Cardiovascular Health Benefits of Natto
Natto consumption, particularly due to its nattokinase content, offers cardiovascular benefits through fibrinolytic, antithrombotic, antihypertensive, and anti-inflammatory mechanisms, with epidemiological evidence showing reduced CVD mortality associated with fermented soy foods like natto. 1
Evidence from Guidelines
The most recent and authoritative guideline evidence comes from the 2022 Cardiovascular Research dietary recommendations for atherosclerosis prevention, which specifically addresses natto:
A reduction in coronary heart disease (CHD) and cardiovascular disease (CVD) mortality is associated with consumption of fermented soy foods like natto and miso, though results are not fully concordant across all meta-analyses. 1
Legumes overall (including soy products) show an inverse relationship with CHD incidence, with the largest risk reduction (-14%) observed at 400g per week consumption. 1
The beneficial association appears stronger specifically for fermented soy products compared to non-fermented soy products. 1
No dose-response data are currently available for natto specifically, which represents a gap in the evidence. 1
Context Within Broader Dietary Patterns
Fermented foods generally demonstrate beneficial cardiovascular effects, possibly due to probiotic activity that improves intestinal flora and reduces chronic disease risk. 1
Probiotics have antioxidative, anti-platelet aggregation, and anti-inflammatory properties and may lower cholesterol and blood pressure. 1
Soy protein itself has minimal direct cardiovascular benefit according to the 2006 American Heart Association advisory, which found that very large amounts of soy protein may lower LDL cholesterol by only a few percentage points. 1
The cardiovascular benefits of natto appear to derive from the fermentation process and nattokinase production rather than soy protein content alone. 1
Mechanisms of Action from Research Studies
While guidelines provide the framework, research studies illuminate the specific mechanisms:
Nattokinase possesses potent fibrinolytic (blood clot dissolving) activity, which is the primary mechanism for cardiovascular protection. 2, 3
Additional cardiovascular effects include antihypertensive, anti-atherosclerotic, lipid-lowering, antiplatelet, and neuroprotective properties. 2, 4
Nattokinase demonstrates anti-inflammatory and antioxidant effects that can mitigate molecular pathways related to oxidative stress in cardiovascular disease. 4
Peak serum levels of nattokinase occur approximately 13.3 hours after oral ingestion, with detectable levels persisting for 24 hours, confirming systemic bioavailability. 5
Nattokinase is currently undergoing Phase II clinical trials in the United States for atherothrombotic prevention. 3
Practical Recommendations
Include fermented soy foods like natto in your dietary pattern as part of a comprehensive approach to cardiovascular disease prevention, particularly if you have thrombotic risk factors. 1
Dosing Context
Traditional natto consumption in Japan has been associated with reduced CVD mortality in epidemiological studies. 2, 3
Research studies have used nattokinase supplements at 2000 FU (fibrinolytic units) as a single daily dose, though this represents extracted enzyme rather than whole food consumption. 5
The optimal dose and frequency of natto consumption for cardiovascular benefit has not been established in clinical trials. 1
Important Caveats
The evidence for natto specifically is less robust than for other dietary interventions like nuts, vegetables, and whole grains, which have stronger and more consistent cardiovascular benefits. 1
Natto should be considered as part of a broader plant-based dietary pattern rather than a standalone intervention. 1
The American Heart Association's 2000 guidelines recommend at least two servings of fish per week for omega-3 fatty acids, which have stronger evidence for cardiovascular protection than fermented soy. 1
Patients on anticoagulant therapy should exercise caution with natto due to its fibrinolytic activity, though specific contraindications have not been established in guidelines. 2, 3
Common Pitfalls to Avoid
Do not rely on natto as a replacement for evidence-based cardiovascular medications (statins, antihypertensives, antiplatelet agents). 2, 4
Do not assume all soy products provide the same benefits—the fermentation process appears critical for cardiovascular effects. 1
Do not expect dramatic lipid improvements from soy protein alone, as the American Heart Association found minimal effects on HDL, triglycerides, or blood pressure from soy protein. 1