Rumor:

According to Japan's TV Asahi reported on the 11th, the new crown pneumonia outbreak since the occurrence of the Ibaraki Prefecture in Japan, where natto is abundant so far there has not been a case of the new crown virus infected people, so many Japanese people believe that the natto has the effect of preventing the epidemic.

Discredited:

According to Japan's TV Asahi reported on the 11th, the new coronary pneumonia epidemic since the occurrence of Ibaraki Prefecture, Japan, due to the abundance of natto so far there is no case of the new coronary virus infected, so many Japanese people believe that the natto has the effect of preventing the epidemic. As a result, there has been a rush to buy natto in many parts of Japan.

Photo from Weibo screenshot

What exactly is natto? Why is it so popular among Japanese people? Can natto really play a role in preventing pneumonia?

1. What is natto?

On the Internet, it is said that natto is Japan's "national treasure", in Japan has a history of more than 1,000 years. Japanese people even have a saying: "Natto Dun Dun have, live to ninety-nine". But in fact, natto originated in China. Natto is traditionally made from naturally fermented rice straw. Since it was first made in the kitchen of a temple, which was called a "nasho," it was called "natto.

Natto was introduced to Japan around the time of Ganjin's visit to the east in the Tang Dynasty, and was first eaten by monks, but later evolved into a nutritional supplement for the Japanese royal family, nobility, and samurai.

The Japanese later isolated from it the bacteria that turn soybeans into natto, known as natto bacillus (a type of Bacillus subtilis). Modern natto production can be carried out using purified cultured natto bacteria for easier and more controlled production. Thanks to the tireless research of Japanese scientists, natto has been developed in Japan, and it is gradually being recognized as a uniquely Japanese food.

In fact, even today, there are foods in China that are particularly similar to natto. For example, edamame from the southwestern part of the country is made much like natto, in that it is also made by boiling soybeans and then fermenting them.

2. Does natto have any special nutrition?

Natto is a food made from fermented soybeans. After fermentation, the soybeans undergo some changes, and the nutrition of natto is also different.

First, the protein digestibility of Natto increases. The protein digestibility of soybean itself will be lower, but after fermentation into natto, some of the protein will be broken down into smaller molecules, and some amino acids will be produced, which will be more convenient for the body to absorb.

But the total amount of protein doesn't change much. However, almost all soy products have similar changes after fermentation, our tempeh has the same effect, and natto is nothing special.

You can see that the nutritional value of natto is not very different from that of soy itself, overall.

Secondly, natto produces some vitamins during the fermentation process. For example, vitamin K, riboflavin, and vitamin B12 are one of its advantages. However, this is also common in all other bean fermented foods, such as Chinese tempeh also has natto is not special.

In addition to this, some flavor substances are produced, giving natto a special flavor. However, this flavor is not very pleasant and many people don't like it, and, this has little impact on nutrition.

Overall, after fermentation, there is little change in the overall nutritional value of natto, but more of a change in flavor.

It's not these things that make natto so widely admired, but an active enzyme, nattokinase.

3. Nattokinase, what's the magic?

Online on the legend of the Japanese residents of longevity, and often eat natto related; said natto blood pressure and fat reduction effect is remarkable, some people go to Japan to travel to bring natto back specially. Said natto can prevent the new coronavirus, eighty percent is also because of it. Nattokinase in the end what is it? Really have so many magical role?

The Japanese have always felt that natto is good, and they want to explore what ingredients are in it. 1980s, Japanese scholar Hiroyuki Sumi found a thrombolytic function in natto, and named this enzyme "nattokinase" (Nattokinase), which is an enzyme that is found in the blood of kelp. , which is formed under the fermentation of the bacterium Bacillus subtilis.

Scientists have also carried out various studies around Nattokinase, and some experiments have found that it has some positive effects in the prevention and treatment of cardiovascular and cerebrovascular embolism, embolic Alzheimer's disease, and the regulation of immunity. But all these results still need to be demonstrated, not to mention the fact that eating natto can prevent neocoronitis.

First, natto is not the same as nattokinase. After all, nattokinase is a protein that is mostly broken down when taken orally, and usually doesn't maintain its spatial configuration, much less its activity. While some studies have found it to be somewhat active when it enters the body as well, the jury is still out in the scientific community.

The European Food Safety Authority, EFSA, has evaluated nattokinase products, and from the evidence so far, it has not been possible to confirm that oral intake can be sufficient to have active nattokinase.

Secondly, the results of research on nattokinase are very preliminary. Most of the current research on the health benefits of nattokinase has been in vitro experiments; there is still too little evidence from human studies, and the results are all very preliminary. Crucially, there is even less research evidence on nattokinase and the new coronavirus.

Also, nattokinase is not found only in natto. Nattokinase is produced by the bacterium Bacillus subtilis during the fermentation of soybeans. The enzyme, or an enzyme with similar activity, can be produced wherever Bacillus subtilis or a similarly active bacterium is present.

For example, the same or similar enzymes are found in fermented soy products such as Chinese tempeh and Korean dashi. But because they have been named "nattokinase," many people think they are unique to natto. Therefore, even if you want to get nattokinase, there is no need to grab natto.

Overall, there is not enough evidence to show that eating natto can dissolve blood clots, lower blood lipids, improve immunity, want to rely on it to resist the new coronary virus, it is too imaginative, the behavior of robbing the natto is too foolish. I hope we can all remain rational in the face of the epidemic, more science.

4, to eat natto?

Natto is a fermented soybean products, in the fermentation process will occur some favorable changes, such as the production of a variety of amino acids, which helps to improve the utilization of protein, but also produces a number of B vitamins, such as B12, which is particularly beneficial to the vegetarian population.

Additionally, a large number of studies have found that there are health benefits to eating soy products. Our dietary guidelines recommend eating 25-35 grams of beans per day, and natto can be a good source of beans.

So, if you like natto, eat it. Just don't count on it to prevent new crown pneumonia; it's better to protect yourself, wear a mask, and wash your hands regularly.

Of course, other soy products, such as tempeh, tofu, and soybean skins are all great soy products, so don't fall in love with natto alone.

Discrediting expert: Ruan Guangfeng, director of the Science and Technology Department of the Center for Food and Nutrition Information Exchange (CFNIE)