Most statin users were never told that this natural enzyme cleared plaque three times better in a clinical trial — and doctors say it is reshaping what may be possible for clogged arteries

What if the world’s leading killer had an unexpected challenger — not from a cutting-edge laboratory, but from a traditional Japanese food? It may sound hard to believe, yet growing research is pointing to an enzyme called nattokinase as a potentially powerful tool against cardiovascular disease. For years, clogged arteries were seen as something you could slow down, but not truly reverse. New findings are beginning to challenge that assumption.

Atherosclerosis, the process behind hardened and narrowed arteries, develops quietly over time. It is a bit like rust accumulating inside a pipe until flow is restricted and pressure rises. In the body, that can end in a heart attack or stroke. Statins have played an important role in slowing the process, but they have not been known to fully clear existing plaque. In this article, we look at the science behind nattokinase, the studies drawing attention, and what it could mean for heart health.

Key Takeaways

Atherosclerosis is the buildup of fatty plaque in the arteries and can lead to heart attacks and strokes.
Standard treatments such as statins can slow plaque growth by lowering cholesterol, but they are not designed to remove plaque already present.
Nattokinase is a natural enzyme derived from natto, a fermented soybean food from Japan, and is known for breaking down blood clots.
Human studies suggest nattokinase may substantially reduce arterial plaque, with one study reporting a reduction of more than 36% over six months.
Dosage appears to matter: higher doses have shown benefits, while lower doses have not produced the same results.
Because nattokinase can thin the blood, it should only be considered after discussing it with a healthcare provider, especially if other medications are being taken.

1. What Is Atherosclerosis, and Why Is It So Dangerous?

To understand the potential solution, it helps to understand the problem. Arteries are the body’s transport network, carrying oxygen-rich blood from the heart to the rest of the body. When they are healthy, blood moves through them easily. Atherosclerosis begins when plaque starts building along the artery walls and creates blockages.

Plaque is not made of just one thing. It is a mixture of LDL cholesterol, fats, cellular waste, calcium, and fibrin, a clotting substance. The process often starts after the artery’s inner lining, known as the endothelium, is damaged by factors such as high blood pressure, smoking, or elevated blood sugar. Immune cells called macrophages rush in to clear cholesterol from the damaged area. If they become overloaded, they turn into so-called foam cells, become trapped in the artery wall, and eventually die, releasing material that fuels more inflammation. Over time, this cycle enlarges and hardens the plaque, narrowing the artery.

The greatest danger comes when a plaque ruptures. The body responds by forming a clot to repair the damage, but that clot can block the already narrowed artery. If the blockage happens in a vessel that supplies the heart, it causes a heart attack. If it occurs in the brain, it causes a stroke.

2. The Limits of Conventional Treatment

For decades, the main approach to atherosclerosis has been lowering LDL cholesterol, most often with statins. These drugs have saved many lives by reducing the amount of cholesterol the liver makes, which lowers the amount circulating in the blood. That in turn helps slow the formation of new plaque and can reduce the pace of existing plaque growth.

Still, statins are mainly a containment strategy. They are effective at slowing disease progression, but they do little to remove plaque that is already there. Even in major trials, the best outcomes for intensive cholesterol-lowering therapy have generally shown plaque regression of only about 10% to 15% in some patients. That is helpful, but it falls short of a true cure. The search has continued for something that can actively break down existing plaque.

3. Nattokinase: An Enzyme From Fermented Soybeans

That search leads to natto, a food that has been part of Japanese cuisine for centuries. Natto is made by fermenting soybeans with the bacterium Bacillus subtilis natto. It is famous for its strong smell and sticky, stringy texture, which many people outside Japan need time to appreciate. Hidden inside this traditional food is the enzyme nattokinase.

Nattokinase was identified in the 1980s by Dr. Hiroyuki Sumi, who was looking for a natural clot-dissolving substance. He found that a small amount of natto placed on an artificial blood clot in a petri dish caused the clot to dissolve within hours. The enzyme responsible was named nattokinase. It has strong fibrinolytic activity, meaning it can break down fibrin, the structural mesh that holds a clot together. That is why it has been studied for its potential role in supporting circulation and limiting dangerous clot formation.

4. The Study That Drew Attention

Although nattokinase was already known for its clot-busting properties, a clinical trial published in the Chinese Journal of Medicine brought it attention for another reason: plaque reduction. The 26-week study involved 76 patients with atherosclerotic plaque in the carotid arteries, the major neck vessels that carry blood to the brain.

Participants were divided into two groups. One group took 20 mg of simvastatin daily, while the other took 6,000 FU of nattokinase per day. The results were striking. Both groups showed some reduction in plaque, but the difference was substantial. The statin group saw an 11.5% decline in plaque size, while the nattokinase group averaged a 36.6% reduction.

That was more than three times the effect seen with the statin. The nattokinase group also showed better blood lipid results, including lower triglycerides and LDL cholesterol and higher HDL cholesterol. For a natural supplement to produce that kind of effect was unusual and prompted further interest.

5. Does the Dose Matter?

As with many supplements, the amount used may be critical. The most encouraging results came from studies using a relatively high dose of 6,000 FU per day. Lower-dose studies have not shown the same outcome. For example, a trial led by Dr. Howard Hodis used 2,000 FU per day and reported a null effect on atherosclerosis progression.

By contrast, a larger study published in Frontiers in Cardiovascular Medicine reported results that again supported a dose-dependent response. That year-long study involved more than 1,000 patients and used 10,800 FU per day. Participants saw their total plaque area fall by an average of 36.9%. LDL cholesterol dropped by more than 18%, while HDL cholesterol rose by nearly 15%. The pattern suggests that nattokinase may only be effective at sufficiently high doses, and some supplements may not provide enough activity to match the studies.

6. How Might Nattokinase Work?

Researchers are still working to understand exactly how nattokinase reduces plaque, but several explanations are being explored. Its fibrinolytic action is likely central. Because atherosclerotic plaque contains a fibrous cap rich in fibrin, nattokinase may help break down that framework and allow the body to clear the material more easily.

The enzyme also appears to influence risk factors beyond the plaque itself. Studies have shown improvements in lipid profiles, including lower LDL and triglycerides and higher HDL. In addition, it has been associated with anti-inflammatory and blood-pressure-lowering effects. Together, those actions may help create conditions that are less favorable for plaque development and more favorable for repair.

7. Important Cautions

These findings may make nattokinase sound appealing, but caution is essential. The enzyme has meaningful blood-thinning effects, which are part of how it works. For that reason, it should never be combined with prescription blood thinners such as warfarin, Eliquis, Xarelto, or even daily aspirin without direct medical supervision. Doing so could raise the risk of serious bleeding.

It is also important to remember that the research is still relatively new, and more work is needed to confirm long-term safety and effectiveness. Supplement quality can vary widely, so a product with clearly stated FU activity from a reputable source is important. As with any change to a health routine, the best step is to speak with a trusted healthcare professional who understands your medical history and can advise whether nattokinase is appropriate.

Conclusion

The research on nattokinase and plaque reduction is one of the more intriguing developments in cardiovascular health in recent years. It challenges the long-standing idea that clogged arteries can only be slowed, not improved. Statins remain an important part of heart disease prevention, but nattokinase may offer a complementary approach that helps address plaque already present.

It is not a miracle cure, and it does not replace healthy eating or regular exercise. Still, it is a striking example of how natural compounds can sometimes deliver effects that rival conventional drugs. As studies continue, more will become clear, but for now nattokinase stands out as a hopeful possibility in the fight against cardiovascular disease.

Sources

Chen, H., Chen, J., Zhang, F., Li, Y., Wang, R., Zheng, Q., Zhang, X., Zeng, J., Xu, F., & Lin, Y. (2022). Nattokinase improves blood lipids and atherosclerotic plaque in patients with hyperlipidemia. Frontiers in Cardiovascular Medicine, 9, 964977. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9441630/
Ren, Y., Zuo, H., Ma, F., Li, S., & Liu, J. (2017). [A clinical study on the effect of nattokinase on carotid artery atherosclerosis and hyperlipidaemia]. Zhonghua yi xue za zhi, 97(26), 2038–2042. (Abstract in English)
Weng, Y., Yao, J., Wang, S., & Zhang, Y. (2017). Nattokinase: A Promising Alternative in Prevention and Treatment of Cardiovascular Diseases. Biomarker Insights, 12, 1177271917725024. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5569271/
Hodis, H. N., Mack, W. J., & Kono, N. (2023). Nattokinase for prevention of subclinical atherosclerosis and cognitive decline: a randomized controlled trial. Scientific Reports, 13(1), 19089. https://www.nature.com/articles/s41598-023-46286-5