Nattokinase is an enzyme derived from natto, a traditional Japanese food made from fermented soybeans. Natto has been a dietary staple in Japan for centuries, valued for its unique flavor and sticky texture. Nattokinase has garnered attention for its effects on cardiovascular health, particularly blood pressure regulation. This enzyme is produced during the fermentation process when the bacterium Bacillus subtilis var. natto is added to boiled soybeans.
Understanding Nattokinase’s Action
Nattokinase influences blood pressure through several biological pathways. One primary mechanism involves its fibrinolytic activity, breaking down fibrin, a protein that forms the meshwork of blood clots. By degrading fibrin, nattokinase improves blood flow and reduces clot formation, supporting healthy blood pressure.
The enzyme also interacts with the body’s renin-angiotensin system. Nattokinase inhibits the Angiotensin-Converting Enzyme (ACE), which produces angiotensin II, a hormone that constricts blood vessels and raises blood pressure. This inhibitory action is similar to that of some prescription blood pressure medications.
Beyond its direct effects on fibrin and ACE, nattokinase may also contribute to better blood flow by reducing blood viscosity. Studies suggest it can decrease red blood cell aggregation and low-shear viscosity, leading to improved circulation.
Scientific Evidence for Blood Pressure Reduction
Clinical trials have investigated nattokinase’s effects on blood pressure, showing promising results. In a randomized, double-blind, placebo-controlled trial involving 86 participants with pre-hypertension or stage 1 hypertension, supplementation with 2,000 Fibrinolytic Units (FU) of nattokinase daily for 8 weeks led to reductions in both systolic and diastolic blood pressure. This led to reductions of about 5.55 mmHg in systolic blood pressure and 2.84 mmHg in diastolic blood pressure compared to the placebo group.
A systematic review and meta-analysis of randomized controlled trials also reported that nattokinase supplementation significantly reduced systolic blood pressure by an average of 3.45 mmHg and diastolic blood pressure by approximately 2.32 mmHg. These findings suggest a modest but statistically significant effect. Dosages of nattokinase used in studies have varied, ranging from 1,200 to 10,800 FU per day.
Some research indicates that higher doses, such as 10,800 FU per day, might be more effective in managing certain cardiovascular markers, including reducing atherosclerosis progression and improving lipid profiles. However, for blood pressure specifically, typical dosages in studies showing reductions often fall within the 2,000 FU range. Further research, including larger-scale studies, is needed to confirm nattokinase’s efficacy and establish standardized recommendations for its use in blood pressure management.
Safety Profile and Practical Considerations
Nattokinase is considered safe when consumed as part of the traditional food natto, which has been eaten for hundreds of years. However, when taken as a supplement, there are important safety aspects to consider, primarily due to its anticoagulant properties. Nattokinase may thin the blood, which can increase the risk of bleeding or bruising.
This increased bleeding risk is particularly relevant for individuals taking blood-thinning medications, such as warfarin, aspirin, clopidogrel, heparin, or ibuprofen, as nattokinase can potentiate their effects. Combining nattokinase with these medications may lead to excessive bleeding. Individuals with existing bleeding disorders, peptic ulcers, or those who have recently experienced an ischemic stroke should avoid nattokinase.
It is also advised to discontinue nattokinase supplementation at least two weeks before any scheduled surgery to minimize the risk of excessive bleeding during or after the procedure. Furthermore, nattokinase might cause blood pressure to drop too low if taken alongside other blood pressure-lowering medications. Given these potential interactions and risks, it is highly advisable to consult a healthcare professional before starting any new supplement, especially for individuals with underlying health conditions or those currently on other medications.