Osteoporosis in Japan: factors contributing to the low incidence of hip fracture.

Abstract

Hip fracture incidence seems to be lower in Japan than in many Western countries, but the difference is apparently becoming smaller with progressive Westernization of the Japanese lifestyle and nutritional habits. Nutrition cannot explain the lower incidence of hip fracture. A lower calcium intake prevails in Japan. Genetic differences in body build, including a lower center of gravity, better motor function and agility, well developed hip musculature and small but more fracture-resistant bones secondary to a difference in life- and work-style may contribute to fewer falls and a lower fracture rate among Japanese than among their Western counterparts. Such traditional lifestyle habits as sitting directly on the floor are rapidly decreasing, and time will tell how much of the low incidence of hip fracture in Japan can be explained by lifestyle and how much by genetic and other factors. The Japanese women who now enjoy a low hip fracture incidence led a hard physical life when they were young. This may be a lesson to the young of future generations in how to avoid bone fractures when they are old. Bone health may be achieved by enjoying life through sports or even the tea ceremony in place of the hard physical work of their ancestors, which is gradually disappearing.