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Natto is a traditional Japanese food made from fermented soybeans. Nattokinase, the enzyme produced in natto during fermentation, has powerful anti-clotting effects that act as a preventative for arterial plaque buildup and, as a result, bad heart outcomes.
Natto is also rich in protein, fiber, probiotics, and vitamin K2, all of which offer health benefits like improved digestion, bone strength, and a stronger immune system. It’s a true superfood.
1. Promotes Cardiovascular Health
Natto’s heart health effects are thanks to the enzyme nattokinase. Research shows that nattokinase helps dissolve fibrin, a protein involved in blood clot formation. (1) This anti-clotting activity supports blood flow and reduces the risk of thrombosis and arterial plaque buildup.
Studies show natto may also have a positive effect on balancing blood pressure and cholesterol levels. (2) While cholesterol shouldn’t be the sole marker you look at for optimal heart health, low levels of LDL cholesterol are linked to a reduced risk of heart disease.
Apart from nattokinase, the plant-based protein is full of additional vitamins and minerals known to support overall wellness, including a healthy heart. Natto is rich in vitamin K2, for example, which is known to improve arterial flexibility. (3)
A single serving of natto gets you close to the daily recommended intake of manganese, too. Manganese is known for supporting enzyme functions that handle blood clotting and metabolism. (4) All of this combined makes natto a great addition to a heart-healthy diet.
2. Benefits Gut Health
Fermented foods are generally full of natural probiotics, and nutritious natto is no exception. Natto contains Bacillus subtilis (B.subtilis), a probiotic that balances gut microbiota, strengthens the intestinal barrier, and reduces inflammation in the gut. (5)
Natto is also a high-fiber food. Fiber alleviates gut issues like constipation, helps balance cholesterol levels, and may even help you feel fuller for longer.
Since everything in the body is connected, a healthy gut impacts overall wellness. Studies show that a balanced microbiome is good for your metabolism and immune system and reduces your risk of chronic conditions like type 2 diabetes. (6) It’s even good for your mental health. (7)
3. Strengthens Bones
Natto’s fermentation process results in a food rich in the form of vitamin K2, known as menaquinone-7. It plays an important role in activating protein hormones like osteocalcin that bind calcium to your bones. (8) This means stronger bones and a reduced risk of osteoporosis.
Natto also contains calcium and magnesium, essential minerals for bone health, bone mineral density, and even postmenopausal women at a higher risk of bone loss. Magnesium helps your body convert vitamin D into its active form for better calcium absorption.
The health benefits of natto also come from its isoflavones. These are phytoestrogens, or plant compounds that mimic estrogen in the body, that support hormonal balance, which is vital to bone loss in women as they age. (9)
It’s important to note here that phytoestrogens like genistein and daidzein in natto aren’t estrogen. They’re not as potent. They can influence hormone balance, though, by binding to estrogen receptors in the body. (10)
If you’re worried about hormonal effects of soy-based products like natto due to a pre-existing condition, talk to your doctor or dietitian about the right dietary options for you.
4. Rich in Nutrients
The nutritional profile of natto can help you meet your Daily Value (DV) of many vitamins and minerals. We’ve mentioned a few already, but let’s dig into the rest.
Serving sizes will vary depending on your goals, but you can expect the following from 100g, or a little over half a cup, of natto:
Calcium: 217mg (17% DV)
Carbohydrates: 14g (5% DV)
Fiber: 9.5g (34% DV)
Iron: 8.6mg (48% DV)
Magnesium: 115mg (27% DV)
Manganese: 1.5mg (65% DV for me, 83% DV for women)
Phosphorus: 174mg (14% DV)
Potassium: 729mg (16% DV)
Protein: 19g (49% DV)
Selenium: 17.9mcg (33% DV)
Vitamin B6: 0.13mg (8% DV)
Vitamin C: 13mg (14% DV)
Vitamin K2 (Menaquinone-7): ~900 mcg (750% DV for men, 1000% DV for women)
Zinc: 3mg (28%)
5. Helps Manage Blood Pressure
Natto supports balanced blood pressure through nattokinase, the enzyme we told you about that breaks down fibrin. This process improves blood flow, relaxes your blood vessels, and reduces your risk of hypertension. (2)
Vitamins and minerals in natto, like potassium and vitamin K2, also play a role in supporting vascular health. Potassium levels out your sodium levels for better circulation. Vitamin K2 improves vascular flexibility, reducing strain on your heart. (11)
6. Reduces Inflammation
Antioxidants in natto may reduce existing inflammation in a few different ways. The same probiotics responsible for balancing your microbiome produce short-chain fatty acids that reduce inflammatory markers in the gut. (12)
Better blood flow and the ability of nattokinase to dissolve blood clots can indirectly reduce inflammation from poor circulation and impacted blood vessels. (13) Natto’s nutritional profile can also reduce oxidative stress.
That’s good news for chronic disease risk and for how you feel. Chronic oxidative stress can cause fatigue, brain fog, weakened immunity, and slow down recovery from exercise or injuries. Over time, it can even accelerate the signs of aging.
7. Can Improve Immune System Function
Any attempt at reducing overall inflammation in the body is great for your immune system. Natto’s probiotics support immune defense by regulating immune cells that start in the gut. Nutrients in natto, like vitamin C, iron, and zinc, are known immune boosters.
The unique peptides in natto may also have an antimicrobial effect. One study found that natto extract targets the bacteria Streptococcus pneumoniae, which is responsible for ear infections, sinusitis, pneumonia, and meningitis. (14)
We already know natural approaches like nattokinase could reduce our reliance on medications like statins. Researchers are now looking into whether antimicrobials and soy foods like natto could be an answer in the future to antibiotic-resistant strains of bacteria.
8. Supports Weight Management
Natto won’t help you lose weight in isolation, but it can be a positive addition to a diet that prioritizes a healthy weight. Fermented foods support a healthy gut microbiome, which positively affects your metabolism and how your body stores fat. (15)
Natto’s high fiber content supports digestion and promotes satiety, which can help you feel full longer. Its high protein content helps preserve muscle mass while promoting fat loss.
Regular consumers also report that natto gives them an energy boost. This may be thanks to its effects on digestion and nutrient absorption, allowing your body to convert food into energy more efficiently. (16) That may also be why it’s a breakfast staple among Japanese foods.
Serving sizes are essential. Natto is relatively calorie-dense with about 212 calories per 100g, so portion control is important if you monitor calories. Many packaged versions consist of a little over half that amount per serving. A little can go a long way with your natto consumption.
Forms of Natto
Natto is available in several forms. Asian supermarkets may sell it fresh in small, individually wrapped packets. Freeze-dried natto has a longer shelf life and is popular for use in miso soups. Some packaged versions come with condiments like mustard or soy sauce.
If you’d like to prepare it at home, you’ll need soybeans and a natto starter culture containing B. subtilis or rice straw, a natural source of the bacteria. Natto fermentation takes about 24 hours plus soaking time for your beans.
Natto powder is made by grinding dried natto into a fine powder for smoothies or shakes. Supplements typically come in capsule form to make consumption easier for the first-time user. They’re also great for those who don’t love the taste of natto.
Flow | Nattokinase (10,800 FU)
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Find Your Flow A daily powdered supplement designed to promote clear, efficient blood flow and circulation, ensuring vital nutrients reach your heart and organs while supporting your body’s ability to clear metabolic waste for sustained vitality and overall wellness.… read more
Toku Flow is a daily supplement with 10,800 FU of nattokinase for effective, efficient delivery of all the health benefits of natto. It contains vitamin K2 and beta-glucan for optimized blood pressure, balanced cholesterol, and bone health support without the side effects of pharmaceuticals.How Often You Should Have It
In Japan, it’s common to eat natto at breakfast with green onion on rice or toast. It’s safe to eat daily, but consumption varies by person. While it’s an incredibly healthy food, diversity in your diet is also important.
A supplement can help you be consistent and get health boosts with less effort, especially if you think natto is an acquired taste. Natto has a unique flavor profile big on umami that isn’t for everyone.
Nattokinase supplements are safe to take daily. Most come in capsules of 2,000 fibrinolytic units (FU) to be taken once or twice per day. Those with existing health conditions may benefit from a higher dose. One study saw big improvements in atherosclerosis risk at 10,800 FU per day. (17)
Risks
Natto has been a staple of the Japanese diet for thousands of years and is generally regarded as safe for regular consumption by most people.
However, as a fermented food with active enzymes, probiotics, and high vitamin K2 content, it can potentially cause side effects or interact with medications. Those possible side effects include:
Allergic reactions, particularly in those sensitive to soy
Stomach discomfort, bloating, or nausea
Dizziness or lightheadedness due to blood-pressure-lowering properties
Increased bleeding or bruising risk
Talk to your healthcare provider before consuming natto or taking a nattokinase supplement, especially if you’re on anticoagulants, blood thinners, or antihypertensives. Avoid consuming it in the weeks leading up to scheduled surgeries due to the risk of increased bleeding.
Pregnant or breastfeeding individuals should talk to their doctor before any changes to their diet, as that’s a group that isn’t regularly studied in clinical trials evaluating supplements.
The Bottom Line
Deaths from cardiovascular disease in the United States outnumber those in Japan 2:1. Diet is an essential factor in those stats. It’s no secret that fermented foods are a staple in Japanese diet and largely absent from most American diets.
Natto can be a powerful addition to your diet for better heart health, but it also has benefits beyond cardiovascular support. It’s good for your bones, your immune system, and your gut. It can help you live better longer.
If consuming natto regularly isn’t in the cards for you, nattokinase supplements are just as good. They may even help you reduce your reliance on medications commonly prescribed at the first signs of heart disease.
Sources
- Nattokinase: A Promising Alternative in Prevention and Treatment of Cardiovascular Diseases
Effects of nattokinase on blood pressure: a randomized, controlled trial
Vitamin K2-a neglected player in cardiovascular health: a narrative review
Nattokinase attenuates endothelial inflammation through the activation of SRF and THBS1
