Nattokinase is an enzyme that has garnered significant attention for its potential role in cardiovascular wellness, particularly regarding arterial hardening. Derived from a traditional fermented food, it is widely studied for its effects on blood flow and clot management. The primary question is whether it can actively “clean” arteries by dissolving existing plaque buildup, a condition known as atherosclerosis. This article will examine the scientific evidence.
The Origin and Function of Nattokinase
Nattokinase is a potent enzyme isolated from natto, a pungent, sticky food made from soybeans fermented with the bacterium Bacillus subtilis. This traditional Japanese food has been consumed for centuries, but the enzyme itself was first isolated and named in 1987 by Dr. Hiroyuki Sumi, who discovered its ability to rapidly dissolve artificial blood clots.
The fundamental function of nattokinase is its powerful fibrinolytic activity, meaning it directly breaks down fibrin, the protein that forms the mesh structure of a blood clot. It also enhances the body’s natural clot-dissolving mechanisms by activating tissue plasminogen activator (tPA), which converts plasminogen into plasmin. This established biological action is why the enzyme is frequently investigated for its general effects on blood viscosity and circulation.
Scientific Evidence Regarding Arterial Plaque Reduction
The term “cleaning arteries” suggests the complete dissolution of established atherosclerotic plaque, which is a complex mixture of cholesterol, fibrous tissue, and calcium deposits. While nattokinase is effective at breaking down the fibrin component found within blood clots and some soft plaque, the challenge lies in its ability to regress the calcified, hardened portions of long-standing plaque. Research, however, offers compelling evidence regarding its anti-atherosclerotic effects, primarily by slowing the progression of plaque and reducing its overall size.
Clinical trials have monitored the effects of nattokinase on the common carotid artery intima-media thickness (IMT) and plaque area, common markers for atherosclerosis. In a study of patients with existing atherosclerotic plaques, supplementation with nattokinase showed a significant reduction in both plaque size and IMT over several months. Specifically, one study reported that a high daily dose of 6,000 Fibrinolytic Units (FU) resulted in a 36.6% reduction in carotid plaque size over 26 weeks.
Another large study involving a daily dose of 10,800 FU demonstrated significant improvements in IMT and plaque regression. These findings suggest that nattokinase may actively contribute to the stabilization and partial regression of plaques, likely by degrading the fibrin and protein components within the lesion. Current evidence supports its role in managing the progression of the disease and reducing the overall plaque burden.
Safety Profile and Contraindications
Due to its powerful biological activity as a fibrinolytic agent, nattokinase carries significant safety considerations, particularly regarding the risk of bleeding. Because the enzyme actively works to break down fibrin, it can amplify the effects of other medications that also slow blood clotting. Individuals with pre-existing bleeding disorders should avoid taking nattokinase unless explicitly directed by a healthcare professional.
The enzyme is contraindicated for anyone taking anticoagulant drugs, such as warfarin or heparin, or antiplatelet medications, including aspirin or clopidogrel, because the combination can dramatically increase the risk of hemorrhage and bruising. Nattokinase may also interact with medications for high blood pressure, potentially causing blood pressure to drop excessively.
It is strongly advised to discontinue the use of nattokinase at least two weeks before any scheduled surgery or dental procedure to minimize the risk of excessive bleeding. Pregnant and breastfeeding women are also advised to avoid supplementation, as insufficient data exists to confirm its safety. Individuals who have recently experienced a hemorrhagic stroke or have a peptic ulcer should also avoid the enzyme due to the elevated bleeding risk.
Recommended Usage and Supplement Considerations
Nattokinase is typically measured in Fibrinolytic Units (FU), which quantifies the enzyme’s clot-dissolving strength. The standard dosage found in many supplements is around 2,000 FU per day, which is often cited for general cardiovascular support. However, clinical studies showing significant plaque reduction utilized substantially higher doses, ranging from 6,000 FU to over 10,000 FU daily.
Consumers should prioritize supplements that provide clear labeling of the FU activity and have undergone third-party testing to confirm purity and potency. Many manufacturers remove Vitamin K2 from the final product, as K2 can counteract the effects of certain blood-thinning medications like warfarin.
Given the significant contraindications and potential for drug interactions, consultation with a healthcare provider is mandatory before beginning nattokinase supplementation. A medical professional can assess an individual’s specific health status, existing medications, and overall risk profile to determine if the potential benefits outweigh the recognized safety concerns.