Longevity and diet in Okinawa, Japan: the past, present and future

Japan has the longest life expectancy at birth (LEB) in the world. Okinawa, Japan's poorest prefecture, previously had the highest longevity indices in the country. However, the latest LEB for men in Okinawa is no higher than the national average. The purpose of this study is to examine why the longevity indices in Okinawa were once the highest in Japan, and to examine the reasons for their recent decline. In 1990, in Okinawa, the age-adjusted death rates (ADR) of the three leading causes of death were lower than their national averages. By 2000, the standard mortality ratios (SMR, Japan=100) of heart disease and cerebrovascular disease for both sexes in Okinawa had increased, compared to their 1990 levels. Both of the ADR of ischemic heart disease and the ADR of cerebrovascular disease for men increased to 45.5 and 63.5 in 2000, up from 42.9 and 59.1 in 1990, respectively, and the SMR of ischemic heart disease for men in Okinawa reached 101 in 2000. Consequently, the national ranking of Okinawa prefecture for LEB of men has dropped. As of 1988, in Okinawa, daily intake of meat and daily intake of pulses were both approximately 90 grams, which is about 20% and 30% higher than the national average, respectively. Also, as of 1988, daily intake of green and yellow vegetables in Okinawa was about 50% higher than the national average. However, by 1998, daily meat intake and fat energy ratio had surpassed 100 grams and 30%, respectively, and daily intake of pulses and green and yellow vegetables had declined to the level of the national average. Recently, young Japanese, particularly young men in Okinawa, have shown a tendency to avoid the traditional dishes of stewed meat and champuru.