Nattokinase is an serine proteinase enzyme extracted and purified from the Japanese food called nattō. 1 Nattō is produced by taking boiled soybeans and fermenting them with the bacterium Bacillus subtilis var. natto.
Figure 1. Natto
Nattokinase is produced by the bacterium acting on the soybeans.
Figure 2. Crystal structure of nattokinase from Bacillus subtilis natto. (Source)
Nattokinase exhibits a strong fibrinolytic (fibrinolysis) activity. 2 Fibrinolysis is a process that prevents blood clots from growing and becoming problematic. In the process of fibrinolysis, a fibrin clot, which is the product of coagulation, is broken down and then cleared by the kidneys and liver.
A research study from 2009 and published in the Journal of Agriculture and Food Chemistry showed that nattokinase may be effective in breaking down toxic amyloid fibrils associated with Alzheimer’s disease. 3
The study’s authors noted that
“[t]his amyloid-degrading ability of nattokinase suggests that it may be useful in the treatment of amyloid-related diseases,” particularly as “[p]revious results in rats, dogs and humans have suggested that nattokinase can enter the circulation when taken orally.”
Figure 3. Nattokinase breaking amyloid fibrils (Source)
The authors cautioned that their results were preliminary, and made the following suggestion:
“[S]ince natto has been ingested by humans for a long time, it would be worthwhile to carry out an epidemiological study on the rate of occurrence of various amyloid-related diseases in a population regularly consuming natto.”