The Super Enzyme Nattokinase

There probably is more than one way to skin a cat, but why would you do that in the first place? What do you do with the pelt, make a coat? or the flesh? Stew? Nah. Still there is more than one way to approach a job and to get it done. This philosophy applies to healthcare as well as to mechanical tasks. Long before there was what we now call conventional medicine, there was folk medicine, which today falls into the category of integrative, or complementary, or alternative medicine. To the surprise, and even chagrin, of the orthodox model, some of these folk remedies actually work—and they do so without side effects or contraindications. Take honey, for example. It’s been around since prehistory and has been used to ease sore throats and upper respiratory troubles since then. And…it’s making a comeback (Cohen, 2012) (Paul, 2007) (Fashner, 2012).

One of the Creator’s gifts to mankind is derived from a cultural food called natto, a traditional Japanese comestible made by fermenting boiled soybeans with Bacillus subtilis, a type of soil bacterium commensal to the human gut. This bacterial strain is noted for contributing to a healthy microflora and for enhancing the status of vitamin K2. The product extracted from natto is called nattokinase, an enzyme that is able to break the peptide bonds in proteins (Fujita, 1993) using a biochemical activity resembling trypsin, which is a proteolytic enzyme made by the pancreas to separate proteins into amino acids. Despite its name, nattokinase is not a kinase enzyme. That is a catalyst in phosphorus-related functions. Instead, it’s a subtilisin enzyme, as its name suggests. Because it can break apart proteins, it exhibits potent fibrinolytic characteristics (Fujita, 1993) (Sumi, 1987), hence its use in complementary and alternative medicine as a clot-buster. The term “fibrinolytic” means that a substance is able to liquefy coagulated blood by dissolving fibrin, the elastic, stringy protein that forms a kind of mesh to attract and hold platelets to make a clot. This is an activity we want when cut, but not inside a blood vessel.

People have used nattokinase to attend to cardiovascular matters, including stroke, angina, deep vein thrombosis, atherosclerosis, intermittent claudication, and even hemorrhoids and varicose veins. (Cesarone, 2003) (Fujita, 1993). Because of its fibrinolytic activity at the blood vessel wall, where a thrombus is likely to form, nattokinase is thought to be helpful in treating atherosclerosis (Suzuki, March 2003; July 2003).

Although nattokinase is not to be taken with aspirin or other blood thinners, including fish oil (separate by a two-hour window), it works differently. Aspirin inhibits an enzyme known as cyclo-oxygenase (COX). COX activates a chemical called thromboxane A2, which makes platelets stick together to form a plug over a damaged area of a blood vessel, as in a shaving nick. The work of aspirin cannot be undone because it lasts as long as a platelet is alive and working, about a week (Roth, 1975). This makes us wonder why aspirin is recommended every day instead of only once—or maybe twice—a week.  Clots are aggregates of platelets, red blood cells and fibrin. If a clot stays still, it’s a thrombus; if it moves, it’s an embolus. Nattokinase works by removing fibrin from the equation; aspirin prevents stickiness of platelets.

As promising as nattokinase can be, it is not without its critics—a common element with alternatives to allopathic medicine. There have been no definitive outcomes regarding this agent as an alternative to conventional treatments using aspirin, clopidogrel (Plavix) or warfarin (Coumadin). One factor is the dissolution and bioavailability of nattokinase. The effects of gastric acid on nattokinase are unknown, but the enteric coated form, at 1.3 grams three times a day, seems to increase measures of fibrinolytic activity for up to eight hours after ingestion (Sumi, 1990).

When fibrin accumulates in blood vessels, it almost always causes thrombosis, possibly leading to a cardiac event. You see, this is a property of wound healing. Insults to an arterial wall, as from chronic inflammation, reactive oxygen species or illness, may hasten the inflammatory cascade that demonstrates the activation of platelets and the eventual formation of plaque-producing macrophages, all in the name of damage repair. This is where anti-inflammatory agents and anti-oxidants get their celebratory publicity…and it isn’t mere hype. This also is where nattokinase gains attention as a potential functional food additive (Peng, 2005).

If arteries are clear, and if blood has the proper viscosity, elevated blood pressure will likely be a non-issue, but this appears to be more rare than common. At Yonsei University’s Institute of Science for Ageing, in Seoul, Korea, researchers wondered about the relevance of nattokinase to blood pressure homeostasis. Studying untreated hypertensive subjects, they found that 2000 fibrinolytic units (FU)—about 100 mg—of nattokinase for eight weeks effected a drop of almost 6 points in both diastolic and systolic readings (Kim, 2008). A similar finding was reported by the pharmacology department of Hiroshima University, in Japan, a few years later (Fujita, 2011). To add feathers to the cap, nattokinase activity may parallel that of the ACE inhibitors  commonly prescribed to treat hypertension (Murakami, 2012).

More study on this fermented soybean product is needed, but its future is promising. Nattokinase does not interact with any foods and does not interfere with blood tests. It should be avoided by pregnant women for lack of safety studies. Those scheduled for surgery are admonished to discontinue using nattokinase, or any other blood-thinning agent, a couple of weeks beforehand. But we’ll leave on an encouraging note:  nattokinase may have a place in Alzheimer’s treatment as a degradation agent for amyloid fibrils (Hsu, 2009).

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