Abstract
The daily intake of total dietary fiber (TDF) was evaluated from data of the National Nutrition Survey in Japan for 41 years since 1947. Relationships between the nutrient intake, including TDF, and the rate of mortality or prevalence of diabetes mellitus (DM) were calculated by a time-series correlation coefficient.
1) TDF intake per capita decreased rapidly from 27.4 g in 1947 to 15.8 g in 1963, and subsequently decreased by a lesser extent to 15.3 g in 1987.
2) The prevalence of DM shows a significant positive correlation with both the intake of animal protein and of total fat. The time-series analysis indicates that the prevalence of DM was negatively correlated with TDF with a 6-to 17-year delay, the maximum correlation existing with a 10-year lag (γ=-0.939, ρ<0.001). The TDF intake was less than 16.0 g in 1965, and at about the same time, the prevalence of DM increased rapidly.
3) The crude mortality from DM was negatively correlated with TDF with a 0 to 17-year delay, reaching a maximum correlation with a 17-year lag. The TDF intake was less than 16.5 g in 1962, and at about the same time, the crude mortality from DM increased rapidly.
It is suggested that the cause of the increased prevalence of DM in Japan is positively related to the increased intake of fat and protein. In addition, the decrease in TDF intake has accelerated the prevalence and mortality of DM after a time lag.
