Nattokinase (NK) is an enzyme derived from natto, a traditional Japanese food made from fermented soybeans. It has garnered attention for its potential cardiovascular benefits, particularly its influence on blood pressure. Scientific investigations have explored whether supplementing with this enzyme can effectively contribute to lowering high blood pressure. This article reviews the evidence surrounding Nattokinase’s role in blood pressure management.
Defining Nattokinase and its Source
Nattokinase is a powerful protease enzyme extracted from natto, a food created by fermenting boiled soybeans with the bacterium Bacillus subtilis natto. Natto has been included in the traditional Japanese diet for centuries. The enzyme is a serine protease, meaning it breaks down proteins.
Standardization of Nattokinase supplements is measured using Fibrinolytic Units (FU). This unit quantifies the enzyme’s potency based on its ability to break down fibrin, the primary protein component of blood clots. Measuring activity in FU provides a more accurate assessment of the product’s biological strength than a simple weight measurement. A typical suggested daily dose often contains 2,000 FU of Nattokinase.
Clinical Studies on Blood Pressure Reduction
Multiple human clinical trials and systematic reviews suggest that Nattokinase supplementation may function as an effective adjunctive therapy for managing hypertension. Meta-analyses of randomized controlled trials have shown a statistically significant, mild to moderate reduction in both systolic and diastolic blood pressure among participants.
A systematic review found that Nattokinase supplementation significantly reduced systolic blood pressure by an average of 3.45 mmHg and diastolic blood pressure by 2.32 mmHg, compared to a placebo group. These effects are most noticeable in individuals with prehypertension or mild, untreated hypertension. For example, one study documented a decrease of 5.55 mmHg in systolic pressure and 2.84 mmHg in diastolic pressure after eight weeks in participants with initial systolic blood pressure between 130 and 159 mmHg.
Beneficial changes in blood pressure are not instantaneous and typically require consistent, long-term supplementation to manifest. The evidence supports Nattokinase as a natural compound that can contribute to overall cardiovascular health by helping to regulate blood pressure.
Understanding How Nattokinase Works
Nattokinase’s ability to influence blood pressure is attributed to two main biochemical pathways. The first is that the enzyme contains unique peptides that act as an Angiotensin-Converting Enzyme (ACE) inhibitor. ACE is a protein that causes blood vessels to constrict, thereby raising blood pressure.
By inhibiting ACE, Nattokinase helps prevent the formation of angiotensin II, a powerful vasoconstrictor, allowing blood vessels to relax and widen. This action is similar to prescription ACE inhibitor medications. Furthermore, Nattokinase degradation products help prevent the elevation of plasma angiotensin II levels.
The second pathway is its fibrinolytic activity, which is the breaking down of fibrin. Nattokinase can directly hydrolyze fibrin, the protein that forms the mesh structure of a blood clot. It also supports the body’s natural clot-dissolving systems by degrading Plasminogen Activator Inhibitor-1 (PAI-1), which increases tissue plasminogen activator (t-PA) and subsequent clot lysis. Improved circulation and less viscous blood resulting from this anti-clotting effect may indirectly contribute to reduced force against artery walls.
Safe Dosing and Contraindications
The standard effective dose typically used in clinical studies is approximately 2,000 FU per day. This dosage, often equivalent to about 100 mg of the purified enzyme, has been used safely for periods up to several months.
A significant safety consideration is the enzyme’s potent anti-clotting property, which necessitates caution when combined with other medications. Nattokinase can interact with anticoagulant and antiplatelet drugs (e.g., Warfarin, Aspirin), potentially increasing the risk of excessive bruising or bleeding. Due to its effect on blood clotting, supplementation should stop at least two weeks before any scheduled surgical procedure, including dental surgery.
Nattokinase can also augment the effect of prescribed blood pressure medications, potentially causing blood pressure to drop too low. Any person managing hypertension or taking blood-thinning medication must consult with a healthcare provider before beginning supplementation.