The effects of nattokinase on the kidneys are not direct and the supplement is not recommended as a renal support tool. Instead, it can have positive effects on cholesterol levels, peripheral artery disease, cardiovascular health, and general artery and vein health, all of which support and improve kidney function. Hypertension has a negative effect on the kidneys by damaging the arteries close to the kidneys, limiting essential blood flow to the area. When nattokinase improves hypertension, it effectively improves the chance of maintaining healthy kidneys. Nattokinase is considered a useful supplement for lung, heart and hypertension diseases, specifically because its mechanisms of action attack blood thickening and, subsequently, high blood pressure.
The health benefits of nattokinase focus on the heart, and clinical trials determined that plasminogen in blood clots was effectively converted to plasmin, thus dissolving the clot and helping to prevent thrombosis. The International Journal of Molecular Sciences has demonstrated that nattokinase prevents chronic heart disease. Homemade natto has not been evaluated to the same extent as nattokinase or its store-bought fermented food counterparts, and therefore may not produce the same effects or benefits as natto produced more specifically or regulated more comprehensively. Recent studies have reported the possible anticoagulant and antihypertensive effects of nattokinase administration in humans, with no evidence of adverse effects.
Nattokinase is primarily known for its ability to improve blood pressure and overall heart health, both in human and animal studies. The consumption of nattokinase through natto itself can have a similar effect on blood circulation and fibrinogen levels, although dietary supplements provide a therapeutic-level dose and food doses may be more difficult to quantify. While nattokinase doesn't increase blood pressure, it may not be suitable for people with high blood pressure, if those people have high blood pressure or need to have surgery soon. Nattokinase can be a safe anticoagulant, as it doesn't have the same negative side effects as many pharmaceutical anticoagulants.
Natto itself contains the proteolytic enzyme and the fibrinolytic enzyme related to improving health, and can be consumed instead of taking a nattokinase supplement. Nattokinase is a fibrinolytic enzyme involved in the fermentation of soybeans to turn them into the popular Japanese food natto. Nattokinase is considered the natural anticoagulant and positive cardiovascular effects have been documented in clinical settings. In general, nattokinase acts as a blood pressure lowering agent, making it potentially dangerous for people with already low blood pressure or for people with blood clotting disorders.
To get a general idea of what to expect, this study determined that the fibrinolytic activity of nattokinase took between 2 and 8 hours to materialize. While most nattokinase research studies focus on its ability to protect the heart, nattokinase offers other health benefits, including improving metabolism and strengthening intestinal health and of the intestinal tract.
