Key Points:
- Miso is a fermented soybean paste that brings a savory, “umami” flavor to dishes like soups, dressings, and marinades.
- There are several types of miso, ranging from mild white and yellow varieties to stronger red, barley, and soybean miso.
- Miso provides probiotics, antioxidants, and soy isoflavones, which may support digestion, immunity, heart health, and relief from menopause symptoms.
- While miso’s antioxidants and soy compounds may be protective, studies also show that eating large amounts of salty foods, including miso soup, may increase stomach cancer risk.
- People with soy allergies, thyroid concerns with high soy intake, or those who need to avoid gluten should use caution and always check labels.
- To get the most benefit, enjoy miso in moderation and add it near the end of cooking to preserve its flavor and beneficial microbes.
If you’ve spotted miso on a menu — most often as miso soup — you may have wondered what exactly it is. Perhaps you’ve tried the soup before and are curious about how else this unique ingredient can be used, or even whether it’s a healthy choice.
Miso is far more versatile than many people realize, and it brings both distinctive flavor and potential health benefits to the table.
What is miso?
Miso is a savory paste made by fermenting cooked soybeans with a grain—most often rice or barley — and a special mold called Aspergillus oryzae. This mold, the same one used to make soy sauce and sake, is first added to the grain to create a starter called koji. The koji is then mixed with the soybeans and salt, and the blend is left to ferment. Depending on the style, the fermentation process can take anywhere from a few weeks to several years.
Types of Miso
Miso comes in several varieties, each with its own flavor and culinary uses:
- White miso (shiro): Mild, lightly fermented, and sometimes called “sweet” or “mellow” miso. Great for soups, sauces, and dressings.
- Yellow miso (shinshu): A bit more fermented than white miso, with a slightly stronger taste. Versatile and easy to use in many dishes.
- Red miso (aka): Aged the longest, with a robust, salty, and pungent flavor. Best for hearty soups, marinades, and glazes.
- Barley miso (mugi): Made with barley and soybeans, fermented longer than white miso, and known for its distinct barley aroma.
- Soybean miso (hatchō): Made only from soybeans and aged up to three years. Very dark in color and intensely flavored.
Miso’s origins
While miso is most closely tied to Japanese cuisine today, its roots go back much further. Historians trace its beginnings to ancient China, where a soybean paste called jiang was widely used. Buddhist monks later introduced jiang to Japan (and Korea), where it gradually evolved into what we now know as miso. The word “miso” itself translates to “fermented beans” in Japanese.
Over the centuries, different varieties of miso developed across Japan, each with its own regional character. By the 17th century, miso was being produced on a larger, more industrial scale, helping it spread even further. Today, miso remains a cornerstone of Japanese cooking and is also gaining popularity around the world for both its distinctive flavor and potential health benefits.
Health benefits of miso
Miso may offer a variety of health benefits, thanks to its fermentation process and soybean base:
Supports digestion
Like other fermented foods, miso contains probiotics — beneficial bacteria that help keep the digestive system balanced. Eating probiotic-rich foods may ease common issues such as gas, constipation, and diarrhea, and may also help manage conditions like irritable bowel syndrome and inflammatory bowel disease.
Strengthens the immune system
Because probiotics play a role in gut health, they may also support immune function. A healthy gut microbiome can help lower the risk of infections and improve overall resilience.
Provides antioxidants and may protect against some cancers
Animal studies suggest miso could reduce the risk of certain cancers, including stomach, colon, lung, and breast cancer. Some human studies also show potential benefits for liver and breast cancer risk. Miso is rich in antioxidants, which help fight damage from free radicals. However, it’s worth noting that high sodium intake from miso soup has also been linked to a higher risk of stomach cancer, underscoring the importance of moderation.
Eases menopause symptoms
Soybeans are a natural source of isoflavones, plant compounds that act somewhat like estrogen in the body. These compounds may help reduce hot flashes and other symptoms in menopausal women.
Potential downsides
While miso has plenty of benefits, there are a few things to keep in mind.
Sodium content
Miso is quite high in sodium — about 634 milligrams in a single tablespoon. The American Heart Association recommends keeping daily sodium intake under 2,300 milligrams, and people with high blood pressure, kidney disease, or heart failure may need even less. Eating miso in moderation or choosing lower-sodium varieties can help keep intake in check.
Soy considerations
Because miso is made from soybeans, it isn’t suitable for anyone with a soy allergy. Soy also contains naturally occurring compounds called goitrogens, which may interfere with thyroid function in some cases, particularly for those with iodine deficiency or high soy consumption.
Gluten concerns
Not all miso is gluten-free. Some varieties are made with barley or other gluten-containing grains, so it’s important to check the ingredient list if you need to avoid gluten.
Miso nutrition
Here’s a look at the nutrition you’ll get from miso:
One tablespoon of miso paste contains about:
- 34 calories
- 1 gram of fat (0.2 grams saturated)
- 4 grams of carbohydrate
- 1 gram of sugar
- 1 gram of fiber
- 2 grams of protein
- 634 milligrams of sodium
One cup of miso soup provides, on average:
- 60 calories
- 3 grams of fat (0.5 grams saturated)
- 3.5 grams of carbohydrate
- 1 gram of sugar
- 1 gram of fiber
- 6 grams of protein
- 1,071 milligrams of sodium
In addition, miso contains small amounts of several vitamins and minerals, including vitamin K, some B vitamins, copper, manganese, iron, and zinc, which can contribute to your overall nutrient intake.
Because miso is high in sodium, it’s best enjoyed in moderation. If you’re watching your salt intake, look for lower-sodium varieties or ask your dietitian how miso might fit into your eating plan.
Ways to use miso
Miso adds a salty, savory depth of flavor known as umami — often described as meaty or brothy. When cooking with miso, it’s best to stir it in toward the end of cooking to preserve its flavor (and beneficial microbes). And since a little goes a long way, you don’t need much to make an impact.
Here are a few simple ways to try miso at home:
- Stir it into soups for extra flavor.
- Use it as a marinade for meat or poultry.
- Brush it onto fish before broiling or grilling.
- Whisk it with oil and vinegar to make a tangy salad dressing.
- Add it to stir-fry dishes for a quick flavor boost.
Miso is widely available in most grocery stores and at Asian markets. Choose the type that fits your taste and recipe, and store it tightly sealed in the refrigerator to keep it fresh.
For inspiration, you can try this easy Ginger-Miso Grilled Asparagus recipe from Bon Appétit.
Whether stirred into a soup, whisked into a dressing, or brushed onto fish, miso can be a flavorful and nutritious addition to your meals — as long as it’s enjoyed in moderation.
Want to learn more about eating well? Read “Strategies for Healthy Eating,” “Improving Your Recipes: One Step at a Time,” and “Easy Ways to Eat Better.”
