What Exactly Is Nattokinase?
Nattokinase is a powerful fibrin-dissolving enzyme belonging to the protease family. It is produced by the bacterium Bacillus subtilis variety natto during the fermentation of boiled soybeans into the traditional Japanese food known as natto. First isolated and named in 1987 by Japanese researcher Dr. Hiroyuki Sumi, the enzyme is responsible for natto's strong, pungent smell and its distinctive sticky, stringy consistency.
Unlike enzymes present in unfermented soybeans or other common foods, nattokinase is a unique byproduct of this specific fermentation process. While research into its full range of effects is ongoing, nattokinase is primarily studied for its potential cardiovascular benefits, including its ability to break down blood clots and support healthy blood pressure levels.
The Exclusive Dietary Source: Natto
The short answer to the question "Is nattokinase found in food?" is that it is almost exclusively found in natto. This fermented soybean dish is a staple of the Japanese diet, particularly in the eastern regions of the country. Here's why natto is the key source:
- Specific Bacterium: The production of nattokinase is dependent on the specific strain of bacteria, Bacillus subtilis var. natto, used in the fermentation process. Other forms of soy fermentation use different bacteria and do not produce this specific enzyme.
- Unique Process: Making natto involves soaking, steaming, and then carefully fermenting whole soybeans at a controlled temperature for about a day. This process creates the slimy, sticky texture that is rich in the nattokinase enzyme.
- Not in Other Soy Foods: Products like tofu, soy milk, edamame, or even other fermented soy foods like miso and soy sauce do not contain nattokinase. The enzyme is specific to the natto fermentation process.
Other Fermented Soybean Products
While natto contains the highest and most potent form of nattokinase, some other traditional fermented soybean products from East and Southeast Asia have been found to contain fibrinolytic enzymes with similar activity. These include:
- Tempeh: This Indonesian fermented soy product, made with a different starter culture (Rhizopus fungi), has been found to contain some fibrinolytic enzymes. However, the quantity and specific type of enzyme differ from nattokinase in natto.
- Douchi: A Chinese seasoning made from fermented and salted black soybeans, douchi also contains some enzymes with fibrinolytic properties.
- Cheonggukjang: This Korean fermented soy paste is also noted as a source of fibrinolytic enzymes.
These products are not considered equivalent to natto for nattokinase intake and have different flavors and textures. Standardized nattokinase supplements are typically derived from natto itself, allowing for precise and concentrated dosing.
Natto vs. Nattokinase Supplements
For those seeking the benefits of nattokinase, there are two primary options: consuming natto or taking a dietary supplement. Here is a comparison to help determine the best approach.
| Feature | Natto (Whole Food) | Nattokinase Supplement |
|---|---|---|
| Source of Nattokinase | Produced during the fermentation of whole soybeans with Bacillus subtilis var. natto. | Isolated and extracted from natto, then encapsulated or powdered. |
| Dosage Control | Variable. The amount of nattokinase can differ based on the fermentation time and process. It is difficult to measure a precise dose from a serving of natto. | Standardized. Supplements are tested to contain a specific amount of active nattokinase, typically measured in fibrinolytic units (F.U.), allowing for consistent and precise dosing. |
| Nutritional Profile | A rich source of protein, fiber, iron, manganese, and a high concentration of vitamin K2, which supports bone health. | Offers a concentrated dose of nattokinase but lacks the full nutritional spectrum found in the whole food. Some supplements remove vitamin K2 to avoid blood-clotting interactions. |
| Taste and Texture | Characterized by a pungent odor and sticky, stringy texture that can be an acquired taste for some. | Taste and texture are not factors, as the enzyme is consumed in capsules or powder form. |
| Interaction with Blood Thinners | Contains a high amount of vitamin K2, which promotes blood clotting and can interfere with anticoagulant drugs like warfarin. It is generally advised for individuals on these medications to avoid natto. | Vitamin K2 is often removed during processing to prevent interactions with blood-thinning medication. This makes it a potentially safer alternative for some, but medical consultation is still essential. |
Conclusion
To answer the question definitively, yes, nattokinase is found in food, but its presence is largely restricted to the Japanese food natto. While other fermented soy products like tempeh and douchi contain similar enzymes, natto is the unique and most concentrated natural food source of nattokinase. The distinctive fermentation process with Bacillus subtilis var. natto is responsible for generating this specific, health-promoting enzyme. For those who cannot tolerate natto's taste or texture, standardized dietary supplements derived from natto are available, offering a consistent and potent dose of the enzyme. Whether opting for the whole food or a supplement, it is crucial to consult a healthcare professional, especially for those with existing health conditions or who are taking blood-thinning medication.
