Food traditions often tell stories that extend far beyond taste. They reflect geography, climate, craftsmanship, and the knowledge passed down through generations. In Japan, few foods embody this layered history as distinctly as natto—a fermented soybean preparation known for its bold character and long-standing cultural presence. Within natto, a compound known as Nattokinase has drawn modern attention, offering a contemporary entry point into a food practice shaped by time and tradition.

Natto Within Japanese Food Culture

Natto has been part of Japanese cuisine for centuries. Made by fermenting cooked soybeans with a specific bacterial culture, it is easily recognized by its sticky texture, pronounced aroma, and deeply savory profile. Traditionally eaten with rice, natto is often served simply, allowing its natural characteristics to take center stage. While it may be unfamiliar to some, in Japan it has long been appreciated as an everyday food rather than a novelty.

The Fermentation Process

At the heart of natto is fermentation—a method that has played a vital role in food preparation across cultures. Before refrigeration, fermentation offered a way to preserve foods, but it also introduced complexity and depth. Over time, fermentation became as much about refinement as necessity. In Japan, this process reflects a broader culinary philosophy that values patience, precision, and respect for natural transformation.

How Nattokinase Appears Within Natto

Nattokinase is a specific enzyme produced during the fermentation of soybeans. While the "kinase" in its name might sound technical, it is actually a protease—a type of enzyme that specializes in breaking down proteins. Nattokinase is not present in raw soybeans. It only appears when the soybeans undergo this transformation.

Through fermentation, foods gradually change in composition. Microorganisms interact with raw ingredients, giving rise to new textures, aromas, and compounds. Natto is a clear example of this transformation. As soybeans ferment, their structure evolves, resulting in characteristics that are both sensory and compositional. It is within this process that Nattokinase was identified—an enzyme that forms as a result of natto’s unique fermentation.

Understanding the Supplement Label: What is "FU"?

When looking at Nattokinase, you will notice a measurement unlike standard vitamins. Instead of milligrams (mg), the strength is measured in FU (Fibrinolytic Units). Unlike measuring the physical weight of a powder, FU describes enzymatic activity. It measures how effectively the enzyme interacts with proteins, ensuring that the focus remains on the quality of the compound rather than just its mass.

From Everyday Food to Broader Interest

Nattokinase forms during fermentation, closely tied to the traditional preparation of natto. Its presence is inseparable from the method used to create natto, underscoring how food processes can give rise to components that later become subjects of focused interest. In this way, Nattokinase serves as a reminder that many modern ingredient conversations begin not in laboratories, but in kitchens shaped by history.

As global food culture continues to expand, traditional foods like natto are increasingly viewed through a modern lens. Busy schedules, shifting eating habits, and growing curiosity about ingredient origins have all contributed to renewed interest in heritage practices. 

Continuity Between Tradition and Contemporary Use

Looking back at natto is also a way of looking forward. It invites reflection on how food knowledge develops over time, and how long-standing practices continue to shape present-day perspectives. In a world that often moves quickly, natto stands as an example of patience and process.

As always, talk to your doctor before taking any Nattokinase supplements. Get professional advice if you think you might need any supplement or are already taking one to ensure you’re not exceeding the amounts you may need.