Masanobu Yamakawa

Different trends in serum cholesterol levels among rural and urban populations aged 40–59 in Japan from 1960 to 1990

In Japan, coronary heart disease mortality is low and has been declining since 1970, despite recent increases in serum cholesterol levels which have been reported in nationwide surveys. Longitudinal and cross-sectional surveys of serum cholesterol levels in rural and urban populations from 1960 to 1990 were reviewed. In the surveys in the 1960s, serum cholesterol levels in urban populations were higher than those in rural populations. An increase in serum cholesterol levels for men and women was observed in all longitudinal studies among rural populations; mean increases in serum cholesterol levels per year were 0.034 mmol/l (p < 0.001) and 0.033 mmol/l (p < 0.001), respectively. These trends were still observed after combining the data from the longitudinal and cross-sectional studies in both men and women (0.027 and 0.028 mmol/l per year, respectively), while there was no significant increase among urban populations. The results of National Nutrition Surveys are consistent with these findings and show that meat consumption per day per capita increased from 23.9 to 66.2 g in rural populations and 51.2 to 77.6 g in urban populations in the 1966 and 1990 surveys. It is suggested that different trends in coronary heart disease mortality should also be apparent in rural and urban populations over this period.

The associations between alcohol drinking and dietary habits and blood pressure in Japanese men

Objective: To clarify the relationships between blood pressure and alcohol, nutrients and electrolytes intakes in Japanese men. Design and method: A dietary survey was conducted in a rural population of Japan by the 2-day dietary record method, and blood pressure was measured with a standard sphygmomanometer. Blood pressure levels, nutrients and electrolytes intakes were compared among the non-drinkers and the tertiles of the alcohol-drinking subjects. The relationships between blood pressure and nutrients, electrolytes and alcohol intakes were also determined by multiple regression analysis. Results: Age and systolic blood pressure (SBP) were positively, and percentage of energy from fat and carbohydrates was negatively, related to the drinking categories. Univariate analysis showed that SBP was significantly related to age, body mass index (BMI) and alcohol intake, and diastolic blood pressure (DBP) was also significantly related to age, BMI and alcohol intake. Both SBP and DBP had a significant inverse relationship with the percentage of energy from fat (P<0.01). Both SBP and DBP were significantly related to drinking categories when the effects of age, BMI and percentage energy from fat intake on blood pressure were adjusted for (P<0.001). Multiple regression analysis revealed SBP to be significantly and positively associated with age, BMI and alcohol intake, and negatively associated with potassium intake, whereas DBP was significantly and positively associated with BMI and total energy intake, and was negatively associated with potassium and the percentage of energy intake from fat and carbohydrates. Conclusion: The positive association between alcohol drinking and blood pressure persisted even after consideration of the effects of age, BMI and other macronutrient and electrolytes intakes. The reduction of alcohol intake should be an important public health strategy in the primary prevention of hypertension in this population.

Theoretical and experimental aspects of the tri‐angle choice bag test of odor

Many problems caused by unpleasant odors from industries in Japan have not been solved in spite of the passage of the Japan Odor Control Act in 1977. This Act was made up as the limitation of the concentration of only eight odorants individually, and the evaluation of odor based on the concentration of each odorant is very different from that based on the sensory measure of residents in the damaged districts. From this point of view, many local self‐governments, such as Tokyo metropolis, Saitama and Kanagawa prefectures, are achieving steady results due to the enactment of regulations for odor control based on the sensory evaluation of odor by a method called tri‐angle choice bag test.1 However, the conventional sensory odor tests have some important unsolved problems, such as complicated procedure of sample preparation, treatment of accidental correct answers in the procedure of tri‐angle choice test, standardization to the odorless point for the panel and making the personal fluctuations of measured val...