what are the health benefits of natto? – Japanese traditional superfood

what are the health benefits of natto? – Japanese traditional superfoodarticles

In this post, I will discuss what are the health benefits of natto. Natto is a traditional Japanese fermented soybean. Although some people don’t like the smell of natto, most Japanese love to eat natto. I am in love with Natto. Not only the delicious taste, but natto is also very healthy for your body.

What is natto?

Natto is a fermented soybean in Japan. By growing natto bacteria (Bacillus subtilis var. natto) on the surface of boiled soybeans in about 40°C for 24 hours, soybeans create sticky substances and start to express the distinct scent of natto.  When natto bacteria grow on soybeans, natto bacteria break down protein in soybean and make it easier to digest. Also, natto bacteria produce vitamins and enzymes.

Natto’s fermentation process is much shorter than other fermented soybean products such as miso. It requires only 24 hours.

Origin of Natto

2000 years ago, ancient Japanese were using rice straws to cover the ground in their house. At the time, Japanese people were eating rice and soybeans. When boiled or steamed soybeans fell down onto rice straws in a warm house, the soybeans became natto.

Eventually, Japanese people started to make natto by putting boiled soybeans into a rice straws bag.

what are the health benefits of natto?

Natto is nutritionally fortified soybean by natto bacteria

First of all, Natto is made from soybean, a superfood with abundant nutrients. By eating natto, you can benefit from soybean and its fermentation effects.

Nutrition of soybean

  • Soybean contains all essential amino acids that the human body needs to intake for a proper body function.
  • Soybean contains well-balanced and a rich amount of nutrients such as vitamins, minerals, and antioxidants.
  • Soybean is rich in one of the essential amino acids, lysine, which is less in rice. On the other hand, rice contains a lot of methionine, which is less in soybean. It is interesting that by soybean meeting natto bacteria in rice straw, natto is born, and they complete each other.
  • Soybean is rich in saponin which functions as an antioxidation, anti-aging,  anti-lipemia agent.
  • Soybean is rich in isoflavone, a powerful antioxidant.
  • Soybean is rich in soluble and insoluble fibers.
Is soybean good for you?
Do you know the benefit of soybean? Is soybean good for you? We have been using soybean as a daily diet in Japan ...

Nutrition of natto compared to soybean

  • Protein in Natto is easier to digest than simply boiled soybeans. The digestion/absorption rate for boiled soybean is 65%, whereas in natto it’s 80%.
  • Natto contains 6 times more vitamin B2 (Riboflavin) than boiled soybeans. Vitamin B2 helps to burn your fat. If you are short in vitamin B2, you have more risk of skin inflammation and early aging. Vitamin B2 is an essential nutrient which you need to consume on a daily base.
  • Natto contains vitamin K2 which soybean does not. Vitamin K2 make your bone stronger and is used as a medicine for osteoporosis. Vitamin K2 can reduce the risk of metabolic syndrome.
  • Natto contains nattokinase. Nattokinase prevents thrombosis.

Health benefits of natto

Natto is rich in antioxidants

As far as we breathe in oxygen, we produce reactive oxygen species (ROS) in our bodies. Although ROS plays beneficial roles such as in the immune system, excessive production of ROS hurt cells and cause several chronic diseases such as cancer and heart disease. If your body is healthy, your body can protect itself with the antioxidant defense mechanism. However, when the production of ROS exceeds the capacity of the mechanism, your body is in the state of oxidative stress.

Oxidative stress is known as the possible cause of neurodegenerative diseases such as Parkinson’s disease, Alzheimer’s disease, depression, autism, and Multiple sclerosis, and linked to cardiovascular diseases and cancers.

Natto is rich in antioxidants such as selenium, vitamin E, and isoflavone, saponin, and vitamin B2, and can reduce the risk of these diseases caused by oxidative stress.

Natto prevents Lifestyle disease.

After western fast food restaurants become popular in Japan after the second world war, Japanese consume 7 times more meat and eggs, 15 times more dairy products, and 6 times more fat than before, instead,  30% less rice. Together with animal product consumption increasing, the incidence of lifestyle diseases such as colon cancer, diabetes, heart disease, dyslipidemia, and cerebral infarction have increased. For example, the death rate by cancer increased 4 times than before the second world war.

Fast food is generally low carb and high fat. By eating a high-fat diet, fat in the bloodstream increases, and your body immediately start to get oxidative stress, inflammation, and arterial stiffness according to Physicians Committee for Responsible Medicine. Inflammation and oxidative stress cause lifestyle diseases. Because of the following reasons, natto can prevents lifestyle diseases.

  • Natto contains various antioxidants such as selenium, vitamin E, and isoflavone, saponin, and vitamin B2 and van prevent oxidative stress and inflammation.
  • Saponin also makes blood vessels softer and prevents arterial stiffness and high blood pressure.
  • Nattokinase removes thrombus in a blood vessel and prevents cerebral infarction, stroke, and myocardial infarction.
  • Linoleic acid reduces LDL (Low-density lipoprotein) and prevents arterial stiffness and heart disease.

Natto prevent osteoporosis

In Japan, natto consumption varies across regions because of historical background. According to research, regions where people eat more natto, are lower in bone fracture incidences, whereas, incidences are higher in regions where people consume less natto.

Natto contains vitamin K2, which improves bone formation and prevents bone fracture. Research data showed people who had bone fracture had less vitamin k2 in their blood.

Osteoporosis is more common for post-menopause women because of the production of estrogen, which plays a role in reducing bone breakdown, reduces after menopause.

Isoflavone in soybean is similar to estrogen in its structure and function. By eating natto, post-menopause women increase isoflavone intake and prevent osteoporosis.

Natto reduces a blood sugar level.

When you eat carbohydrates, they break down into sugar and go into the bloodstream, and sugar goes into the cells and is used as an energy source. For sugar to enter into the cell, insulin needs to connect to the receptor on the cell membrane. When you consume excess fat, fat covers your cell and block insulin receptors. As a result, insulin cannot connect to the insulin receptor, and sugar cannot go into cells, and the blood sugar level increases.

Natto contains water-soluble peptide and water-insoluble peptide. A peptide is a compound of multiple amino acids. Both types of peptides are beneficial against high blood sugar levels.

The water-insoluble peptide reduces fat levels in the blood. It reduces the blocking of insulin-receptor and risk of diabetes as well.

The water-soluble peptide stimulates insulin receptors to function better and also increases the number of receptors. Therefore, sugar is more likely to go into cells for utilization.

Natto keeps your brain young

Acetylcholine is a neurotransmitter that plays an important role in memorizing, learning, and physical capability. When the amount of acetylcholine decreases in the brain, it leads to forgetfulness and dementia.

Soybeans or natto contains a rich amount of lecithin which increases the production of acetylcholine in your body. Thus, natto can keep your brain young and prevent dementia.


Natto is a Japanese traditional superfood that provides nutrition to support body function. Although the smell is difficult for some to get used to, once you taste it, you will fall in love with forever, because your body knows what is beneficial for it.

Natto is made of soybeans which is very easy to get and affordable. In addition, you can make natto by yourself. I live in Taiwan, and I make my own natto. In the next blog, I will show you my recipes, so you can start to make your own.


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