What Exactly is Natto?
Natto is a traditional Japanese food made from whole soybeans that have been soaked, steamed, and then fermented with the bacterium Bacillus subtilis var. natto. This fermentation process is responsible for the product's distinctive sticky, stringy texture and strong, pungent aroma. While its unique characteristics can be polarizing, its nutritional profile is undeniably impressive, making it a superfood in many health circles. Historically, natto has been a staple in Japanese cuisine for centuries, often served over rice with soy sauce and Japanese mustard, and is now gaining recognition worldwide for its therapeutic potential.
Digestion and Gut Health
One of the most significant advantages of natto is its positive impact on digestive health. The fermentation process transforms the soybeans, creating a rich source of probiotics and prebiotics.
- Probiotics: Natto contains a high concentration of live bacteria, specifically Bacillus subtilis. These microorganisms can colonize the gut, promoting a balanced and healthy gut microbiome. A diverse microbiota is crucial for various bodily functions, including nutrient absorption and immune defense.
- Prebiotics: The dietary fiber in natto acts as a prebiotic, nourishing the beneficial bacteria already present in the gut. This symbiotic relationship helps improve overall digestive function, alleviating common issues like constipation and bloating.
Cardiovascular Health
Natto contains a powerful enzyme called nattokinase, a key compound for cardiovascular wellness. The benefits of natto fermented beans for heart health have been studied extensively.
- Nattokinase: This enzyme helps break down fibrin, a protein involved in blood clotting. By dissolving existing blood clots and reducing the blood's viscosity, nattokinase can improve circulation and lower the risk of conditions like heart attacks and strokes.
- Blood Pressure Regulation: Research suggests that regular consumption of natto can contribute to lowering blood pressure. This effect is attributed to nattokinase and other bioactive compounds that help relax blood vessels and improve blood flow.
- Cholesterol Reduction: Studies have also found that the polyunsaturated fats and fiber in natto can help decrease 'bad' LDL cholesterol levels, further supporting overall heart health.
Bone Strengthening
Natto is an exceptional plant-based source of vitamin K2, a crucial nutrient for bone health that is often scarce in modern diets. Vitamin K2 plays a vital role in regulating calcium metabolism by activating specific proteins.
- Calcium Integration: It ensures that calcium is properly directed to the bones and teeth, where it is needed for strength, rather than accumulating in soft tissues like arteries.
- Osteoporosis Protection: Multiple studies have shown a link between high vitamin K2 intake, such as that from natto, and improved bone mineral density, especially in postmenopausal women. This helps protect against osteoporosis and reduces the risk of fractures.
Other Health Advantages
Beyond its core benefits for digestion, heart, and bones, natto offers several other health advantages due to its rich nutritional profile and unique bioactive components.
- Rich in Nutrients: Natto is packed with essential vitamins and minerals, including iron, magnesium, manganese, potassium, and zinc. It also provides a significant amount of plant-based protein, with all nine essential amino acids.
- Anti-Inflammatory and Antioxidant Properties: Bioactive compounds in natto have been shown to possess anti-inflammatory and antioxidant effects. These properties help combat oxidative stress and chronic inflammation, which are underlying causes of many diseases.
- Enhanced Nutrient Absorption: The fermentation process not only creates new beneficial compounds but also breaks down anti-nutrients like phytates and lectins, which are naturally found in soybeans. This makes the nutrients in natto easier for the body to absorb.
- Immune System Support: A healthy gut microbiome, supported by natto's probiotics, is intrinsically linked to a robust immune system. Furthermore, its rich vitamin and mineral content provide the body with the necessary tools to fight off pathogens.
Natto vs. Other Fermented Soy Products
While several fermented soy products exist, natto's unique fermentation process and bacterial culture give it a distinct nutritional edge, particularly concerning vitamin K2 and nattokinase. Here is a comparison of natto to two other popular fermented soy foods:
| Feature | Natto | Miso | Tempeh |
|---|---|---|---|
| Key Bacteria | Bacillus subtilis var. natto | Mold (Aspergillus oryzae), yeast, and other bacteria | Mold (Rhizopus oligosporus) |
| Probiotic Count | Very high, with live bacteria | Present, but often killed during cooking | Contains live bacteria but less concentrated than natto |
| Vitamin K2 | Exceptionally high concentration | Lower compared to natto | Present, but lower than natto |
| Nattokinase | Unique to natto | Absent | Absent |
| Texture | Sticky and slimy | Smooth paste | Firm, cake-like texture |
| Common Use | Breakfast food with rice, soup topping | Flavoring for soups, sauces | Meat substitute, grilled or fried |
Conclusion: Making the Most of Natto's Benefits
The benefits of natto fermented beans are vast and supported by a growing body of research. From enhancing gut and heart health to fortifying bones, this traditional Japanese superfood is a powerhouse of nutrients. Its unique compounds, such as nattokinase and vitamin K2, make it stand out among other fermented soy products. Although its flavor and texture may require some getting used to, the health rewards are well worth it. Integrating natto into your diet can be a proactive step toward better long-term wellness.
Creative Ways to Eat Natto
For those new to natto, its strong flavor and slimy texture can be a hurdle. However, it can be enjoyed in many ways that balance its unique qualities.
- With rice: The traditional method is to serve it over a bed of warm rice with soy sauce and mustard. The heat from the rice can help mellow the flavor.
- In soups: Stirring natto into miso soup can add nutrition and depth of flavor.
- With other flavors: Combining natto with strong condiments like kimchi or curry powder can mask the potent aroma.
- In salads or wraps: Mixing natto with other ingredients in a salad or tortilla wrap can make it more approachable.
- Blended into smoothies: For those who cannot tolerate the texture, blending it into a smoothie is an excellent way to get the nutrients without the stringiness.
Disclaimer: Individuals on blood-thinning medication should consult their doctor before adding significant amounts of natto to their diet due to its high vitamin K content, which can affect blood clotting.
