Natto
fermented
Natto is a traditional Japanese food made from whole soybeans that have been fermented with Bacillus subtilis var. natto. It is often served as a breakfast food with rice. It is served with karashi mustard, soy or tare sauce, and sometimes Japanese bunching onion. Within Japan, natto is most popular in the eastern regions, including Kantō, Tōhoku, and Hokkaido.
Conditions addressed
How to use
- Consume 1–2 tablespoons daily as a condiment or side dish.
- Do not heat — high temperatures destroy live cultures.
Pregnancy, Breastfeeding & Children
No herb-specific pregnancy/child safety research is documented for Natto in our references — the guidance below is based on its general effect category, not research on Natto itself. Always confirm with a midwife, doctor, or pediatrician.
Pregnancy
Use CautionThis herb may affect blood pressure. Since blood pressure changes are a significant pregnancy risk factor (e.g. preeclampsia), herbs in this category are generally used only under medical supervision rather than self-directed — this is a general, mechanism-based caution, not herb-specific research.
Breastfeeding
Use CautionGenerally used cautiously during breastfeeding, particularly if the nursing parent is also on blood pressure medication.
Children
Use CautionBlood-pressure-active herbs are generally used cautiously in children and typically only under pediatric guidance.
Interactions & contraindications
May affect blood pressure
Watch for: Antihypertensive medications (ACE inhibitors, beta-blockers, calcium channel blockers, diuretics)
Combined use can push blood pressure too high or too low — monitor readings if you take blood pressure medication.
May thin the blood
Watch for: Anticoagulants (warfarin), antiplatelets (aspirin, clopidogrel), and other blood-thinning herbs or supplements (ginkgo, garlic, fish oil, vitamin E)
Combining blood-thinning substances can increase bleeding risk, including before surgery or dental work.