Jensen GS, et al. – In this current study, researchers examined the impacts of nattokinase consumption on hypertension in a North American hypertensive population with associated genetic, dietary, and lifestyle factors. This was in extension of, and contrast to, previous studies on Asian populations. In the given study population, an association was apparent, between nattokinase consumption and beneficial changes to blood pressure (BP), suggesting sex–specific mechanisms of action of nattokinase’s effect on von Willebrand factor (vWF) and hypertension.

Methods

• Researchers conducted a randomized, double-blind, placebo-controlled, parallel-arm clinical study to assess nattokinase (NSK-SD), a fermented soy extract natto from which vitamin K2 has been removed.
• Based on the results from previous studies on Asian populations, 79 subjects were enrolled upon screening for elevated blood pressure (BP; systolic BP ≥130 or diastolic BP ≥90 mmHg) who consumed placebo or 100 mg nattokinase/d for the 8-week study duration.
• They performed blood collections at baseline and 8 weeks for testing plasma renin activity, von Willebrand factor (vWF), and platelet factor-4.
• Seventy-four people completed the study with good compliance.

Results

• Findings demonstrated that consumption of nattokinase was associated with a reduction in both systolic and diastolic BP.
• According to results, the reduction in systolic BP was seen for both sexes but was more robust in males consuming nattokinase.
• Researchers observed that the average reduction in diastolic BP in the nattokinase group from 87 mmHg to 84 mmHg was statistically significant when compared to that in the group consuming placebo, where the average diastolic BP remained constant at 87 mmHg (P<0.05), and reached a high level of significance for males consuming nattokinase, where the average diastolic BP dropped from 86 mmHg to 81 mmHg (P<0.006).
• Data also revealed that a decrease in vWF was seen in the female population consuming nattokinase (P<0.1).
• Results highlighted that in the subpopulation with low plasma renin activity levels at baseline (<0.29 ng/mL/h), an increase was seen for 66% of the people after 8-week consumption of nattokinase (P<0.1), in contrast to only 8% in the placebo group.