Common Names
- Natto extract
- Fermented soybeans
For Patients & Caregivers
How It Works
Nattokinase may help prevent clot formation and reduce blood pressure. It has not been tested as a cancer treatment in humans.
Nattokinase is an enzyme produced from nattō, a traditional Japanese food made from soybeans fermented with the bacterium, Bacillus subtilis. It can break down fibrin in the blood that forms clots. Studies in humans suggest that nattokinase can reduce high blood pressure and may benefit patients with Alzheimer’s disease. Although nattokinase has been promoted as an alternative anticancer treatment, clinical studies have not been conducted to show that it is effective.
Nattokinase may increase the risk of bleeding in patients when used with “blood thinning” drugs.
Purported Uses
- Antithrombotic
A few studies have shown that nattokinase has the ability to prevent deep vein thrombosis. - Hypertension
Nattokinase has been shown in clinical studies to reduce hypertension. - Alzheimer’s disease
Studies using animal models have shown that nattokinase can degrade amyloid plaques. Human studies have not been conducted. - Cancer treatment
Although nattokinase is promoted as an alternative cancer treatment, clinical data of its effectiveness are lacking.
Patient Warnings
Do Not Take If
For Healthcare Professionals
Clinical Summary
Nattokinase is an extracelluar enzyme secreted by the bacterium Bacillus subtilis, used to ferment boiled or steamed soybeans resulting in a preparation called nattō. Nattō has been consumed as food in Japan for several centuries. Nattokinase is also available as a supplement and is most known for its fibrinolytic and thrombolytic effects.
A few studies have explored its antihypertensive and amyloid-plaque degrading abilities (1) (2) (3) (4) (5). Nattokinase decreases platelet aggregation and thrombus formation in a dose-dependent fashion both in vitro and in vivo (6) (7). Reduced intimal thickening was observed in the femoral artery of rats that were fed a diet containing nattō (8).
In a randomized, double-blind, placebo-controlled human trial, nattokinase capsules reduced diastolic and systolic blood pressure in pre-hypertensive patients (3). The observation that nattokinase degrades amyloid plaques (1) (9) led to an interest in exploring it as a treatment for Alzheimer’s disease, which is characterized by accumulation of amyloid plaques.
Nattokinase has also been promoted as an alternative anticancer treatment based on the notion that it can help dissolve the fibrin coating around a tumor, and increase oxygen supply in the blood to inhibit cancer cell growth. However, these mechanisms have not been proven in humans.
Theoretically, nattokinase may increase bleeding risk when used with anticoagulant, antiplatelet, and fibrinolytic drugs. Raw nattō contains high levels of vitamin K that may interfere with the action of warfarin (15).
Mechanism of Action
In vitro studies show that nattokinase decreases clot formation by cleaving and inactivating the plasminogen activator inhibitor (PAI) via proteolysis at P1-P1’ peptide bond. PAI is a key inhibitor of tissue plasminogen activator (tPA) that converts plasminogen to plasmin. PAI inactivation allows for greater tPA activity and increased lysis of clots (10) (11). In the absence of PAI, nattokinase affects direct proteolysis of fibrin; however, this effect is less than the protelysis achieved by the PAI-mediated pathway (2). The fibrinolytic activity of nattokinase is estimated to be four fold that of plasmin (12).
Nattokinase is currently being evaluated for its potential as an amyloid plaque-degrading agent. Low doses of nattokinase have been shown to increase expression of the ADAM10 gene, which belongs to a family of proteinases that degrade the amyloid precursor protein (APP). The upregulation of ADAM10 may shift the amyloidogenic pathway to the non-amyloidogenic pathway. This activity may be used as a method to prevent amyloid plaque accumulation that characterizes Alzheimer’s disease (9).
Warnings
Theoretically, nattokinase can cause an existing clot to dislodge due to its fibrinolytic property, resulting in a stroke or embolus at a distal location. Patients with a history of deep vein thrombosis should avoid of use nattokinase (5).
Contraindications
Herb-Drug Interactions
- Aspirin: Nattokinase may increase the risk of intracerebral hemorrhage (14).
- Anticoagulant/antiplatelet/fibrinolytic drugs: Theoretically, nattokinase may increase the risk of bleeding.
- Warfarin: Nattō is rich in vitamin K. In addition, Bacillus subtilis bacteria in natto continue synthesizing vitamin K in the intestine following consumption, which can reduce the effects of warfarin (15).