?
Miso paste is the main ingredient in miso soup. Other additions that help make miso soup more flavorful include tofu, salt, green onions (also called scallions), mushrooms, and dried kelp or seaweed. Some Japanese miso soup recipes call for dashi stock, which is made from dried bonito, or salted fish flakes.
Our tongues can detect five main flavors in food: sweet, salty, bitter, sour, and umami. Miso soup has an umami flavor, thanks to the glutamic acid from the koji used to make miso paste. Umami, which roughly translates from Japanese to mean "good flavor" or "savoriness"—creates pleasing meaty, earthy, and savory notes. Depending on the type of miso paste used in the soup, the umami flavor may be delicate or more pungent.
Miso Soup Nutrition Information
Miso soup nutrition varies by what's included in the soup. A 1-cup (240-gram) serving using miso, tofu, chicken broth, seaweed or kelp, mushrooms, salted cod, and vegetable oil contains the following:
- Calories: 76.8
- Total fat: 3.74 grams
- Cholesterol: 9.6 milligrams
- Sodium: 1,470 milligrams
- Total carbohydrates: 5.45 grams
- Dietary fiber: 0.96 grams
- Sugars: 1.99 grams
- Protein: 6 grams
Miso nutrition information
One tablespoon, or 17 grams, of miso contains the following:
- Calories: 33.7
- Total fat: 1.02 grams
- Cholesterol: 0 milligrams
- Sodium: 634 milligrams
- Total carbohydrates: 4.32 grams
- Dietary fiber: 0.918 grams
- Sugars: 1.05 grams
- Protein: 2.18 grams
Miso and miso soup are also excellent sources of:
Sodium levels can vary for miso paste and packaged miso soups. Read the label before buying and choose one that's lowest in sodium if you're on a low-salt diet.
Miso Soup Benefits
Miso is a rich source of vitamins and minerals, as well as probiotics, known as the gut's "good bacteria." Much of the potential health benefits of miso paste are because of the fermentation process used to make it.
Soybeans, used to make miso paste, are also rich in protein and other important nutrients that contribute to a healthy diet.
Research has found a number of potential health benefits to consuming miso, including:
Healthier digestive system
Miso soup contains prebiotics and probiotics, which may contribute to improved gut health. Miso soup contains the prebiotic A. oryzae. In mouse studies, A. oryzae has been shown to reduce the risk of colitis.
The effect of miso consumption on gastrointestinal disorders in humans is less clear. One study of self-reported dietary habits of people in Japan found those who consume miso soup more often had lower levels of gastrointestinal problems, including dyspepsia, or indigestion, and gastroesophageal reflux disease.
Another study found people in their 60s and older who ate miso soup every day reported fewer stomach problems.
Reduced risk of heart disease
There may be a link between isoflavones, a type of chemical found in the soybeans used to make miso, and lowered risk of heart problems, though the research is still preliminary. One study showed that higher levels of these isoflavones correlated with lower risk of strokes and heart attacks in some Japanese women.
A meta-analysis and systematic review of studies found that consuming soy products, especially tofu and natto (a salt-free fermented bean product) was associated with a lower risk of type 2 diabetes and cardiovascular events, including a stroke. However, this risk reduction did not apply to consuming miso. That's because miso paste can often contain higher levels of sodium than tofu and natto.
Soy contains beneficial plant components including lecithin, isoflavones, stigmasterol, and soy protein peptides. These may help improve lipid profiles, reducing blood cholesterol and triglycerides, which in turn lowers the risk of heart disease.
Reduced risk of cancer
Consuming more soy and soy isoflavones is associated with a lower risk of overall cancer. That's according to a meta-analysis of cohort studies on soy consumption but not specific to miso intake.
One study showed that regular consumption of soybeans was linked with a lower risk of stomach cancer, particularly among women. But these findings may not translate to miso and miso soup. One study shows no link between miso soup intake and the risk of various types of cancer. And another study shows frequent miso consumption is linked to a raised risk of stomach cancer in Japanese men.
Two separate studies found consuming miso may reduce the risk of hepatocellular carcinoma in men, a primary type of liver cancer.
Eased or less severe menopause symptoms
Isoflavones also provide a range of health benefits, including the alleviation of hot flashes in women going through menopause. In addition, isoflavones can improve arterial health in these women.
Potential Risks of Miso Soup
Although miso soup has many health benefits and is a low-calorie, low-fat dish, there are a few potential risks:
Excess sodium intake
Some miso soup may contain too much sodium. It depends on how much and which kind of miso paste is used to make the soup. If you buy packaged miso soup, compare and read labels to see how much sodium is in a single serving.
Eating too much sodium can raise your risk of health problems, including high blood pressure, heart disease, and stroke. For overall health, adults should consume no more than 2,300 milligrams of sodium daily. If you have underlying medical conditions, such as hypertension and heart disease, you may need to consume even less sodium daily.
If you make miso soup from scratch, be careful how much and which kind of miso paste you use. Boost the flavor of your miso soup with healthier additives like scallions, mushrooms, cilantro, or even some grated ginger.
Thyroid medication interference
Soy products, like miso soup, are goitrogens, meaning they can affect how your thyroid functions. When consumed in moderation, goitrogens are generally safe, even for people with hypothyroidism.
However, if you are taking medication for hypothyroidism, avoid eating any soy products, including miso soup, close to when you take your medication. Soy can make it harder for your body to absorb your thyroid medicine. Follow your doctor's advice on when to take your thyroid medication—usually on an empty stomach. Wait at least an hour after taking your thyroid medication before eating or drinking anything, including soy products.
Food allergies from miso soup
Miso soup may trigger food allergies in some people. Symptoms of an allergic reaction can range from mild, such as tingling lips and tongue and a rash or hives, to severe symptoms, including difficulty breathing and anaphylaxis.
Miso paste is made using soybeans. Some people are allergic to soy protein. You should avoid miso soup if you have a soy allergy.
Most miso paste—the main ingredient in miso soup—is gluten free because the koji used is made with rice. But some miso paste, such as mugi miso, uses koji made with barley. And some packaged miso soup may also contain wheat gluten to give it body.
If you have Celiac disease, an autoimmune disease triggered by eating gluten, or have gluten sensitivity, ask if your miso soup is gluten free. And read labels on miso paste or packaged soups before buying.
Some traditional Japanese miso soups are made using dashi or fish stock or bonito or other dried fish flakes. If you have a seafood allergy, ask your server what type of stock is used to make the miso soup. And read labels on miso paste or packaged miso soups before buying. Not everyone with a seafood allergy will also have an allergy to fish. The only way to know for sure is to get allergy tested.
Miso Soup Recipe
It's easy to make your own miso soup at home.
Miso soup ingredients
Common miso soup ingredients include:
- Miso paste
- Dried and reconstituted seaweed
- Sliced green onions or scallions
- Fresh or dried (and reconstituted) shiitake mushrooms
- Dashi broth, which is traditionally made from kombu (dried kelp) and bonito or other salted fish flakes. You can find these ingredients in specialty aisle at your grocery or in specialty Asian food markets. If you are a vegetarian or vegan, you can use kombu-only broth or also use dehydrated mushrooms in place of bonito flakes.
To make a simple miso soup, use:
- White or shiro miso paste, 1/4 cup. You can try other mild miso pastes for miso soup.
- Soft tofu, 1/2 pound, cut into 1/2-inch cubes.
- 6 cups of dashi broth or kombu-only broth.
- Green onions or scallions, 1/2 cup thinly sliced.
Then follow these steps:
- First make the dashi broth: Add 1 ounce of kombu/dried kelp to 6 cups of water, bringing the mixture to a boil over high heat.
- Then remove the pan from heat, and add 1 cup of bonito flakes. If you have a fish allergy, you can skip the bonito flakes. Let the mixture stand for 4 minutes, then using a fine strainer, strain the soup.
- In a small bowl, add 1/4 cup of miso paste with 1/2 cup of dashi or kombu-only broth stirring until smooth.
- Add the rest of the dashi or kombu broth back into the saucepan over medium heat until hot.
- Add the tofu, simmering for 1 minute.
- Remove from heat and stir in the miso mixture.
- Top with scallions.
Is miso soup vegan?
Miso soup is vegan as long as it does not include dashi broth, which contains bonito or fish flakes. Some packaged miso soup may also contain ingredients like chicken or beef stock.
Miso soup is often served before or as a companion to Japanese meals such as sushi. The flavorful broth made from fermented soybean paste contains several beneficial vitamins and minerals. When buying packaged miso soup at the grocery, read the label to choose one that's low in sodium. If making miso soup at home, watch how much miso paste you use to avoid getting too much sodium in your diet.
Miso Soup FAQs
Is miso soup actually good for you?
Miso soup contains several beneficial vitamins, minerals, and components that may improve your gut and heart health and may lower your risk of cancer. If you are on a low-salt diet, read the label on packaged miso soup to choose one that's low in sodium.
What the heck is miso?
Miso is a fermented soybean paste.
Is miso soup just miso paste and hot water?
Miso soup can be as simple as miso paste and hot water topped with scallions or chopped up tofu. Some traditional Japanese miso soup recipes call for dashi stock, which is usually made from bonito or other salted fish. You also can add other ingredients to the miso soup base, including vegetables and ramen noodles.
Is instant miso soup healthy?
It depends on how much sodium is in the instant miso soup. Read the package label to see how much sodium is in a single serving. Instant miso soup may also contain other ingredients and preservatives, including wheat gluten, added salt, and monosodium glutamate or MSG.