Nattokinase is a natural enzyme derived from a traditional Japanese food that has gained attention for its potential cardiovascular benefits, particularly in managing high blood pressure, or hypertension. Researchers are investigating its role as a dietary supplement for improving blood flow and overall circulatory health. Exploring the specific biological mechanisms and clinical research findings can clarify the extent to which nattokinase may serve as a supportive agent for maintaining healthy blood pressure levels. This analysis details the enzyme’s origin, how it interacts with the circulatory system, and the current scientific consensus on its use for blood pressure reduction.
Defining Nattokinase and Its Origin
Nattokinase is a potent enzyme produced during the fermentation of soybeans, which creates the traditional Japanese food natto. The bacterium Bacillus subtilis var. natto secretes the enzyme into the fermented soybeans. Natto has been a part of the Japanese diet for centuries and is associated with various health benefits.
The enzyme is classified as an alkaline serine protease (EC 3.4.21.62), which cleaves peptide bonds in proteins. While natto contains other compounds, nattokinase is the purified component isolated and concentrated for use in dietary supplements.
How Nattokinase Influences Circulation
The primary mechanism by which nattokinase supports blood pressure regulation is through direct fibrinolytic activity. The enzyme breaks down fibrin, the protein that forms the meshwork of blood clots, helping to dissolve existing clots and prevent new ones. By promoting fibrin breakdown, nattokinase reduces blood viscosity, allowing blood to flow more easily through the vessels.
Nattokinase also influences the body’s natural blood pressure control systems by inhibiting the Angiotensin-Converting Enzyme (ACE). ACE typically converts angiotensin I into angiotensin II, a powerful vasoconstrictor that narrows blood vessels and increases pressure. Inhibiting ACE helps prevent this vessel narrowing, similar to a common class of prescription blood pressure medications.
The enzyme contributes to smoother circulation by exhibiting antiplatelet activity, reducing the aggregation of platelets involved in clot formation. Furthermore, nattokinase may inactivate Plasminogen Activator Inhibitor 1 (PAI-1), which suppresses the body’s natural clot-dissolving ability. This multi-faceted action improves blood flow and reduces resistance within the circulatory network.
Clinical Evidence for Blood Pressure Reduction
Multiple human clinical trials, including randomized controlled trials (RCTs), have investigated nattokinase supplementation in individuals with elevated blood pressure. These studies suggest nattokinase can lead to modest yet statistically significant reductions in both systolic and diastolic blood pressure.
A meta-analysis of relevant RCTs found that supplementation was associated with a mean decrease in systolic blood pressure of approximately 3.45 mmHg and a mean reduction in diastolic blood pressure of about 2.32 mmHg compared to a placebo group. This small, consistent reduction suggests nattokinase can be a supportive measure, particularly for those with pre-hypertension or mild hypertension.
Achieving these modest reductions requires consistent, long-term supplementation, as benefits do not manifest after a single dose. The evidence supports nattokinase as an adjunctive or complementary therapy for hypertension management, working alongside established lifestyle and medical interventions.
Safety Profile and Usage Guidance
Nattokinase is generally well-tolerated, with a history of long-term consumption in its whole food form, natto. The recommended standard dosage is often around 2,000 Fibrinolytic Units (FU) per day, corresponding to approximately 100 milligrams of the purified enzyme.
The most significant safety consideration relates to the enzyme’s powerful anti-clotting properties. Individuals taking anticoagulant or antiplatelet medications, such as warfarin, aspirin, or clopidogrel, should use nattokinase with extreme caution or avoid it entirely. Combining nattokinase with these drugs significantly increases the risk of bleeding or bruising due to the additive blood-thinning effect.
It is crucial to discontinue nattokinase use at least two weeks before any scheduled surgical procedure, including dental work, to minimize the risk of excessive bleeding. People with known bleeding disorders or a history of hemorrhagic stroke should not use this supplement. Anyone considering supplementation, especially for managing hypertension, should first consult with a healthcare provider due to potential interactions with medications.