The Nutritional Powerhouse of Natto
Natto is a nutritional powerhouse, with a rich profile of vitamins, minerals, and bioactive compounds. It’s made by fermenting soybeans with the bacterium Bacillus subtilis var. natto, a process that not only creates its distinct sticky texture but also significantly enhances its nutritional value. A 100-gram serving of natto is packed with protein, fiber, and an impressive amount of vitamin K2.
Fermentation makes natto's nutrients more bioavailable, meaning the body can absorb and utilize them more efficiently. This process breaks down antinutrients naturally found in soybeans, reducing their impact and making the food easier to digest.
Daily Natto Benefits: What the Science Says
Heart Health Daily consumption of natto can be highly beneficial for cardiovascular health, primarily due to the enzyme nattokinase. This enzyme helps break down fibrin, a protein involved in blood clotting. Research suggests that nattokinase may help dissolve existing blood clots, reduce blood pressure, and improve blood flow, thereby lowering the risk of heart attacks and strokes. One long-term study involving 92,000 Japanese individuals found that those who consumed 1.8 ounces of natto daily had a 10% lower risk of cardiovascular disease and premature death.
Bone Strength Natto is one of the richest food sources of vitamin K2, which is crucial for bone health. Vitamin K2 activates proteins that help bind calcium to the bones, increasing mineral density and reducing the risk of fractures. This helps to prevent conditions like osteoporosis, a common concern as we age. Interestingly, research has also suggested that a regular intake of natto may help prevent age-related bone loss in postmenopausal women.
Gut Health and Digestion As a fermented food, natto is rich in beneficial probiotics and prebiotics. Probiotics, such as the Bacillus subtilis strain, help balance the gut microbiome, which is essential for healthy digestion and a strong immune system. The high fiber content further supports digestive health by promoting regular bowel movements and alleviating issues like constipation and bloating. A healthy gut microbiome is also linked to numerous other benefits, including reduced inflammation.
Immune System Support A significant portion of the body's immune system resides in the gut. By promoting a healthy and diverse gut flora, the probiotics in natto can strengthen immune function. In addition to probiotics, natto contains other immune-boosting nutrients like vitamin C, zinc, and iron. Some studies suggest that the Bacillus subtilis probiotic strain may help reduce the risk of respiratory infections.
Potential Risks and Precautions of Daily Consumption
While highly beneficial for most people, daily natto consumption comes with important considerations:
Blood-Thinning Medication Natto's potent nattokinase enzyme acts as a natural blood thinner. Individuals on anticoagulant medications like warfarin should consult their doctor before adding natto to their diet, as it could increase the risk of bleeding. The high vitamin K2 content can also interfere with these medications.
Thyroid Issues Soybeans, the base for natto, contain compounds known as goitrogens, which can interfere with thyroid function. While unlikely to be an issue for healthy individuals, those with an impaired thyroid function (like hypothyroidism) may need to limit their intake and should consult a healthcare provider.
Allergies and Digestive Distress As a soy-based product, natto should be avoided by anyone with a soy allergy. Additionally, the high fiber content might cause gas or bloating, especially for those not accustomed to it, so starting with small portions is recommended.
How to Incorporate Natto Into Your Daily Diet
For beginners, the pungent smell and sticky texture of natto can be challenging. However, there are many ways to make it more palatable and incorporate it into your daily meals. The classic method involves stirring it vigorously and serving it over warm rice with soy sauce and mustard.
- Classic Natto Gohan: Mix one packet of natto with the accompanying soy sauce and mustard. Stir until frothy. Serve over a bowl of warm rice, topped with chopped green onions.
- Natto Toast: For a quicker option, spread natto on a piece of toast and top with avocado or a fried egg.
- Natto Miso Soup: Stirring natto into a bowl of warm miso soup is a simple way to add nutrition and temper its strong flavor.
- Natto Bowl: Create a savory bowl with natto, brown rice, fresh vegetables, and a drizzle of olive oil for a balanced and nutritious meal.
Comparison Table: Natto vs. Other Fermented Foods
| Feature | Natto | Kimchi | Yogurt (with probiotics) |
|---|---|---|---|
| Source | Fermented Soybeans | Fermented Cabbage & Vegetables | Cultured Milk |
| Key Probiotic Strain | Bacillus subtilis var. natto | Lactobacillus spp. | Lactobacillus, Bifidobacterium |
| Rich Source of Vitamin K2? | Yes (Richest food source) | No | Yes (in grass-fed dairy) |
| Contains Nattokinase? | Yes | No | No |
| Texture | Sticky and Stringy | Crunchy and Spicy | Creamy |
| Flavor | Pungent, Earthy, Savory | Spicy, Sour | Tart, Mild |
| Protein Content | High | Low | Medium |
Conclusion
For most healthy individuals, eating natto every day is not only safe but also offers substantial health benefits, particularly for heart and bone health due to its unique vitamin K2 and nattokinase content. Its probiotic profile also provides significant advantages for gut and immune function. However, those on blood thinners, with thyroid issues, or with soy allergies must exercise caution and consult a healthcare professional. For those new to its acquired taste, starting with small, well-seasoned portions is the key to reaping the rewards of this Japanese superfood.
Authoritative Sources
Healthline: Natto: Nutrients, Benefits, and More. https://www.healthline.com/nutrition/natto Healthline: Natto: Nutrients, Benefits, and More. https://www.healthline.com/nutrition/natto Everyday Health: Natto Guide: Nutrition, Benefits, Side Effects, and More. https://www.everydayhealth.com/diet-nutrition/natto/guide/ Revolution Fermentation: Benefits of natto according to science. https://revolutionfermentation.com/en/blogs/tempeh-soy-grains/health-benefits-natto/ Rhapsody Natural Foods: Natto. https://rhapsodynaturalfoods.com/home/natto/
