Epidemiology and prevention of hypertension in Japanese: how could Japan get longevity?

Japan is one of the countries with the longest longevity in the world, and it was accomplished by a drastic decline in stroke mortality from 1960’s. The decline in stroke mortality would be largely explained by a population-wide decreasing trend in blood pressure (BP) level, because higher BP has been the strongest risk factor of stroke; about 20% of total deaths can be explained by higher BP above optimal in Japan. Decreasing trend in BP occurred both in men and women in all age-groups, which cannot be fully explained by the widespread use of anti-hypertensive agents. The most probable reason for the population-wide BP decline in Japan would be a large decline in dietary salt intake after 1950’s. However, other factors including obesity, high alcohol intake, and unfavorable dietary habits could increase BP level of Japanese again.