Natto Nutrition

What is Natto

Natto might be the healthiest superfood on the planet. It is a fermented soybean food from Northeastern Japan. The bacteria Bacillus subtilis, on average, ferments the soybeans in about 24 hours.

The fermentation of the soybeans creates the Natto. The fermentation process converts some of the carbohydrates to beneficial probiotic bacteria and other super healthy vitamin-like nutrients.

The bacteria used in the fermentation of Natto is called Bacillus subtilis var. natto. The Natto bacteria creates an odorous, slimy film on the outside of the soybean and the taste is “different” to say the least. The smell is similar to fermenting beer.

It’s hard to describe the taste, it is unique. I have heard it described as strong, earthy and a little like nutritional yeast. It is very rich and filling, I have never been able to eat more than a quarter cup at one time.

The texture of natto is also unique. It is slimy and gooey and when you stir it up it forms almost a gelatin-like paste with the beans. It forms a spider web-like strings when you try to separate it.

Make sure you have a lot of napkins when you eat Natto.

History: The story goes like this: Around 1086 AD the Japanese Samurai clan Minamoto no Yoshiie were attacked while boiling soybeans for their horses. They quickly packed up the beans in straw bags and threw them on their horses. 


A few days later the body heat from the horses fermented the soybeans into Natto. The Samurai warriors were famished and ate the fermented soybeans, and liked them.

Health benefits of Natto

The health benefits of Natto are pretty amazing. Nattokinase is emerging science and I am starting to actually see nattokinase supplement capsules sold in the health store.

Natto is loaded with vitamin K2 in the form of MK-7.
Vitamin K2

Nattokinase and K2 supplements are not cheap, approximately $60 for a 30 day supply combined. Natto is very nutrient dense. You could get (approximately) the same amount on K2 and nattokinase in 2 pounds of dry soybeans fermented into Natto.

Amazon has non GMO (Laura Soybeans) for $16.99 for 5 pounds.

This stuff is so rich and pungent you probably couldn’t eat more than a 1/4 cup at one time even if you wanted to.  

The nutritional content of 1/4 cup of Natto:

  • Total Fat 4.81 g
  • Saturated Fat 0.70 g
  • Polyunsaturated Fat 2.72 g
  • Monounsaturated Fat 1.06 g
  • Cholesterol 0
  • Sodium 3 mg
  • Total Carbohydrate 6.3 g
  • Dietary Fiber 2.4 g
  • Sugars 1.6 g
  • Protein 7.8 g

Natto has more vitamin K2 than any other food on earth. This study on Pubmed titled, “Intake of fermented soybean (natto) increases circulating vitamin K2 (menaquinone-7)” suggests that intake of fermented soybean (natto) increases serum levels of MK-7 significantly.

The MK-7 version of K2 is superior and Vitamin K2 contributes to bone health, prevents cardiovascular disease and could prevent Alzheimer’s disease. Natto also contains large amounts on Nattokinase.

Nattokinase (NK), is an ultra-powerful blood-clot dissolving protein used for the treatment of cardiovascular diseases.

This study on Pubmed shows Nattokinase can prevent blood clots, improve blood circulation, reduce hypertension, prevent stroke, and reduce the chances that you will get Alzheimer’s disease and atherosclerosis.

Most people think cholesterol causes arterial blockages and strokes/heart attacks. However, Vascular calcification is actually the primary predictor of cardiovascular morbidity and mortality.

This study on PubMed titled “Effect of vitamin K2 supplementation” shows that vitamin K2 actually reduces vascular calcification.

The fermentation of the soybeans along with the high fiber in the beans adds both prebiotics and probiotics to you stomach microbiota. Natto has a huge benefit of improving digestion and preventing Keto Constipation.

I think it’s safe to say Natto is an amazing Superfood.

How do you Make Natto?

It’s pretty easy to make Natto actually. First, get you some soybeans. Try to use the smaller, non-GMO, organic soybeans. The common soybeans mass produced today is not healthy because they contain a lot of herbicide (glyphosate) and pesticide residue.

Glyphosate-tolerant GM soy is the number one GM crop plant. The herbicide glyphosate is the most widely used herbicide in the world. The (GM) soybeans are genetically modified to resist glyphosate (Roundup Ready).

According to this article on Science Direct titled, “Glyphosate accumulates in Roundup Ready GM soybeans.” Roundup Ready GM soybeans contributed to 75% of the total soy production in 2011.

Soybeans for Natto
Soybeans for Natto

Here are the steps to make Natto:

  1. Wash beans thoroughly.
  2. Soak beans in water and apple cider vinegar for 24 hours.
  3. Rinse and empty water.
  4. Boil beans or use a pressure cooker until beans are soft.
  5. Drain beans, but leave a little moisture in with the beans.
  6. Wash, rinse and sterilize hands, containers and utensils with distilled cleaning vinegar.
  7. Put warm, but not hot beans in a shallow glass pan.
  8. Inoculate beans with established Natto or use starter culture and stir.
  9. Keep beans warm between 100-115 degrees for about 26 hours. Heating pad on low works well.
  10. Cover beans while fermenting with saran wrap, but poke holes so beans can breathe.
  11. Cover with a towel or blanket to retain heat and keep out the light.
  12. After fermentation, allow to cool slowly to room temperature and refrigerate.

Natto can be refrigerated for 2-3 weeks and also be frozen and safely kept for months.

How to Make Natto

How do you eat Natto

Any way you want. No seriously, the traditional Japanese way is to mix it up with soy sauce and mustard and chopped green onions. It’s a full meal in of itself, but also works as a side dish.

I highly recommend adding Natto to your Keto Diet Food list.

Mixing the Natto with cauliflower rice is a good Keto friendly way to eat it. It’s cheap, absolutely healthy and easy to make.’ almost as if it is the perfect food for human health. That is if the taste wasn’t that important to you.

Robert Bryant


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