Normal blood clotting – the kind that happens to seal up a cut or to repair a ruptured blood vessel – is vital to survival. But many people suffer from excessive thrombosis, a kind of “micro-coagulation” that goes on inside your blood vessels all the time – even when you haven’t been injured.
The tiny clots (thrombi) thus formed are normally quickly digested in a process called fibrinolysis. If the balance between clot-forming and clot-dissolving activity is not maintained, thrombi can block off tiny blood vessels feeding your heart (triggering a heart attack) or brain cells (causing a stroke). Fibrin (which binds thrombi together) can also be deposited in your arteries or other tissues, contributing to atherosclerosis and leading to local starvation for oxygen and nutrients. In fact, some evidence suggests that elevated fibrinogen leading to the loss of fibrinolytic balance may actually be the most important risk factor in determining your odds of suffering a heart attack.
Dr. Hiroyuki Sumi of Japan’s Miyazaki Medical College tested 173 different natural products, looking for a natural way to support fibrinolytic activity. He initially thought he had found his solution in the earthworm enzyme lumbrokinase, but abandoned it when studies showed that lumbrokinase damages the intestinal tract, causing internal bleeding in older volunteers.
But then Dr. Sumi’s team discovered Nattokinase, a powerful fibrinolytic enzyme naturally present in natto (a traditional Japanese fermented food). Nattokinase has a fibrinolytic “potency matched by no other enzyme.”
Nattokinase Enhances Fibrinolysis
In a controlled study, Dr. Sumi’s team fed a group of twelve volunteers a large (200 gram) serving of natto, comparing its effects on two measures of fibrinolytic activity with those of unfermented cooked soybeans. Plain soybeans had no effect, but Nattokinase consumption cut the time needed to complete the clot-dissolving cycle in half. And after Nattokinase consumption, total fibrinolytic activity climbed from zero to 15.2 square millimeters by the four-hour mark
Dr. Sumi’s team next performed a longer-term study using Nattokinase tablets. For eight days, volunteers took Nattokinase and had their fibrinolytic activity assessed. Fibrinolytic activity climbed steadily over the course of the first four days of using Nattokinase, reaching a stable plateau which was maintained for the rest of the week. At the same time, markers of dissolved fibrin rose to a rapid peak and then moved toward a steady lower level. And when the scientists tested the key enzyme responsible for activating fibrinolysis in the body, tissue plasminogen activator (tPA) was boosted in men taking Nattokinase.
Nattokinase Restores Blood Flow
A further experiment by Dr. Sumi’s group showed that Nattokinase is potent enough to actually open up circulatory blockages. The team first injected a thrombotic cocktail into lab dogs’ legs, leading to a thrombus and complete blockage of the vein. One group of dogs received Nattokinase tablets, while the others got a dummy pill. An immediate boost in the fibrinolytic activity ensued in dogs receiving Nattokinase; and while the veins of dogs in the control group remained blocked off a full 18 hours after the beginning of the experiment, those receiving Nattokinase experienced a complete restoration of normal blood flow within 5 hours.
Work in humans has also been reported. In one remarkable case study, a team of researchers decided to test the ability of Nattokinase to treat a case of central retinal vein occlusion, which occurs when the blood vessels draining out of the eye are blocked by a thrombus. The occlusion had caused edema and bleeding in the eye, as the dammed-up blood vessels swelled the eye and caused tiny vessels to burst. The researchers asked the man to eat a moderately large (100 gram) serving of natto before going to bed every night as a Nattokinase source to dissolve the clot, instead of “blood-thinning” drugs like aspirin or warfarin (Coumadin®).
Ten days later, bleeding from bottom of the eye was stopped. On day twenty, the man recovered his vision, and was released from hospital with instructions to continue eating his natto (two evenings each week). Two months later, Nattokinase had completely cleared the occlusion.
A Tri-fold Balance
There are at least three separate mechanisms whereby Nattokinase exerts its pro-fibrinolytic effect. Of these three, the direct fibrinolytic action of Nattokinase, enzymatically degrading fibrin, appears to be the least important. The other two mechanisms are the cleaving of plasminogen activator-inhibitor type 1 (PAI-1) and the upregulation of conversion of prourokinase to urokinase.
By shifting the balance of key regulators of plasminogen-regulating factors, Nattokinase allows the body to rev up its natural fibrinolytic activity, while still maintaining overall regulation of fibrinolytic balance.
Boosting Fibrinolysis Naturally
Blockages of large blood vessels are rare, and require hospitalization and physician attendance. Only a fool would reach for a Nattokinase capsule if there were signs of a heart attack or stroke. But if you suffer from hypercoagulability, you may be looking to enhance your body’s fibrinolytic function. Quitting smoking, losing weight, and getting more exercise enhance fibrinolysis, while moderate alcohol consumption, fish oil, curcumin, and niacin lower fibrinogen (you may want to use “flush-free” niacin (inositol hexanicotinate), not to be confused with niacinamide).
But while lowering fibrinogen levels can help prevent excessive thrombus formation, it doesn’t address the other side of the fibrinolytic balance sheet. Nattokinase’s ability to boost your body’s own clot-busting activity makes this natural food enzyme an unique addition to your supplement armamentarium.
Potency and Purity
The most advanced Nattokinase supplements boast a remarkable 20 000 fibrinolytic activity units per gram (FU/g). Just two such capsules, containing 36 milligrams of very pure Nattokinase each, can deliver a full 1440 FU of activity. Just as important, with this new technique the fermentation medium used to produce Nattokinase contains no soy, so that the new 20 000 FU/g Nattokinase supplements are completely soy-free.
Who Should Not Take Nattokinase
Nattokinase is not a simple “blood thinner:” it works by breaking down tangled threads of fibrin, not preventing the clumping together of platelets, acting to prevent thrombosis rather than normal coagulation. Still, fibrin deposition is an important part of wound healing, and while excessive fibrin formation leading to hypercoagulability is a threat to your health, so is interfering with fibrin formation when it’s needed to stop bleeding.
Therefore, people with bleeding disorders (haemophiliacs, or those suffering a hemorrhagic diathesis) should not take Nattokinase supplements. Nor should people with ongoing bleeding problems, such as recent surgery, ulcers, haemorrhoids, or trauma. Likewise, people who have suffered major trauma in the previous month, ischemic stroke or neurosurgery in previous six months, or who have ever had an intracranial bleed should not use Nattokinase. And uncontrolled high blood pressure with a systolic blood pressure of 200 mmHg or a diastolic pressure of 110 mmHg also rules out Nattokinase supplementation.
Also, “blood thinning” drugs, such as aspirin or warfarin (Coumadin®), will put some people at greater risk of a bleeding problem if they also take Nattokinase. People taking these drugs should only use Nattokinase if their prescribing physician specifically advises them to do so, and is monitoring their progress carefully.
References
i. Sumi H, Hamada H, Nakanishi K, Hiratani H. “Enhancement of the fibrinolytic activity in plasma by oral administration of nattokinase.” Acta Haematol. 1990; 84(3): 139-43.
ii. Nishimura K, Hamamoto J, Adachi K, Yamazaki A, Takagi S, Tamai T. “Natto diet was apparently effective in a case of incipient central retinal vein occlusion.” Jpn Rev Clin Ophthalmol.1994; Sept 88(9):1381-5.
iii. Sumi H, Hamada H, Tsushima H, Mihara H, Muraki H. “A novel fibrinolytic enzyme (nattokinase) in the vegetable cheese Natto; a typical and popular soybean food in the Japanese diet.” Experientia. 1987 Oct 15; 43(10): 1110-1.
iv. Urano T, Ihara H, Umemura K, Suzuki Y, Oike M, Akita S, Tsukamoto Y, Suzuki I, Takada A. “The profibrinolytic enzyme subtilisin NAT purified from Bacillus subtilis cleaves and inactivates plasminogen activator inhibitor type 1.” J Biol Chem. 2001 Jul 6; 276(27): 24690-6.
v. Sumi H, Yatagai C, Kishimoto N. “A very strong activity of pro-urokinase activator in natto, the traditional fermented soybean in Japan.” Fibrinolysis. 1996; 10:31.
