Natto

Also known asFermented Soybeans · 納豆 · 纳豆

Name: Natto — a Japanese food of whole soybeans fermented with the bacterium Bacillus subtilis var. natto, forming a sticky, stringy, slimy coating and a strong, pungent, ammonia-like smell and nutty, savoury taste. It is usually eaten at breakfast, over rice.

Description

Natto has been eaten in Japan for about a thousand years, and is especially popular in the north-east and the Kanto region, and less loved in western Japan. Legend says it was discovered when a samurai's boiled soybeans, wrapped in rice straw, fermented by accident on a horse's back. It is sold in small polystyrene tubs with mustard and soy-sauce sachets.

Traditionally, the beans are stirred vigorously until they form long, sticky strings, which many people find off-putting but fans love. It is considered a health food in Japan, being rich in vitamin K2 and nattokinase, an enzyme studied for effects on blood clots.

Main nutrition value

Natto is an excellent source of plant protein, fibre, iron and manganese, and is exceptionally rich in vitamin K2 (menaquinone-7) and probiotic bacteria.

How best to be consumed

Natto is eaten cold, stirred, over rice.

1. Stir the beans vigorously with a pair of chopsticks until stringy, then mix in the mustard and sauce, and serve over hot rice.
2. Top with spring onion, raw egg yolk, kimchi or grated daikon.
3. Add to sushi rolls (natto maki), toast, noodles or omelettes.
4. Eat it fresh, and keep in the fridge, or freeze for longer storage.
5. Start with a small amount if you are new to it.

Overconsumption could cause…

Natto is nutritious, but one of the most important foods for people on warfarin to know about.

1. Strong interaction with the blood-thinning medicine warfarin, since the very high vitamin K can cancel its effect, so people on it should avoid natto unless a doctor says otherwise.
2. Soy allergy, which can be serious in some people, particularly children, so anyone allergic must avoid soy and check labels.
3. Possible effects on thyroid medicine absorption, so people taking levothyroxine should leave several hours between it and soy foods, and soy can matter for people with low iodine intake or an underactive thyroid.
4. Biogenic amines such as tyramine, which can affect people on MAO inhibitors.
5. A smell and texture that many people find unpleasant, and high purines in people with gout.

GroupsFermented SeasoningsSoy FoodsLegume familyHigh proteinLow sodiumRich in ironRich in magnesiumRich in potassiumRich in vitamin KRich in zincJapaneseFermented

Made fromSoybeans

Related foodsMisoTamariSoy SauceTempehFermented TofuEdamame

Wikipedia — Nattō, used for origin, naming and history: https://en.wikipedia.org/wiki/Nattō