Investigations were made on the relation between regional difference in the mortality from apoplexy, a characteristic of Japanese death from this disease and the dietary life, and the following results were obtained.
(1) Salt was named first as a nutritive element relating to the regional difference. It was found that regional difference in the salt intake was marked, and large amounts (more than 20Gm.) of salt were taken in the north-eastern district where the mortality from apoplexy and the level of blood pressure of the inhabitants were high.
(2) It was clarified that the Japanese salt intake was influenced by the Japanese dietary habit to eat rice with miso soup and pickles and to use soy-sauce as a seasoning. Regional difference in the salt intake was due to regional difference in salt contained in miso and pickles.
(3) Investigations were made on the relation with K, a factor to give influences to the relation between high blood pressure and the salt intake. The fact that the mortality from apoplexy and blood pressure were comparatively low in the. apple producing regions of Aomori Prefecture, though it was also in the north-eastern district, suggested that eating apples containing abundant K had something to do with this phenomenon, and the author emphasized the necessity to give consideration to balance between Na and K in the daily dietary life.