Miso Paste Nutrition Facts and Health Benefits

Miso paste, or simply miso, is a paste made from fermented soybeans. There are many different types of miso paste, but all of them are made with soybeans and koji (Aspergillus oryzae), a Japanese fungus that is developed using soybeans.

Koji is the fermenting agent. In addition to those two ingredients, most types of miso paste are also made from some type of rice or grain.

Miso paste originated in China but was brought to Japan about 1,300 years ago by Buddhist priests who used it to preserve foods during summer months. Over the years, miso became a staple in the Japanese diet.

Today, miso paste is used for pickling vegetables, fish, and meats. It is also the key ingredient in miso soup. Miso paste imparts an "umami" or savory flavor to foods. It is relatively high in protein (compared to other condiments) but also high in sodium.

Miso Paste Nutrition Facts

The following nutrition information is provided by the USDA for one tablespoon (17g) of miso paste.

Carbs

A one-tablespoon serving of miso paste provides 33.7 calories and has 4.3 grams of carbohydrates. There is a small amount of sugar (1.1g) and fiber (0.9g) in miso paste. You're not likely to consume a great deal of miso paste so the carbs, fiber, or sugar are not likely to make a substantial difference in your diet. Most recipes call for one to two tablespoons of the paste, at most.

There is no recorded glycemic index or glycemic load for miso paste. But since the portion size is generally small and since the food contains few carbohydrates, it is likely that the impact on blood sugar is minimal. In general, soy foods like miso paste, are believed to have a low glycemic response.

Fats

Miso paste is low in fat, providing just one gram per serving. About 0.2 grams of the fat is saturated, while 0.2 grams is monounsaturated, and about 0.5 is polyunsaturated, according to USDA data.

Protein

Miso paste provides about 2.2 grams of protein in each one-tablespoon serving.

Vitamins and Minerals

Some sources promote the substantial vitamin and mineral content of miso paste, most notably B vitamins, manganese, copper, and vitamin K. But because it is consumed in such small amounts, you may get fewer micronutrients than you expect. A one-tablespoon serving is not a good source of any vitamins or minerals (except sodium) according to government guidelines.

For instance, it is widely reported that miso is a good source of copper. But a one-tablespoon serving provides 0.07mg or 7.8% of the daily value. Some sources also report that miso is high in B vitamins. But a tablespoon serving provides just 0.034mg of vitamin B6 (about 2% of the daily value) and 0.014 micrograms of vitamin B12 or about 0.05% of the daily value.

It is also commonly reported that miso is a good source of vitamin K. But again, a typical one-tablespoon serving only provides just under 5 micrograms or about 4% of the daily value. A serving of miso also provides 0.15 micrograms of manganese or 0.6% of the daily value.

The only significant micronutrient in miso paste is sodium. A one-tablespoon serving provides 643 milligrams of sodium, according to USDA data. Government guidelines suggest that we consume no more than 2,300 milligrams per day.

Health Benefits

Foods like miso paste that are consumed in very small quantities don't always provide substantial health benefits. But there are some ways that adding miso paste to your diet may provide certain advantages to some people.

Better Blood Glucose Control

There is some evidence that adding soybean foods like miso, natto, and ground soybean to other food may improve glycemic response in some people. In fact, in one study researchers found that adding miso to white rice lowered its glycemic index by 20% to 40%.

Study authors stated that that soy foods may be an appropriate part of diets intended to improve control of blood glucose and insulin levels. However, the study was small in scope, including only ten people (two women, eight men) who were relatively young (average age 23 years), and normal weight. So study authors also noted that further research is required before any conclusions can be drawn.

Lower Blood Pressure and Heart Rate

A 2020 research review published in the journal Environmental Health and Preventative Medicine explored the relationship between the health effects of salt consumed in miso soup to salt consumed from other foods. High salt intake is known to increase blood pressure and is associated with hypertension incidence.

In the report, the study authors found that based on current evidence, the intake of miso soup does not increase blood pressure and heart rate compared with the equivalent intake of salt. They suggested that the effect is in part due to the lowering of sympathetic nerve activity. Ingredients in miso reduce the effects of sympathetic nerve activity, resulting in lowered blood pressure and heart rate.

Lower Cholesterol

There is some evidence that fermented soy foods such as miso, natto, and douchi that are rich in protein can reduce the serum concentrations of total cholesterol, low-density lipoproteins (LDL cholesterol), and triglycerides if consumed instead of animal protein.

Interest in fermented foods (including fermented grain, dairy, and animal foods) has increased recently. Researchers don't fully understand the range of benefits, however, and studies are ongoing.

May Reduce Inflammation and Prevent Disease

Including soy foods in your diet may provide benefits because they contain isoflavones, a phytoestrogen similar to the hormone estrogen. Aglycone-type isoflavones are produced during the fermentation of miso.

Isoflavones have been shown to exhibit antioxidant, anticancer, antimicrobial, and anti-inflammatory properties. Evidence has suggested that they may have the potential to prevent chronic diseases in which inflammation plays a key role, though the underlying mechanisms remain unclear.

Some researchers have expressed concern, however, about long-term high-dose use of isoflavones. But the evidence is both incomplete and contradictory. According to one group of researchers who wrote a review of isoflavone studies, "the negative effects of isoflavones may rely on diverse factors such as age at the time of exposure and the hormonal environment."

May Help Protect Gut Health

Melanoidins are also produced during the fermentation of miso. Melanoidins were previously considered to be inert, however, recent research into their nutritional, physiological, and functional properties has suggested that they may have antioxidant properties. Antioxidants help protect cells against oxidation caused by free radicals.

Melanoidins may also protect against radical stress in the colon and behave as a dietary fiber by promoting the growth of gut bifidobacteria. However, studies investigating the benefits of melanoidins have been conducted using other foods such as coffee or beer, not miso paste.

There are other foods that are likely to provide more substantial antioxidant benefits, such as fruits and vegetables.

Allergies

Because miso is made with soy, those with a soy allergy should avoid it. Soy is a common allergy, especially in children. People allergic to wheat, beans (legumes), milk, or other food can also have an allergic reaction to soy.

Symptoms of soy allergy range from mild, including hives or itching in and around the mouth, to severe reactions including anaphylaxis, which can be life-threatening.

Adverse Effects

Certain people should be cautious when consuming miso paste. Those with Celiac disease or non-celiac gluten sensitivity should be careful when choosing the type that they consume, as many types are made with gluten-containing grains, such as barley.

Even brands that don't contain any gluten grains, might be subject to cross-contamination because they are manufactured in a processing facility that also makes gluten-containing miso. Be sure to read labels carefully and look for one that is specifically marked as safe for those on a gluten-free diet.

Also, those who are watching their sodium intake should be cautious about consuming miso paste. While there may be some variation between brands, the condiment is known to be salty.

Lastly, certain depression medications (MAOIs) may interact with fermented soy products, such as miso paste or soy sauce, due to their potentially high level of the amino acid tyramine.

In some cases, consuming tyramine can lead to the release of norepinephrine, which can cause a rapid increase in blood pressure. People taking MAOIs are advised to limit tyramine intake, by avoiding foods such as soybean condiments, tofu, and even tap beer.

Varieties

There may be as many as 1,000 different types of miso as the paste has been produced and used for thousands of years. But there are three traditional types that you're likely to find when shopping for it today. They are described by the Japan Miso Promotion Board.

• Mugi miso is made from soybeans, roasted barley, and salt. This is a sweeter, lighter miso.
• Kome miso is made from soybeans, malted rice, and salt. Also called "rice miso," this type is widely available in white, yellow, and red varieties.
• Mame miso is made from soybeans, malted soybeans, and salt. This dark reddish-brown miso is the only type made entirely from soybeans.

When It's Best

Miso paste is available all year long in almost any supermarket. You'll find it in the Asian food section of most major markets. You'll also find many different types of miso paste in Asian markets and online.

Storage and Food Safety

Miso paste should be stored in an airtight container and refrigerated after opening. when stored properly, it should remain fresh for about a year, according to the USDA. Miso paste should not be frozen.

How to Prepare

There are countless ways to use miso in your day-to-day cooking. The most common use is to make miso soup. This popular Asian staple is generally made from miso, water, tofu, dashi (fish-based stock seasoning), and green onions. Some people also add sesame seeds, carrots, or other ingredients.

When making miso soup, you'll want to warm the base first. Usually, this means heating water and adding dashi, or veggies (such as green onions or carrots) on the stove. Tofu and miso paste are usually added towards the end of the cooking process. Heat can break down miso and it changes the flavor, so you want to make sure that the soup isn't too hot when it is added.

But miso soup is just one way to use this versatile food. Miso can be added to other types of soups, can be used to coat vegetables, make salad dressing, added to sauces or gravy, and used to marinate meat. Miso is sometimes added to peanut butter or other spreads and can be combined with garlic to give garlic bread a zesty twist.

The type of miso that you have on hand may make a difference in how you use miso. Miso blends differently depending on how it is made. The most common type of miso, sweet miso, has the mildest flavor and blends well with other foods.

If you're new to using miso, this is the best type to start with. Once you get comfortable with it, experiment with other types of miso, and get creative in the kitchen to add umami to your favorite dishes.