Natto

Nutrition · per ~90 g serving · ≈ ½ cup cooked

Score · 90/100

Overview

Natto originates from Japan, where it has been a dietary staple for over 1,000 years. During fermentation by Bacillus subtilis, soybeans undergo a remarkable biochemical transformation: proteins become more bioavailable, complex carbohydrates are partially broken down, and—most notably—vitamin K2 (menaquinone) is synthesized de novo. A 100g serving provides 211 calories with nearly 20g of complete plant protein, substantial micronutrients including iron (8.6mg), and bioactive compounds including nattokinase, a fibrinolytic enzyme with emerging cardiovascular benefits. The fermentation process also generates live probiotics and GABA, both linked to gut and neurological health. For longevity-focused nutrition, natto's combination of K2, complete protein, and fermented bioactives makes it exceptionally valuable—particularly for populations with limited access to K2-rich animal products. The sticky mucopolysaccharide coating (produced during fermentation) may support digestive resilience. Natto's umami-rich flavor makes it a functional food that enhances palatability of nutrient-dense meals without added sodium.

Health Benefits (5)

• Supports bone mineralization and cardiovascular calcification prevention via vitamin K2

  moderate
  Vitamin K2 (menaquinone) activates osteocalcin and matrix Gla protein, proteins essential for directing calcium to bones rather than arterial walls
• Provides complete plant-based protein with all nine essential amino acids

  strong
  Fermentation increases amino acid bioavailability and reduces antinutrient factors like phytates, enhancing protein digestibility to near animal-protein levels
• Supports fibrinolytic activity and healthy blood viscosity via nattokinase

  emerging
  Nattokinase, a serine protease produced during fermentation, may help dissolve excess fibrin and support healthy blood flow
• Promotes healthy gut microbiota composition via probiotics and prebiotic carbohydrates

  moderate
  Live Bacillus subtilis and partially fermented oligosaccharides feed beneficial bacteria, supporting intestinal barrier function and immune signaling
• Supports cognitive and mood health via GABA and choline content

  moderate
  Fermentation generates GABA (a calming neurotransmitter), while 57mg choline per 100g supports acetylcholine synthesis and brain cell membrane integrity

Food Pairings

• ·Pair with brown rice or soba noodles because their complex carbohydrates slow gastric emptying, extending nutrient absorption and moderating blood glucose response
• ·Combine with raw leafy greens (spinach, arugula) because natto's vitamin K2 works synergistically with K1 from greens for comprehensive bone and vascular support
• ·Serve with fermented vegetables (kimchi, sauerkraut) because complementary probiotic species enhance microbial diversity and reinforce intestinal barrier integrity
• ·Mix with avocado or olive oil because natto's fat-soluble vitamin K2 absorption is enhanced by dietary lipids

Practical Tips

• ·Purchase frozen natto packages and thaw overnight in the refrigerator; freeze immediately upon arrival if not used within 2-3 days, as Bacillus viability declines with age
• ·Mix natto vigorously for 30-50 seconds before eating to maximize the development of mucopolysaccharides and activate nattokinase; stir with the provided condiment packet for optimal flavor and umami enhancement
• ·Consume natto in its raw, unheated form to preserve heat-sensitive probiotics, nattokinase activity, and vitamin K2; heating above 70°C significantly reduces bioactive enzyme activity
• ·Start with a small portion (1-2 tablespoons) if new to natto to allow digestive adaptation; some individuals experience temporary bloating as the microbiome adjusts to increased fermented foods
• ·Store unopened packages in the freezer (below -18°C) for up to 6 months; once thawed, keep refrigerated and consume within 24-48 hours for optimal probiotic viability

Optimal Timing

Natto's complete protein, probiotics, and K2 support multiple physiological processes that benefit from distributed intake throughout the day. However, consuming with meals (especially breakfast or lunch) maximizes fat-soluble K2 absorption and provides sustained protein availability for satiety and muscle protein synthesis.

While technically compatible with fasting, consuming natto during eating windows ensures optimal nutrient absorption, particularly for fat-soluble vitamin K2