Global Associations of the Traditional Japanese Diet Score with Hypertension Prevalence and Systolic Blood Pressure from 2009 to 2019: A Cross-Sectional and Longitudinal Ecological Study.

OBJECTIVE: Prevention and improvement of hypertension is one of the most important health issues worldwide. The traditional Japanese diet contributes to the prevention of some non-communicable diseases associated with hypertension. However, whether traditional Japanese dietary patterns are associated with hypertension prevalence and systolic blood pressure (SBP) worldwide remains unknown. In this study, we aimed to investigate whether the traditional Japanese diet score (TJDS) is associated with hypertension prevalence and SBP. METHODS: This cross-sectional and longitudinal ecological study from 2009 to 2019 included 141 countries with a population of at least 1 million. All data used for analysis were obtained from internationally available databases. The TJDS was calculated using country-specific supplies of five foods commonly eaten in the traditional Japanese diet (rice, fish, soybean, vegetables, and egg) and three less commonly eaten foods (wheat, milk, and red meat). Hypertension was defined by SBP ≥140 mmHg, diastolic blood pressure ≥90 mmHg, or use of antihypertensive medications. The mean SBP was >25 age-standardized data. A general linear model was used for the cross-sectional model in 2009, and a linear mixed model was used for the longitudinal analysis from 2009 to 2019. The covariates included gross domestic product, percentage of population aged >65 years, years of education, smoking rate, average body mass index, physical activity, and energy supply. RESULTS: The TJDS was negatively associated with hypertension prevalence (ß ± standard error: -0.861 ± 0.202, p < 0.001) and SBP (ß ± standard error: -0.364 ± 0.154, p < 0.05) in the cross-sectional analysis. The TJDS was significantly negatively associated with hypertension prevalence (ß ± standard error: -0.845 ± 0.200, p < 0.001) and SBP (ß ± standard error: -0.312 ± 0.149, p < 0.05) in the 10-year longitudinal analysis controlled for full covariables. CONCLUSIONS: Traditional Japanese dietary patterns are associated with lower hypertension prevalence and SBP worldwide.

Traditional japanese diet score and the sustainable development goals by a global comparative ecological study.

BACKGROUND: Reducing the environmental impact of the food supply is important for achieving Sustainable Development Goals (SDGs) worldwide. Previously, we developed the Traditional Japanese Diet Score (TJDS) and reported in a global ecological study that the Japanese diet is associated with reducing obesity and extending healthy life expectancy etc. We then examined the relationship between the TJDS and environmental indicators. METHODS: The average food (g/day/capita) and energy supplies (kcal/day/capita) by country were obtained from the Food and Agriculture Organization of the United Nations Statistics Division database. The TJDS was calculated from eight food groups (beneficial food components in the Japanese diet: rice, fish, soybeans, vegetables, and eggs; food components that are relatively unused in the traditional Japanese diet: wheat, milk, and red meat) by country using tertiles, and calculated the total score from - 8 to 8, with higher scores meaning greater adherence to the TJDS. We used Land Use (m2), Greenhouse gas (GHG) emissions 2007/2013 (kg CO2eq), Acidifying emissions (g SO2eq), Eutrophying emissions (g PO43- eq), Freshwater (L), and water use (L) per food weight by Poore et al. as the environmental indicators and multiplied these indicators by each country's average food supply. We evaluated the cross-sectional and longitudinal associations between the TJDS and environmental indicators from 2010 to 2020. This study included 151 countries with populations ≥ 1 million. RESULTS: Land use (ß ± standard error; -0.623 ± 0.161, p < 0.001), GHG 2007 (-0.149 ± 0.057, p < 0.05), GHG 2013 (-0.183 ± 0.066, p < 0.01), Acidifying (-1.111 ± 0.369, p < 0.01), and Water use (-405.903 ± 101.416, p < 0.001) were negatively associated with TJDS, and Freshwater (45.116 ± 7.866, p < 0.001) was positively associated with TJDS after controlling for energy supply and latitude in 2010. In the longitudinal analysis, Land Use (ß ± standard error; -0.116 ± 0.027, p < 0.001), GHG 2007 (-0.040 ± 0.010, p < 0.001), GHG 2013 (-0.048 ± 0.011, p < 0.001), Acidifying (-0.280 ± 0.064, p < 0.001), Eutrophying (-0.132 ± 0.062, p < 0.05), and Water use (-118.246 ± 22.826, p < 0.001) were negatively associated with TJDS after controlling for confounders. CONCLUSIONS: This ecological study suggests that the traditional Japanese dietary pattern might improve SDGs except Fresh water.

Development of a Method for Estimating Dietary Salt Intake Using the Overnight Urinary Sodium/Potassium Ratio.

BACKGROUND: There are many patients who need to restrict and assess salt in their diet. However, it is difficult to estimate daily salt intake accurately and easily. Therefore, a method for estimating dietary salt intake using the overnight urinary sodium (Na)/potassium (K) ratio was developed. METHODS: The study involved 43 healthy adults (13 males, 30 females). From 2018 to 2020, subjects consumed a salt-adjusted diet for 11 - 30 days continuously, and overnight urine was collected daily. Using the previous day's salt intake as the objective variable, an equation for estimating the salt intake was developed using a general linear model. To verify the accuracy of the estimating equation, the estimated salt intake of the previous day was calculated using our equation and Tanaka's equation, which is an estimating equation from spot urine widely used in clinical practice and epidemiological studies to estimate dietary salt intake, and they were compared with the actual salt intake. RESULTS: The results of the analysis showed that model 1 (previous day's salt intake (g) = 3.62 + 0.64 × urinary Na/K ratio + 0.18 × conductivity (mS/cm) - 0.43 × sex (male 0, female 1)) was the optimal model. Then, salt intake was estimated using model 1 and Tanaka's equation, and compared with actual salt intake. The Pearson's product-moment correlation coefficient between the actual and estimated salt intake was r = 0.618 (P < 0.001) and r = 0.573 (P < 0.001) for model 1 estimates and Tanaka's equation estimates, respectively. The percentages of errors within ±30% from the actual salt intake were 64.2% and 58.4% for model 1 and Tanaka's equation, respectively. CONCLUSION: An equation for estimating salt intake was developed using the Na/K ratio and conductivity of overnight urine. Although the applicability of this method to hypertensive patients and the elderly has not been studied and needs to be clarified in the future, the estimating equation developed is simple and may be a useful method for daily monitoring of dietary salt intake.