Natto: The Exclusive Natural Source of Nattokinase
Nattokinase, a powerful enzyme recognized for its potential cardiovascular health benefits, is not found in a wide variety of foods. A common misconception is that all fermented soy products contain this specific enzyme, but this is untrue. The sole natural and consistent food source of nattokinase is natto, a traditional Japanese dish with a distinctive sticky, pungent texture. The enzyme is a byproduct of the specific fermentation process used to create natto, differentiating it from other fermented foods.
The Fermentation Process That Creates Nattokinase
The production of nattokinase is a specific and unique biochemical process. It does not occur in unfermented soybeans or other fermented products like miso or tempeh. The process begins with boiling soybeans, which are then inoculated with a special bacterium known as Bacillus subtilis natto. This bacterial strain, traditionally found on rice straw used for fermentation, is the key ingredient responsible for producing nattokinase. The soybeans are fermented for a period, typically at a controlled temperature for 24-48 hours. During this time, the bacteria metabolize the soy proteins and produce the enzyme that gives natto its characteristic stringy, sticky consistency and potent fibrinolytic, or blood-clot-dissolving, properties.
Why Other Fermented Foods Don't Naturally Contain Nattokinase
While other fermented soy foods are healthy and beneficial, they use different starter cultures, which result in different enzymatic profiles. For instance, miso is a paste fermented with koji (Aspergillus oryzae), not Bacillus subtilis natto. Tempeh, another soy product, uses a different mold, Rhizopus oligosporus, for fermentation. These different microbial processes produce a different set of enzymes and compounds, meaning that the unique proteolytic enzyme nattokinase is not a natural component of these products. Similarly, kimchi is a fermented cabbage dish made with lactobacillus bacteria, which also does not produce nattokinase naturally. Any presence of nattokinase in these foods would require intentional inoculation with the specific Bacillus strain, which is not part of their traditional production methods.
Health Benefits of Nattokinase
The health benefits of consuming natto are largely attributed to its nattokinase content. These benefits have been observed in numerous studies and are the reason for its popularity as a health food, especially in Japan, where it's linked to increased longevity.
- Promotes cardiovascular health: The primary benefit is its ability to help dissolve fibrin, a protein involved in blood clot formation. This action can help support healthy blood flow and reduce the risk of serious cardiovascular events.
- Supports healthy blood pressure: Research suggests that nattokinase may help lower blood pressure, which is a major risk factor for heart disease. It is thought to work by inhibiting the angiotensin-converting enzyme (ACE).
- Potential anti-inflammatory properties: Studies have also explored the anti-inflammatory effects of nattokinase, suggesting it may help mitigate age-related inflammation.
- Enhances gut health: As a fermented food, natto is rich in probiotics and prebiotic fiber, which promote a healthy gut microbiome, further supporting overall health.
Comparison of Fermented Soy Products
To illustrate the unique position of natto, here is a comparison of common fermented soy products and their relationship to the nattokinase enzyme.
| Feature | Natto | Miso | Tempeh |
|---|---|---|---|
| Primary Microorganism | Bacillus subtilis natto | Aspergillus oryzae (Koji) | Rhizopus oligosporus |
| Nattokinase Content | Yes (Naturally present) | No (Different fermentation) | No (Different fermentation) |
| Texture | Sticky and slimy | Thick paste | Firm and cake-like |
| Primary Uses | Eaten whole, often at breakfast | Soup base, sauce, marinades | Protein source, often fried or grilled |
| Production | Fermented boiled soybeans | Fermented soybeans and grain | Fermented whole soybeans |
Can You Get Nattokinase from Other Natural Sources?
For those who dislike the strong taste and texture of natto, the options for obtaining nattokinase from a natural food source are limited. While some research has explored finding similar fibrinolytic enzymes in other fermented foods like Chinese douchi or Korean doen-jang, none have been found to contain the specific, potent nattokinase enzyme in the same way as natto. This makes natto the single reliable food source for the enzyme. Outside of consuming natto itself, the only other route is via dietary supplements, which are produced by extracting and purifying the enzyme from natto. The traditional production method of natto is what makes it such a unique and potent source.
Conclusion
In summary, the question of what naturally has nattokinase leads to a singular answer: natto. This traditional Japanese food, created by fermenting soybeans with the Bacillus subtilis natto bacterium, is the only natural food source for this particular enzyme. The fermentation process is critical and exclusive to natto, meaning other fermented soy products like miso and tempeh do not contain nattokinase. While the distinct flavor and texture of natto may not appeal to everyone, its health benefits—particularly for cardiovascular wellness—are substantial. For those who cannot stomach the food, high-quality supplements offer a means to obtain the enzyme, but they are not a food-based source. The exclusive nature of nattokinase to natto makes this Japanese superfood a truly special and potent dietary choice. For a deeper scientific dive into the enzyme's properties, review this research from the National Institutes of Health(https://pmc.ncbi.nlm.nih.gov/articles/PMC5372539/).
