Nattokinase

## Introduction to Nattokinase For over a thousand years, the Japanese have consumed a traditional dish called natto—a sticky, strong-smelling food made from fermented soybeans. Long associated with the remarkable cardiovascular health and longevity of the Japanese population, the exact mechanism behind natto's benefits remained a mystery until 1980. It was then that Dr. Hiroyuki Sumi, a researcher at the Chicago University Medical School, dropped a small amount of natto extract onto an artificial blood clot in a petri dish. To his astonishment, the clot completely dissolved within 18 hours. Dr. Sumi had discovered nattokinase, a potent, naturally occurring enzyme that has since become one of the most highly regarded natural supplements for cardiovascular health.

Nattokinase is a serine protease enzyme produced by the probiotic bacterium *Bacillus subtilis* during the fermentation process of soybeans. Despite its name, it is not a 'kinase' but a protease—an enzyme that breaks down proteins. Specifically, nattokinase is exceptionally skilled at breaking down fibrin, the tough protein mesh that forms the structural foundation of blood clots. Today, nattokinase is extracted, purified, and encapsulated, allowing people worldwide to reap the cardiovascular benefits of natto without having to acquire a taste for the pungent, gooey fermented dish.

## How Nattokinase Works: The Biochemistry of Blood Flow The human body maintains a delicate balance between coagulation (forming clots to stop bleeding) and fibrinolysis (dissolving clots to maintain blood flow). As we age, or due to poor diet, stress, and sedentary lifestyles, this balance often tips toward coagulation. Blood becomes thicker, more viscous, and prone to forming dangerous clots that can lead to heart attacks, strokes, or deep vein thrombosis (DVT).

Nattokinase intervenes in this process through a multi-targeted approach:

**1. Direct Fibrinolysis:** Nattokinase directly attacks and cleaves cross-linked fibrin. It acts as a biological pair of scissors, cutting the protein threads that hold blood clots together. Research indicates that nattokinase is up to four times more potent at dissolving clots than plasmin, the body's own natural clot-busting enzyme.

**2. Boosting the Body's Natural Defenses:** Nattokinase doesn't just work alone; it recruits the body's internal systems. It degrades a molecule called Plasminogen Activator Inhibitor-1 (PAI-1). By removing PAI-1, nattokinase frees up tissue plasminogen activator (t-PA), which in turn produces more plasmin, exponentially increasing the body's ability to clear out arterial blockages.

**3. Lowering Blood Pressure via ACE Inhibition:** High blood pressure forces the heart to work harder and damages the delicate inner lining of blood vessels (the endothelium). Nattokinase has been shown to inhibit Angiotensin-Converting Enzyme (ACE). By blocking ACE, nattokinase prevents blood vessels from constricting, allowing them to relax and dilate, which naturally lowers both systolic and diastolic blood pressure.

## Cardiovascular Benefits and Clinical Evidence The clinical data supporting nattokinase is robust, earning it a solid reputation in both integrative medicine and clinical sports nutrition.

**Reducing Clotting Factors:** A landmark 2009 study published in *Nutrition Research* by Hsia et al. examined 45 subjects, including healthy volunteers and those with cardiovascular risk factors. After taking 4,000 FU of nattokinase daily for two months, all groups saw significant decreases in key clotting markers, including fibrinogen, Factor VII, and Factor VIII. This proved that nattokinase doesn't just dissolve existing clots; it proactively prevents the blood from becoming overly coagulable in the first place.

**Managing Hypertension:** A 2008 randomized, double-blind, placebo-controlled trial by Kim et al. focused on 86 individuals with pre-hypertension or stage 1 hypertension. Subjects taking 2,000 FU of nattokinase daily for eight weeks experienced a statistically significant drop in both systolic and diastolic blood pressure compared to the placebo group.

**Deep Vein Thrombosis (DVT) Prevention:** Long periods of immobility, such as during long-haul flights, drastically increase the risk of DVT. Studies have shown that a combination of nattokinase and other supportive compounds taken before a flight can virtually eliminate the formation of micro-clots in the legs, making it a must-have supplement for frequent travelers.

## Understanding Dosing: The Importance of Fibrinolytic Units (FU) When shopping for a nattokinase supplement, label literacy is critical. Unlike most vitamins or minerals that are measured purely by weight (milligrams), enzymes must be measured by their *activity level*. For nattokinase, this measurement is the Fibrinolytic Unit (FU).

The clinical standard dose for cardiovascular maintenance is **2,000 FU per day**, which typically equates to about 100mg of high-quality nattokinase extract.

If you look at a supplement facts panel and it only says "Nattokinase ... 100mg" without listing the FU, consider it a red flag. The weight of the powder does not guarantee that the enzyme is active or potent. Always look for products explicitly standardized to provide at least 2,000 FU per serving.

In clinical settings, doses up to 10,800 FU (approx. 540mg) have been used safely for up to a year, but for general health, circulation support, and blood pressure management, 2,000 to 4,000 FU daily is the sweet spot.

## Safety, Side Effects, and Contraindications Nattokinase is generally recognized as safe, especially considering its origins as a traditional food consumed daily by millions of people for centuries. Clinical trials testing doses up to 552mg per day for four weeks, and 540mg per day for a year, reported no adverse side effects.

However, because nattokinase is a highly effective blood thinner, it demands respect and careful use in specific populations:

* **Prescription Blood Thinners:** If you are taking Warfarin (Coumadin), Clopidogrel (Plavix), Aspirin, or other anticoagulants, you must consult your doctor before taking nattokinase. The synergistic effect can lead to a dangerously high risk of bleeding or bruising. * **Upcoming Surgery:** Because it prevents blood from clotting, nattokinase can cause excessive bleeding during surgical procedures. It must be discontinued at least two weeks prior to any scheduled surgery or dental work. * **Bleeding Disorders:** Individuals with hemophilia, von Willebrand disease, or a history of hemorrhagic stroke should strictly avoid nattokinase. * **Blood Pressure Medications:** Since nattokinase naturally lowers blood pressure, combining it with prescription antihypertensives can cause blood pressure to drop too low (hypotension).

## Nattokinase vs. Vitamin K2: The Natto Paradox A common point of confusion arises regarding nattokinase and Vitamin K2. Whole natto food is incredibly rich in both nattokinase and Vitamin K2. However, Vitamin K plays a crucial role in *promoting* blood clotting—the exact opposite of what nattokinase does.

To resolve this, high-quality nattokinase supplements undergo a purification process to remove the Vitamin K2. This ensures that the supplement delivers pure, unhindered fibrinolytic (blood-thinning) activity without the counteractive clotting effects of Vitamin K. If you are taking nattokinase specifically to thin the blood and reduce clots, ensure your supplement specifies that Vitamin K has been removed.

## Conclusion Nattokinase stands as a prime example of ancient dietary wisdom validated by modern clinical science. By directly degrading fibrin, lowering blood pressure, and improving overall blood rheology, it offers a powerful, natural intervention for those looking to protect their cardiovascular system. Whether you are an athlete looking to improve microcirculation and nutrient delivery, a frequent traveler guarding against DVT, or someone proactively managing their heart health, nattokinase is a scientifically backed, highly effective enzyme to add to your regimen.