Japanese news: on natto, vitamin K and femur fractures

I found an intriguing article today on the Asahi website. The title of the article is :

中高年の骨折は「西高東低」 原因は不明、納豆が関係か.

  • 骨折・こっせつ fracture of a bone

The title says that concerning bone fractures of middle-aged and elderly persons, it is “high in the West and low in the East”. Even if the reason for this difference is unclear 不明, it may be related to the consumption of natto 納豆.

Link to the article

What is defined as “high” or “low” is the proportion 割合・わりあい of persons who broke their femur 大腿骨骨折・だいたいこつこっせつ.

  • 大腿骨・だいたいこつ is the femur or thighbone. Together with 骨折・こっせつ, which means “fracture of a bone”, it means “fracture of the femur”.

Research groups 研究グループ・けんきゅう say that the differences between West and East Japan could be related to eating habits 食生活・しょくせいかつ.

The survey 調査・ちょうさ carried out is based on data coming from the Ministry of Health, Labour and Welfare 厚生労働省・こうせいろうどうしょう. The survey concerned people above 40 who had a femur fracture 大腿骨骨折をした40歳以上の男女.

The goal of the survey was to examine the differences by prefecture: 都道府県別・つどうふけんべつ

  • 都道府県・とどうふけん is a Japanese prefecture. Adding the word 別・べつ, which means “difference”, gives the idea of “differences by prefectures”.

The results of this examination prove that there is a disparity 偏り・かたより (bias, lack of balance) between men and women.  If we compare the prefectures, the proportion of femur fractures is higher in West Japan and lower in East Japan, and this is true for women as well as for men. The article says:


  • 傾向・けいこう tendency, trend, inclination
  • 浮かび上がる・うかびあがる rise to the surface, appear, emerge, come to light

The tendency “West high, East low” emerged (from the results).

The reason 原因・げんいん for such an important regional disparity 地域間の偏り is indistinct, unclear はっきりしていない.

In the past, the (amount of) consumption 消費量・しょうひりょう of natto 納豆・なっとう by Japanese had been given as a reason to explain why Japanese had a high concentration 濃度・のうど of vitamin K in the blood 血中・けっちゅう. Natto contains 含む・ふくむ a lot of vitamin K, which helps to bring the calcium to the bones:


  • 取り込む・とりこむ means “to bring in”. Here, I think we can translate by “to enhance the absorption of calcium into the bones”.

To explain the results of the survey, researchers turn to eating habits.

A professor of Osaka Medical College explains that people should undergo a medical examination 受診・じゅしん, absorb 摂取・せっしゅ calcium, vitamin D, and vitamin K, make a habit 習慣づける・しゅうかんづける of doing sport, and be careful of underweighting やせ過ぎ・やせすぎ.

Even if the article does not comment on the professor’s statement, it tends to show that the mere absorption of natto, or vitamin K, is not enough to prevent femur fractures. It should be supplemented by sport and good eating habits.


The title caught my attention because I like natto and eat it often. I am not particularly interested in nutritional facts, though.

At first, I thought that the article would be very difficult to read. It contained three obstacles:

  1. medical terms (such as 大腿骨骨折)
  2. numbers and words related to surveys, like 割合 or 偏り
  3. name of prefectures

But after looking up a few words and isolating what was important and what was not, it was not that difficult. For example, I didn’t try to translate the results obtained in this or that prefecture. More than the survey itself, I found that the conclusion drawn from the results was interesting, and focused on it.