Nattokinase for Atherosclerosis and Plaque

Introduction

For patients with subclinical cardiovascular disease, the question of whether nattokinase can affect plaque burden carries particular significance. The theoretical appeal is substantial: an enzyme that dissolves fibrin might also influence the progression of atherosclerosis, potentially offering an alternative or adjunct to conventional therapies. The reality proves more complicated.

This article examines the evidence for nattokinase effects on atherosclerosis and plaque. It addresses whether nattokinase affects plaque burden, whether it can stabilize or regress existing plaque, how it performs against proven therapies, and what imaging modalities have been used to assess these endpoints. The central finding is sobering: the most rigorous trial conducted to date found no benefit for atherosclerosis progression.

Understanding this evidence requires familiarity with nattokinase fundamentals and the broader cardiovascular evidence. For patients considering nattokinase alongside conventional medications, the drug interactions article addresses safety considerations.

Is there evidence nattokinase affects plaque burden or composition?

The evidence comes from three sources: animal studies, human imaging trials, and observational data. Animal research demonstrates that dietary natto supplementation suppresses intimal thickening after endothelial injury in rat models. More recent work in LDL receptor-deficient mice suggests natto consumption may suppress atherosclerotic plaque progression, though this study attributed effects partly to vitamin K2 rather than nattokinase alone (Suzuki et al., 2003; Kawamata et al., 2023).

Human trial data presents a more cautious picture. The Nattokinase Atherothrombotic Prevention Study randomized 265 participants without clinical cardiovascular disease to receive nattokinase or placebo for three years. The primary endpoint was change in carotid artery intima-media thickness, a validated imaging biomarker of subclinical atherosclerosis. The trial found no significant difference between nattokinase and placebo for CIMT progression (Hodis et al., 2021).

A smaller Chinese trial compared nattokinase directly to simvastatin over 26 weeks using carotid ultrasound. Both arms showed reductions in plaque size, though simvastatin produced superior lipid changes. This trial lacked a placebo arm, making it impossible to determine whether nattokinase outperformed natural variation (Ren et al., 2017).

Can nattokinase stabilize or regress existing plaque?

No trial has demonstrated plaque regression with nattokinase using validated imaging endpoints. The mechanistic rationale for such an effect is also weaker than for fibrinolysis. Atherosclerotic plaque is not primarily composed of fibrin. It consists of lipid-laden macrophages, smooth muscle cells, calcification, and extracellular matrix components. Nattokinase’s fibrinolytic activity would not be expected to dissolve these structural elements.

The NAPS trial specifically assessed whether nattokinase slowed atherosclerosis progression rather than inducing regression. Even this more modest goal was not achieved. After three years of supplementation, CIMT progression rates were essentially identical between nattokinase and placebo groups. Carotid artery stiffness, a secondary endpoint, also showed no difference (Hodis et al., 2021).

A retrospective Chinese study of 1,062 participants taking high-dose nattokinase reported favorable outcomes for atherosclerosis management, but retrospective designs cannot establish causation. Patients choosing nattokinase may differ systematically from those who do not, and without randomization these confounders cannot be controlled (Chen et al., 2022).

Does it affect calcified vs. soft plaque differently?

No clinical trial has evaluated differential effects of nattokinase on calcified versus soft plaque composition. The imaging modalities used in nattokinase research have been limited to B-mode ultrasound for CIMT measurement, which provides information about intimal thickness but cannot characterize plaque composition in detail.

The theoretical question has biological plausibility. Soft, lipid-rich plaques are considered more vulnerable to rupture than stable, calcified lesions. If nattokinase preferentially affected one type over another, this would have important clinical implications. However, answering this question would require advanced imaging such as intravascular ultrasound, optical coherence tomography, or coronary CT with plaque characterization, none of which have been employed in nattokinase trials.

Animal studies provide some suggestive but indirect evidence. Work in cholesterol-fed rabbits showed that nattokinase reduced aortic plaque area, though plaque composition was not analyzed (Kang et al., 2014). Translating these findings to human coronary atherosclerosis requires caution given differences in species, diet, and disease pathophysiology.

What imaging modalities have been used to assess plaque outcomes?

Carotid ultrasound for intima-media thickness measurement has been the predominant imaging approach. CIMT is well-validated as an epidemiological marker of cardiovascular risk, but its utility as a treatment endpoint has been questioned. Several drugs that successfully lowered CIMT in trials subsequently failed to reduce cardiovascular events in outcomes studies.

The NAPS trial used standardized ultrasound protocols with centralized reading to minimize measurement variability. This methodological rigor increases confidence in the negative finding. The trial also measured carotid artery stiffness using pulse wave velocity, providing additional vascular function data (Hodis et al., 2021).

No nattokinase trial has employed coronary CT angiography, intravascular ultrasound, or other modalities that directly visualize coronary plaque. This represents a significant limitation because carotid and coronary atherosclerosis, while correlated, do not always progress in parallel. A patient’s primary concern is typically coronary disease leading to heart attack, not carotid disease leading to stroke.

How does the plaque evidence compare to statins or PCSK9 inhibitors?

The comparison is stark. Statins have been evaluated using IVUS in trials demonstrating actual plaque regression. ASTEROID showed that high-intensity rosuvastatin reduced percent atheroma volume measured by intravascular ultrasound. SATURN demonstrated similar findings. These regression trials were then validated by large outcomes studies showing reduced heart attacks, strokes, and cardiovascular death.

PCSK9 inhibitors have similarly been evaluated with intravascular imaging. GLAGOV demonstrated plaque regression with evolocumab using IVUS in patients already on statins. The evidence progression from mechanistic studies to imaging trials to outcomes trials follows a logical development pathway that has not occurred for nattokinase.

The nattokinase evidence remains at an early stage. Animal studies show plausible effects. The single rigorous human imaging trial was negative. No outcomes trial exists. For patients deciding between nattokinase and proven therapies, this evidentiary gap is critical. Nattokinase cannot be considered equivalent to statins or PCSK9 inhibitors for atherosclerosis based on available data (Chen et al., 2018).

Conclusion

The evidence for nattokinase effects on atherosclerosis is disappointing relative to mechanistic expectations. Animal studies suggest potential benefits, but the NAPS trial found no effect on CIMT progression in humans over three years. No imaging trial has demonstrated plaque regression. The comparison to statins and PCSK9 inhibitors, which have both imaging and outcomes trial support, highlights the limitations of current nattokinase evidence.

For patients with subclinical atherosclerosis, these findings argue against using nattokinase as a substitute for proven therapies. Whether nattokinase might provide additive benefit when combined with guideline-directed medical therapy remains unknown. The blood pressure effects represent a potentially more promising endpoint, though the evidence there also has significant limitations.