Have you heard the buzz? There’s a supplement making waves, with headlines suggesting it can reduce blockages in your blood vessels by up to 95%. With heart disease still being the number one cause of death globally, a claim like that is bound to grab your attention. It certainly grabbed mine. The supplement in question is nattokinase, an enzyme derived from a traditional Japanese food. But with a new “miracle” supplement popping up every few months, you have to ask: is this one any different?
I know what you’re thinking because I was thinking it too. Is this the real deal, or just another bottle of hype? The interest in nattokinase exploded after a recent study involving over 1,000 people seemed to show incredible results. So, I decided to dive deep into the research—the good, the bad, and the downright misleading. We’re going to look at what the science actually says about nattokinase, whether pairing it with another supplement called serrapeptase helps, and most importantly, what you can actually do to virtually guarantee you never have a heart attack. The answers might surprise you. (Based on the insights of Dr. Brad Standfield)
Key Takeaways
- What is Nattokinase? Nattokinase is an enzyme extracted from natto, a traditional Japanese dish made from fermented soybeans. It’s believed to contribute to the longevity seen in Japanese populations.
- The Hype Study: A widely-cited 2022 study of over 1,000 people suggested nattokinase dramatically reduced cholesterol and artery plaque. However, this was a retrospective study, meaning it has significant design flaws and cannot prove cause and effect.
- The Gold-Standard Evidence: The best scientific evidence we have comes from a 3-year, randomized, placebo-controlled trial from 2021. This study found no difference in artery blockages between people taking nattokinase and those taking a placebo.
- Food vs. Supplement: While the evidence for nattokinase supplements is weak, the food natto is a fantastic, healthy choice, rich in protein, fiber, and vitamin K2.
- The Real Solution: Preventing heart disease isn’t found in a pill. It comes from proven lifestyle strategies like diet, exercise, and managing key health markers like blood pressure and cholesterol.
1. What is Nattokinase and Why is Everyone Talking About It?
Nattokinase is the active ingredient found in natto, a food made from fermented soybeans that has been a staple in Japan for centuries. If you’ve ever seen it, you know it has a very strong smell and a sticky, stringy texture—it’s definitely an acquired taste! For years, researchers have noted that populations with a high intake of natto seem to have a lower risk of heart disease, which is a major reason why it’s thought to contribute to the impressive longevity of the Japanese people.
The theory is that nattokinase works by breaking down fibrin, a protein involved in blood clotting. By doing so, it could potentially help dissolve existing blood clots and break down the atherosclerotic plaque that builds up and clogs our arteries, thereby preventing heart attacks and strokes. Early research seemed promising. Small studies showed it could decrease the clumping of red blood cells, prevent clots during long-haul flights, and reduce clotting factors in the blood. But the real excitement kicked into overdrive in 2022 with one particular study.
2. The “Miracle” Study: A Closer Look at the Hype
The paper that got everyone talking was titled, “Effective management of atherosclerosis progress and hypolipidemia with nattokinase.” It involved over 1,000 participants and reported a significant decrease in both cholesterol levels and the size of arterial plaque—by up to 36%—after just 12 months of taking nattokinase supplements.
On the surface, that sounds incredible. But here’s the massive problem: this was a retrospective study. This is a crucial point. A retrospective study is not the gold standard of scientific research. Instead of taking two similar groups and giving one the supplement and one a placebo, the researchers simply looked back at the medical records of people who had already decided to take nattokinase. They found people with high cholesterol or existing plaque who had newly started the supplement and tracked their results.
Why is this a problem? Because you have no idea what else these people were doing! Did they also start taking cholesterol-lowering medication? Did they change their diet or start exercising? Did they quit smoking? We don’t know. There was no comparison group. It’s impossible to say whether the improvements were because of the nattokinase or a dozen other lifestyle changes. Concluding that nattokinase was the cause is a huge leap that the study design simply doesn’t support.
3. The Gold Standard: What a Randomized Controlled Trial Revealed
Luckily for us, there is a much better study we can look at. In 2021, a double-blind, randomized controlled trial was published. This is the type of study you can trust. Researchers took 265 individuals and randomly assigned them to take either 2,000 FU (fibrinolytic units) of nattokinase or a matching placebo every day. Neither the participants nor the researchers knew who was taking what. This design eliminates bias and allows you to see the true effect of the supplement.
They followed these individuals for three years, using the exact same method as the other study (carotid ultrasound) to measure plaque in their arteries. And what were the results? After three years of treatment, there was no change in blood vessel blockages between the nattokinase group and the placebo group. None. It also had no effect on blood pressure or other blood markers.
This is the latest, largest, and longest-duration randomized trial on nattokinase, and it found no benefit. Now, critics might point out that the dose was lower than in the 2022 retrospective study (2,000 FU vs. 10,800 FU). While it would be interesting to see a high-dose RCT, as of right now, the best available evidence shows that nattokinase supplements do not reduce artery blockages.
4. What About Serrapeptase?
Often mentioned in the same breath as nattokinase, serrapeptase is another enzyme supplement that is thought to have anti-inflammatory and plaque-dissolving effects. However, when you look at the research, the story is even less compelling. The results from studies on serrapeptase have been negative and controversial, and there are reports of mild to moderate side effects that can’t be ignored. The bottom line is that much more research is needed, and it’s not a supplement I would recommend relying on for your heart health.
5. The 7 Proven Steps to Actually Prevent a Heart Attack
So, if you can’t rely on a supplement to protect your heart, what can you do? The good news is that you have an incredible amount of power to protect yourself from heart disease. Instead of looking for a magic pill, focus on these seven proven steps that can virtually guarantee you’ll never have a heart attack.
- Eat a Whole-Food Diet: This is your foundation. Focus on a diet high in lean protein and unsaturated fats from sources like avocado, extra virgin olive oil, nuts, and seeds. Load up on high-fiber foods like fruits and vegetables. And yes, natto (the food) can absolutely be part of this healthy diet! What you cut out is just as important: reduce or eliminate sugary foods, processed foods, fatty meats, butter, and excess salt.
- Move Your Body Regularly: You need a combination of both resistance exercise (like lifting weights) and cardiovascular exercise (like brisk walking, running, or cycling). Exercise strengthens your heart, improves circulation, and helps manage nearly every other risk factor on this list.
- Maintain a Healthy Weight: Your diet and exercise habits are the primary tools for maintaining a healthy weight. If you struggle in this area, don’t be afraid to seek help. Modern medications, like the GLP-1 class, can be powerful tools to assist you on your weight loss journey when used under a doctor’s supervision.
- Master Your Stress: We often underestimate the physical damage that chronic stress can do. It raises hormones that can harm your arteries over time. Making stress management a priority is non-negotiable. Practices like meditation and mindfulness are incredibly powerful and have real, measurable benefits for your cardiovascular system.
- Control Your Blood Sugar: If you’re following the diet and exercise advice, your blood sugar levels should be in a good place. However, some people still struggle. Persistently high blood sugar damages the lining of your arteries. If your levels remain high despite a healthy lifestyle, make sure to see your doctor.
- Keep Blood Pressure in Check: High blood pressure is often called the “silent killer” because it has no symptoms. The ideal target for your blood pressure, measured at home while you’re resting, should be below 120/80 mmHg. For people over 60, a slightly higher number (around 130) is often acceptable to avoid dizziness and falls.
- Optimize Your Cholesterol Levels: Finally, you need to manage your cholesterol. For many people, diet and exercise are enough. However, due to genetics, some people will still have high cholesterol despite doing everything right. In these cases, cholesterol-lowering medications like statins can be life-saving. Personally, I target an LDL (“bad”) cholesterol level below 60 mg/dL, and in addition to my lifestyle, I take a low dose of a statin to reach that goal.
Conclusion: Your Health is in Your Hands
The idea of a simple pill that can undo years of damage and protect us from heart disease is incredibly appealing. But when it comes to nattokinase, the scientific evidence just isn’t there to support the hype. The most reliable, gold-standard research shows no benefit.
Instead of chasing unproven supplements, the real path to a long and healthy life is one you control. The power to protect your heart lies in the daily choices you make—the food you eat, the way you move your body, and how you manage your health markers. It may not be as easy as swallowing a capsule, but it’s a proven strategy that puts your health and your future firmly back in your hands.
