Evidence Level
Natto / Vitamin K2 (for Arteries)
The cardiovascular benefits of vitamin K2 and nattokinase have been extensively studied through epidemiological, interventional, and randomized controlled trials. The Rotterdam Study by Geleijnse et al. (2004) demonstrated a significant inverse relationship between dietary menaquinone intake and the risk of coronary heart disease in 4807 participants, with higher intake associated with reduced mortality rates.
Knapen et al. (2015) conducted a double-blind randomized clinical trial involving 244 postmenopausal women, showing that MK-7 supplementation over three years significantly reduced arterial stiffness, particularly in individuals with higher baseline measurements. This highlights vitamin K2's role in long-term structural protection against cardiovascular calcification.
In contrast, Kurosawa et al. (2015) investigated the effects of nattokinase in a double-blind, placebo-controlled crossover study with 12 healthy males. Results indicated that a single oral dose of nattokinase enhanced fibrinolysis and anticoagulation within normal physiological ranges, underscoring its role in improving blood flow dynamics.
Together, these studies suggest that vitamin K2 and nattokinase offer complementary benefits for arterial health: K2 mitigates calcification through structural protection, while nattokinase enhances clot dissolution and circulation. Their combined use provides a comprehensive approach to cardiovascular wellness.