Understanding the Myth: Does Natto Thicken Blood?
The belief that natto could thicken blood is a common misconception, likely stemming from a confusion over its complex nutritional profile. In reality, the opposite is true. The sticky, fermented soybeans contain a powerful enzyme called nattokinase, which is highly prized for its fibrinolytic activity—meaning it breaks down fibrin, a protein that is the main component of blood clots. This process directly supports better blood flow and can help reduce blood viscosity, contributing to better cardiovascular health overall.
The Role of Nattokinase in Blood Health
Nattokinase is a serine protease produced by the bacterium Bacillus subtilis during the fermentation of soybeans. Its name is something of a misnomer, but its function is clear. It acts as a potent, systemic enzyme in the body with multiple mechanisms for promoting healthy blood circulation:
- Direct Fibrin Dissolution: It directly degrades fibrin, the mesh-like protein that holds blood clots together. This helps in breaking down existing clots and preventing new ones from forming.
- Enhancing the Body's Own Fibrinolytic System: Nattokinase helps activate plasminogen, which in turn produces plasmin, another enzyme that dissolves clots. It also degrades plasminogen activator inhibitor-1 (PAI-1), which further boosts the body's natural clot-busting activity.
- Anti-Platelet Effects: Some research suggests that nattokinase can reduce platelet aggregation, preventing platelets from clumping together to form clots.
This multi-pronged approach to supporting healthy blood flow is why nattokinase is often referred to as a "natural blood thinner." Its discovery in the 1980s quickly led to its recognition as a therapeutic agent for cardiovascular health, with research focusing on its potential for preventing conditions like heart attacks and strokes.
Natto vs. Nattokinase Supplements
It is important to differentiate between consuming whole natto and taking a nattokinase supplement, as the two have different effects on blood coagulation. While the active ingredient in both is nattokinase, whole natto also contains other nutrients, most notably vitamin K2.
Comparing Nattokinase Sources
| Feature | Whole Natto (Fermented Soybeans) | Nattokinase Supplements | Considerations |
|---|---|---|---|
| Nattokinase Content | Contains a good amount of nattokinase, though potency can vary. | Often concentrated and standardized in Fibrinolytic Units (FU). | Supplements offer a more consistent, measured dose of the active enzyme. |
| Vitamin K2 | Rich in vitamin K2 (menaquinone-7), which promotes blood clotting and bone health. | Many high-quality supplements are designed to be vitamin K2-free to avoid interfering with anticoagulant medications. | Vitamin K2 and nattokinase have opposing effects on clotting. Whole natto provides both. |
| Blood-Thinning Potency | The presence of vitamin K2 can slightly moderate the blood-thinning effect of nattokinase. | Without vitamin K2, the blood-thinning effect is more pronounced and predictable. | Choice depends on individual health goals and any existing medical conditions or prescriptions. |
| Other Nutrients | A probiotic superfood, also rich in fiber, protein, and other vitamins and minerals. | Typically contains only nattokinase (and sometimes other heart-healthy ingredients like OPC or ginger). | Whole natto offers a broader nutritional benefit, while supplements are targeted. |
Health Benefits Beyond Blood Thinning
The positive effects of natto extend beyond just blood viscosity. Its rich composition contributes to several aspects of overall health:
- Cardiovascular Health: Regular consumption is associated with a lower risk of death from cardiovascular diseases. It may also help lower high blood pressure by regulating blood flow and reducing arterial stiffness.
- Improved Gut Health: As a fermented food, natto provides beneficial probiotic bacteria that support a healthy gut microbiome, which is linked to a stronger immune system and better digestion.
- Bone Health: The high vitamin K2 content in whole natto is crucial for directing calcium to the bones and teeth, preventing its buildup in arteries where it can cause harm.
- Anti-inflammatory Effects: Nattokinase, along with other compounds in natto, may help combat chronic inflammation, a factor in many chronic diseases.
Important Precautions
While natto and nattokinase are widely considered safe for most healthy people, some individuals should exercise caution or avoid them entirely:
- If you are on blood-thinning medication: The most significant caution is for individuals taking anticoagulant drugs like warfarin. Combining nattokinase with these medications can amplify their effects and lead to excessive bleeding or bruising. A doctor's supervision is essential.
- Before surgery: Nattokinase should be discontinued at least two weeks before any scheduled surgical procedure, including dental surgery, to minimize the risk of excessive bleeding.
- Pregnancy and breastfeeding: There is a lack of reliable data regarding the safety of nattokinase during pregnancy and breastfeeding, so it is recommended to avoid supplementation during these times.
- Blood disorders: People with bleeding disorders like hemophilia should avoid nattokinase as it could worsen their condition.
Always consult a healthcare provider before adding nattokinase supplements to your regimen, especially if you have an existing health condition or take other medications.
Conclusion: Does Natto Thicken Blood?
To definitively answer the question, no, natto does not thicken blood. The available scientific evidence overwhelmingly points to the contrary, highlighting natto's potential to thin the blood and improve cardiovascular health through the enzyme nattokinase. By dissolving fibrin and supporting the body's natural fibrinolytic processes, nattokinase can help prevent and even dissolve existing blood clots. However, due to its powerful effects, particularly when in supplement form, it is crucial to understand the distinction between whole natto and nattokinase supplements and to seek medical advice if you are on any anticoagulant medication or have a pre-existing bleeding disorder. Embracing natto can be a powerful and natural way to support your heart and blood circulation, but it should be approached with knowledge and proper medical guidance.
For more detailed scientific information on nattokinase, refer to resources such as Nattokinase: An Oral Antithrombotic Agent for the Prevention of Cardiovascular Diseases.
