Natto: a super superfood

【What is natto】

Natto is a traditional Japanese dish that is made by fermenting soybeans; it is characterized by its stringy, slimy texture(similar to okra) with a distinct odor, and nutty flavor. Although having a strong odor, it's nutty flavor is very subtle and it easily takes to added flavors.

In Japan natto is typically enjoyed with tare(a sauce usually consisting of soy sauce, bonito dashi, sake, and mirin), Japanese mustard, green onions, and served over rice as a rice bowl. Over the years this has changed, and now is widely accepted to be served in a broad variety of recipes. Check out some easy recipes here!

【Nutritional value of natto】

Natto THE superfood of Japan, is a food that contains a large amount of nutrients, protein, vitamins, and dietary fiber, just to name a few, that are important to maintain a healthy body.

Below is a breakdown of the main nutrients that one serving(50g - 1¾oz) of natto contains.

 

【One serving of natto 50g(1¾oz)(Yoshi Natto ¼pack)nutrition contents】

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The nutrients listed in the figure above are the nutrients that natto contains a higher content than other food products. It is also rich in other nutrients such as Vitamin B6, Vitamin E, potassium, calcium, and folic acid.

 

【Health Benefits of Natto】

Improved Digestion

The dietary tract of humans have trillions of micro-organisms/bacteria to help you digest your food. Having the right type of bacteria in your gut is linked to numerous health benefits, from improved digestion, and immune system to help with several bowel related diseases and gastrointestinal symptoms such as gas, constipation, diarrhea, and bloating.

To build a healthy gut flora it is essential to take probiotics, which most probiotic-rich foods and supplements contain 5-10 billion colony-forming units(CFUs, a unit of measure that estimates the number of healthy bacteria) per serving, whereas natto can contain up to 1 billion CFU in only 1 gram.

Added to this, because natto is made from soy, it is also rich in prebiotics. The human body can not digest prebiotics, but they are important food for probiotics, and help the growth of beneficial bacteria which in turn helps maintain a healthy gastrointestinal environment.

It is important to note that ingested probiotics do not affect the gut flora long term, and are likely return to pre-probiotic condition within one to three weeks. So it is essential to keep eating probiotic-rich foods to maintain a healthy gut!


Healthier Heart

Natto contains fiber and as mentioned above high levels of probiotics, both which contribute to lower cholesterol levels. Additionally the fermentation process of natto produces an enzyme called natto-kinase, which has the highest anti-clotting activity compared to other enzymes, as well as vitamin K1 which also has an important role in blood-clotting; this helps to prevent strokes and heart attacks, and improves blood flow.

Furthermore, although there is not enough clinical research done(only a few clinical trials) to prove the following effects, it is believed that natto-kinase helps with

  • lowering blood pressure

  • decrease cholesterol and triglyceride levels

  • reduce calcium deposits and plaque size that causes hardening of arteries

Unlike Bacillus Natto, natto-kinase start to breaking down at around 50℃/ 122℉, so to ensure the full health benefits of natto, it is best to be eaten without cooking.


Boosts Brain Functions

Natto is loaded with compounds such as vitamin B1, B2, and K2, which help slow aging of the brain, and help reduce complications of the nervous system. Along with this, as stated above, natto is an extremely probiotic-rich food which along with all the other health benefits will help reduce stress, improve memory, and reduce symptoms of anxiety, depression, autism, and obsessive compulsive disorder.

Although there has not been enough clinical testing, it is believed that the consumption of natto-kinase helps control elements that characterize Alzheimer's disease. It is also known to unravel protein fibrils associated with Alzheimer's as well.

Lastly, as natto is a soy product, it contains plenty of lecithin, which is a substance that helps improves memory, rejuvenates the brain and aids in combating the early stages of senility. Another substance from soy are isoflavones which help regulate the release of hormones.


Improve your immune system

As natto is a probiotic-rich food, it contributes to a healthy gut flora, which in turn contributes to suppression of the growth of harmful bacteria, and can boost the production of natural antibodies. Furthermore probiotics reduce the risk of infections, needing antibiotics for recovery from infections, and to boost recovery times if you do get sick. In addition to this natto is also a good source of vitamin C, iron, zinc, selenium and copper, all which aid in a stronger immune system.

As well as soy saponin in soy beans is an important ingredient for white blood cells that make up the bulk of your immune system; also, along with soy saponin polyglutamic acid in soy beans helps with the removal of toxic substances from the body.


Stronger Bones

Natto has many nutrients that build healthy bones. Although it does not contain as much calcium as milk, one serving(50g) contains 11% of the recommended daily intake; calcium is the main mineral, the core building block of your bones. On top of this as mentioned above, natto is one of the few plant sources for vitamin K2; it aids in the activation of bone-building proteins which help your bones absorb calcium, and prevents calcium from being leached from bones. This process helps to slow the age-related loss in bone density, and osteoporosis.


Other Health Benefits

-Helps to maintain healthy, smooth skin: natto is rich in Vitamin E, and PQQ

-Known to lower the risk of cancers: natto is rich in Soy isoflavones and vitamin K2, both which may be linked to lower risks of liver, prostate, digestive and breast cancer.

-May help in weight loss: natto is a good source of probiotics and fiber, which help in optimizing gastrointestinal health.

Due to the overwhelmingly positive health benefits of natto, it is believed that the long healthy life expectancy of Japanese people are the result of their regular consumption of natto; due to the lack of clinical data on the health benefits of natto, it has not yet been 100% ascertained that these are directly corelated, but there are many studies currently underway to analyze the true benefits of natto.

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【When NOT to eat natto】

Although natto is generally safe to eat for most people, because it contains both natto-kinase and vitamin K1(not the same as vitamin K2) both of which have blood-thinning properties, if you are taking blood-thinning medication(E.G. Warfarin, Heparin, Fondaparinux, Rivaroxaban, etc.), it is recommended to talk to your family doctor before adding natto to your diet.

**In one serving(50g/1¾oz) of natto there is on average 435㎍ of vitamin K and 1500FU of natto-kinase

【Natto FAQ】

 

Q)Is it okay to freeze natto?

A) There is no issue with freezing natto. Most natto that can be bought at grocery stores are sold frozen. The Bacillus Natto bacteria is EXTREMELY resilient and are able to survive extreme temperatures from -100℃/-148℉ up to 120℃/248℉. Thus you can gain plenty of the health benefits that natto has to offer even after freezing. However, like all frozen foods many of the water soluble vitamins will break down, and some of the flavor is lost compared to fresh natto.

Even so depending on what natto is paired, you can add lacking nutrients or boost the efficiency of nutrient absorption. If you are worried about the lost nutrients please check out the "Food Combinations" below to see the best pairings for natto!


Q)How Should I eat natto?

A)Natto is traditionally enjoyed as a rice bowl with green onions, tare(a soy sauce based sauce with, bonito dashi, sake and mirin), Japanese mustard, and a raw egg.

This has changed overtime to encompass many food types and recipes. You can check some easy recipes from below!


Q)Is it true that I should eat natto at night?

A)Natto-kinase has blood-thinning properties which help in breaking down blood clots; this effect is seen to be effective for about 12 hours after consumption. It is said that because blood clots have a higher change of forming after 4 hours of inactivity(I.E. sleep) it is best to have natto at night to combat the increased chance of blood clotting!

Q)There is a white film/coating on the natto...is it safe?

A)This is a film of Tyrosine(a type of amino acid) that is produced during fermentation. Which is completely safe to eat, and actually helps with the production of dopamine, melanin, epinephrine, norepinephrine!


Q)Is it bad to heat/cook natto?

A)The Bacillus Natto bacteria, as stated before, is extremely resilient and can withstand temperatures up to 120℃/248℉, so you will not loose out on the health benefits from BN bacteria, but unfortunately natto-kinase starts to breakdown at around 50℃/ 122℉, so to ensure the full health benefits of natto, it is best to be eaten without cooking!


Q)How long does natto last?

A)Frozen natto is usually recommended to be consumed within 6 months. Fresh or defrosted natto is recommended to be consumed within 5 days.


Q)Is it safe to eat natto after the best by date?

A)Just because it is passed the best by date, does not make it dangerous to consume, especially if frozen. If frozen it will get freezer burnt, and lose most of its vitamins, and flavor after the best by date, and if defrosted as time passes the more natto will ferment, and give off a stronger pungent ammonia odor. Thus we usually do recommend eating natto that has been left for over 10 days.

We do not recommend eating natto that has lost its stringiness as this may be a sign of contamination of other unhealthy bacteria, and we definitely do not recommend if there are signs of mold, as this is a definite sign of contamination of potentially dangerous pathogens.