Natto—a traditional Japanese dish made from fermented soybeans—is known for its distinct texture, smell, and potential health benefits. The dish is a staple of Japanese cuisine. Natto contains high levels of protein, the enzyme nattokinase, vitamin C, manganese, and vitamin k2. The fermentation process also offers probiotics, which can help to support digestive health. Some people who are working to improve their cardiovascular and/or neurological health have heard about the potential benefits of including nattokinase and vitamin k2 in their diet by incorporating natto into their nutrition plans.
Here, we'll learn more about natto, the potential benefits of including nattokinase and vitamin k2 in a heart-healthy diet, the connection between natto and brain health, and why it's important to talk with your doctor before changing your diet.
What is natto?
Salty, earthy, and slightly bitter, some people can't get enough natto—while others are put-off by the intense smell. The distinctive Japanese dish is created by soaking soybeans, steaming them, and then fermenting them with a bacterium called Bacillus subtilis var. natto.
In Japan, many people eat natto over rice for breakfast, and it's often used as a topping for sushi or noodles at other times in the day. While you can make natto on your own, you can also find the dish in the Asian foods sections of many grocery stores, as well as in health food stores. If you struggle with the taste or consistency of natto, many fans of the dish recommend mixing it with rice, quinoa, or other grains. Topping natto with mustard or soy sauce can help to offset the strong taste and smell, making it more palatable as you get used to the unique aromas and flavors of the dish.
What is nattokinase?
Nattokinase is an enzyme derived from the bacteria used to ferment natto. We talked to Dr. Matthew Segar, a cardiologist at Texas Heart Institute, about the benefits of including natto in a heart-healthy diet. "One of its effects is to help dissolve clots," he said. Dr. Segar said that the enzyme is a fibrinolytic, meaning it breaks down fibrin—a protein involved in blood clotting.
When fibrin is broken down in the blood, it can help to keep the blood thin, which may help protect against conditions related to blood clots, including heart attack and stroke. Some people take nattokinase for high blood pressure and high cholesterol, but research has yet to prove that the enzyme is helpful for either of these conditions.
What is vitamin k2?
This fat-soluble vitamin works to help the body regulate calcium, making it vital for maintaining both strong bones and cardiovascular health. Also known as menaquinone, vitamin k2 helps calcium go where it's needed in the body—to the bones and teeth—and away from areas where calcification can do harm, such as in the arteries. People who don't get enough vitamin k2 may be at higher risk for osteoporosis and cardiovascular issues. In addition to fermented foods like natto, vitamin k2 can also be found in many animal products, including egg yolks, butter, and dark meat chicken.
Where can you find nattokinase and vitamin k2 together?
Natto is the best way to get vitamin k2 and nattokinase together from whole food sources. If eating natto isn't an option, it's a good idea to explore supplementation. There are many supplements available that combine nattokinase and vitamin k2 into a single softgel.
How nattokinase and vitamin k2 can support heart health
Dr. Segar said that nattokinase and vitamin k2 can work together to protect cardiovascular health. "Nattokinase may improve blood flow and clot prevention, while k2 may reduce arterial stiffness and calcification," he said. While nattokinase works to thin out the blood and lessen the likelihood of clotting issues, vitamin k2 works to create clear pathways, allowing blood to flow freely throughout the body. Together, both components work to support a healthy cardiovascular system.
Alzheimer's, nattokinase, and vitamin k2
In addition to supporting cardiovascular health, there is some evidence that nattokinase and vitamin k2 may help to protect the brain against conditions like Alzheimer's disease. According to Dr. Segar, "There are some studies which suggest nattokinase might help with reducing amyloid plaques in the brain, which are commonly seen in Alzheimer's disease."
Recent studies have shown that vitamin k2 can also support neurological health. A 2025 study found a potential link between vitamin k2's ability to mitigate arterial calcification and its ability to stunt cognitive impairment in older adults. Research also shows that vitamin k2 may play a role in regulating circadian rhythms, potentially making it easier for you to get the healthy sleep necessary to support neurological health.
Why talking to your doctor before using nattokinase and vitamin k2 matters
Dr. Segar recommends talking to your doctor if you're considering taking nattokinase and/or vitamin k2 supplements, or if you're planning on adding natto to your diet.
"The most important thing if you're considering taking these supplements is to first discuss it with your physician," Dr. Segar said. "The supplement may interact with medications, especially anticoagulants, or may be contraindicated in certain medical conditions."
We're here to support every step of your health journey.
Whether you're researching "nattokinase blood pressure," are just starting to prioritize heart health, or you've been on a health journey for years, Evidation is here to provide you with the insights and information you need to keep moving forward. When you download our free app, you'll be prompted to share the health data you're already tracking (your privacy is extremely important to us, and you can choose to stop sharing your data with us at any time). We'll take the information you choose to share with us to find patterns and insights that we'll use to offer you personalized, content-based suggestions that you can use to continue taking your health to the next level. Click here to learn more about how Evidation works and download the app today.
