What Is Natto? The Japanese Superfood Explained

Natto is one of Japan's most famous traditional foods, yet it remains one of the most misunderstood superfoods outside of Asia. Known for its sticky texture, powerful aroma, and impressive nutritional profile, natto has been consumed in Japan for more than 1,000 years and is increasingly recognized worldwide for its potential health benefits.

Made from fermented soybeans, natto contains a unique enzyme called nattokinase, along with probiotics, vitamin K2, protein, and other beneficial compounds. These nutrients have made natto a popular choice among people interested in heart health, healthy aging, circulation, and overall wellness.

What Is Natto?

Natto is a traditional Japanese food made by fermenting whole soybeans with a beneficial bacterium called Bacillus subtilis var. natto. During fermentation, the soybeans develop a distinctive sticky coating and stringy texture that many people instantly recognize.

Unlike tofu, miso, or soy milk, natto undergoes a specialized fermentation process that creates unique bioactive compounds not found in regular soy products.

Today, natto is commonly eaten throughout Japan, particularly as part of a traditional breakfast served over rice.

What Does Natto Taste Like?

Natto has a strong, earthy flavor often described as nutty, savory, and deeply umami. However, its most notable characteristic is its texture.

The fermented soybeans produce sticky strings when stirred, giving natto a slimy consistency that can be surprising to first-time eaters.

Many people compare the experience to foods such as strong cheeses or fermented vegetables - an acquired taste that often becomes more enjoyable with repeated exposure.

How Is Natto Traditionally Eaten?

In Japan, natto is commonly served with:

• Steamed rice

• Soy sauce

• Japanese mustard

• Green onions

• Raw egg

• Seaweed

Some people also add natto to sushi rolls, noodle dishes, grain bowls, and salads.

The History of Natto

Natto has been part of Japanese culture for centuries, with historical records suggesting it has been consumed for more than 1,000 years. 

While the exact origins remain uncertain, many historians believe natto first appeared during Japan's Heian period (794–1185), when soybeans were already an important agricultural crop.

According to popular historical accounts, natto was likely discovered accidentally when cooked soybeans were stored in straw, which naturally contains Bacillus subtilis. During transport or storage, the warm soybeans fermented naturally, creating the sticky, flavorful food now known as natto. Over time, people noticed the fermented beans developed unique flavors and health-promoting properties, leading to their widespread adoption.

As natto gained popularity, different regions of Japan developed their own preparation methods and serving traditions. The food became especially common in eastern Japan, where it remains a breakfast staple today. 

Advances in food production during the 20th century helped make natto more widely available throughout the country, transforming it from a regional specialty into a nationally recognized food.

Today, natto remains a staple food in many Japanese households and is frequently associated with longevity and healthy aging. Japan's reputation for having one of the world's longest life expectancies has sparked international interest in traditional foods like natto, which are often included in discussions about healthy dietary patterns.

Its continued popularity has helped introduce the rest of the world to one of Japan's most celebrated functional foods. 

As research into fermented foods and gut health continues to grow, natto has gained recognition not only for its cultural significance but also for its unique nutritional profile and naturally occurring compounds such as nattokinase and vitamin K2.

How Is Natto Made?

The production of natto begins with carefully selected soybeans.

The soybeans are first soaked in water and steamed until soft. They are then inoculated with Bacillus subtilis natto and placed in a controlled environment where fermentation occurs.

During fermentation, the bacteria break down proteins and carbohydrates within the soybeans, producing beneficial compounds that enhance the food's nutritional value.

After fermentation, natto is aged briefly before packaging and distribution.

Why Fermentation Matters

Fermentation transforms soybeans into a more bioavailable and nutrient-dense food.

This process can:

• Increase nutrient absorption

• Produce beneficial probiotics

• Generate vitamin K2

• Create nattokinase

• Improve digestibility

These changes are a major reason why fermented foods like natto are considered valuable additions to a balanced diet.

Natto Nutrition Facts

Natto is remarkably nutrient-dense relative to its calorie content.

A typical 100-gram serving contains:

Natto also contains numerous biologically active compounds that contribute to its reputation as a superfood.

Key Nutrients Found in Natto

• Protein: Natto provides complete plant-based protein containing all essential amino acids.

• Fiber: Dietary fiber supports digestive health and helps promote satiety.

• Vitamin K2: Natto is one of the richest known dietary sources of vitamin K2, a nutrient that plays an important role in calcium metabolism and bone health.

• Iron and Magnesium: These minerals contribute to energy production, muscle function, and overall health.

• Probiotics: As a fermented food, natto contains beneficial bacteria that may support gut health.

Top Health Benefits of Natto

1. Supports Heart Health

Natto is perhaps best known for its association with cardiovascular wellness.

The combination of nattokinase, vitamin K2, and beneficial nutrients makes natto one of the most researched foods in the heart health category.

2. Rich Source of Vitamin K2

Vitamin K2 helps direct calcium into bones and away from soft tissues where it may not belong.

Because natto contains exceptionally high amounts of vitamin K2, it is often recommended as a dietary source of this important nutrient.

3. Promotes Healthy Blood Flow

Nattokinase has been studied for its ability to support healthy circulation through its interaction with fibrin.

Maintaining healthy blood flow is important for delivering oxygen and nutrients throughout the body.

4. Supports Digestive Health

Fermented foods provide beneficial bacteria that may contribute to a healthy gut microbiome.

A balanced microbiome is associated with numerous aspects of overall health.

5. Provides High-Quality Plant Protein

Protein supports muscle maintenance, recovery, and healthy aging.

Natto offers a complete protein source suitable for many dietary preferences.

6. May Support Healthy Aging

The combination of probiotics, vitamin K2, antioxidants, and bioactive compounds makes natto a popular food among those interested in longevity and healthy aging.

Why Is Natto Associated With Heart Health?

One reason natto stands apart from other fermented foods is its nattokinase content.

To understand why, it's helpful to understand fibrin.

Fibrin is a protein involved in the body's natural clotting process. While clotting is essential for wound healing, excessive fibrin accumulation may affect healthy circulation.

Nattokinase has been studied because it helps break down fibrin and supports normal circulatory function.

Researchers continue exploring the enzyme's potential effects on:

• Blood flow

• Vascular health

• Blood pressure support

• Circulatory efficiency

This ongoing research has helped nattokinase become one of the most recognized natural enzymes in cardiovascular wellness.

Can You Get Enough Nattokinase From Eating Natto?

Many people wonder whether eating natto alone provides enough nattokinase.

The answer depends on several factors:

• Serving size

• Fermentation conditions

• Product quality

• Frequency of consumption

For individuals who eat natto regularly, it can be a valuable source of nattokinase.

However, many people face challenges including:

• Limited availability

• Strong taste

• Inconsistent enzyme levels

• Difficulty eating natto daily

As a result, some choose standardized nattokinase supplements.

Natto vs Other Fermented Foods

Not all fermented foods provide the same benefits.

Natto remains unique because it combines probiotics, vitamin K2, and nattokinase in a single food.

Are There Any Side Effects of Natto?

Natto is generally considered safe for most healthy adults and has been consumed in Japan for centuries.

However, there are some considerations.

• Soy Allergies: Individuals with soy allergies should avoid natto.

• Medication Interactions: Because nattokinase may influence blood clotting mechanisms, people taking blood-thinning medications should consult a healthcare provider before consuming natto or nattokinase supplements.

• Surgery Precautions: People scheduled for surgery should discuss nattokinase use with their physician beforehand.

• Pregnancy and Nursing: Pregnant or breastfeeding women should seek medical guidance before using nattokinase supplements.

How to Eat Natto If You're a Beginner

If you're new to natto, consider starting with small servings.

Popular beginner-friendly approaches include:

• Mixing natto into rice bowls

• Combining it with eggs and soy sauce

• Adding it to grain bowls

• Incorporating it into sushi-style dishes

Some people find that repeatedly trying natto helps them develop an appreciation for its unique flavor.

If the taste or texture remains challenging, a nattokinase supplement may offer an alternative way to obtain its signature enzyme.

Healthletic Ultimate Nattokinase: A Convenient Alternative

For people seeking the benefits of nattokinase without consuming natto every day, Healthletic Ultimate Nattokinase offers a concentrated and standardized solution.

The formula delivers a clinical-strength 10,800 FU dose of nattokinase, substantially higher than many conventional products that provide between 2,000 and 4,000 FU.

This supplement is designed to support healthy circulation by helping address fibrin buildup associated with arterial inflammation. The formula also uses delayed-release capsules intended to maximize absorption and protect the enzyme from stomach degradation.

For individuals who find natto difficult to eat consistently, supplementation may provide a more practical way to obtain a standardized nattokinase intake.

Final Thoughts

Natto is far more than a traditional Japanese food. It is a nutrient-rich fermented superfood that combines protein, probiotics, vitamin K2, and the unique enzyme nattokinase into a single functional food.

Whether you're interested in digestive wellness, healthy aging, or cardiovascular support, natto offers a compelling nutritional profile backed by centuries of traditional use and growing scientific interest. 

For those who struggle with natto's distinctive taste and texture, standardized nattokinase supplements such as Healthletic Ultimate Nattokinase provide a convenient alternative, making it easier to incorporate one of Japan's most celebrated wellness compounds into a daily routine.

Frequently Asked Questions

Is natto healthy?

Natto is considered one of the most nutrient-dense fermented foods available. It provides protein, fiber, probiotics, vitamin K2, and nattokinase.

What does natto taste like?

Natto has a strong savory flavor with earthy, nutty notes and a sticky texture.

Is natto the same as nattokinase?

No. Natto is the fermented soybean food, while nattokinase is an enzyme produced during fermentation.

Can I eat natto every day?

Many people in Japan consume natto daily as part of a balanced diet.

Does natto contain probiotics?

Yes. As a fermented food, natto contains beneficial bacteria that may support gut health.

Is natto good for circulation?

Natto contains nattokinase, an enzyme that has been studied for its role in supporting healthy blood flow and circulation.

Can I take nattokinase instead of eating natto?

Yes. Many people choose nattokinase supplements because they provide standardized doses without natto's strong taste or texture.