[Evaluation of the relationship between household economic situation and food group intake in children attending nursery school]

Objectives　The relationship between household income and dietary intake among older children and adults in Japan has been studied. However, few studies have examined the relationship in younger children, and we believe that this should be taken into consideration from early childhood to correct health disparities. In this study, we examined the relationship between family income and dietary food group intake, and investigated the adequacy of food intake based on the Japanese Food Guide Spinning Top for young children aged 3 to 6 years attending nursery school. The goal of this study was to obtain trends in food intake that can be used to improve poor dietary intake of young children caused by socioeconomic factors.Methods　A dietary survey using the food weighing or recording method and a self-administered questionnaire on dietary status were conducted on two non-consecutive days, including weekdays and weekends, from October to December 2019 or 2020. The participants were 761 young children (423 boys and 338 girls) attending nursery schools in seven cities in Japan. Equivalent income was calculated from household income and the number of family members indicated in the dietary status survey. Intake of each food group and consistency with the Japanese Food Guide Spinning Top were compared in five quintiles.Results　Compared to the low equivalent income group, the high equivalent income group showed a decreasing trend in cereal intake and an increasing trend in the intake of sugar and sweeteners, green and yellow vegetables, and dairy products. The percentage of the low-income group who did not meet the definition of adequate intake using the Japanese Food Guide Spinning Top was lower for meals that include cereals and grain products, and higher for meals that include meat and fish, vegetable, milk and dairy products, and fruits.Conclusion　The lower income group had higher intake of cereals and lower intake of vegetables and fruits compared to the higher income group. This finding is similar to the results of studies in adults and older children. However, based on the Japanese Food Guide Spinning Top, >90% of young children have a diet that fall below the adequate intake of meals, including vegetable dishes and even on weekdays, which suggests a general vegetable deficiency in young children. Multifaceted support is required to address this concern, including measures to correct disparities of income and to ensure desirable nutrient intake in early childhood.

[Development of a new method for assessing the availability of low-sodium foods in Japan]

Objectives　Food environment improvement involving salt reduction requires improving access to and labeling low-sodium foods. Assessing the implementation status of these measures is also necessary. However, to date, no established methods exist for assessing the availability of low-sodium foods in communities. In this study, we aimed to devise a survey on the availability of low-sodium foods as a community food environment assessment method in order to establish common assessment methods, criteria, and practical measures, as well as standardization nationwide.Methods　A preliminary survey on the availability of low-sodium foods was conducted in Kitakyushu City in four stores with nationwide representation. Consent for providing information on handled product lists was obtained. The on-site lists collected through direct investigation by surveyors were compared with the handled product lists provided by the stores and analyzed to identify survey challenges and examine feasibility and the potential for accuracy. The definition of low-sodium foods, which emerged as a challenge in the preliminary survey, was confirmed. Preliminary survey data were carefully reviewed to establish classification criteria for low-sodium foods and create a low-sodium food list to serve as a reference for on-site surveys. Forms for recording the results of on-site surveys and a survey manual were developed. Registered dietitians conducted on-site surveys using the manual to confirm its applicability.Results　The preliminary survey results revealed that the on-site lists had fewer omissions and greater feasibility than store-provided lists. After clearly defining low-sodium foods, we established classification criteria (three major categories, seven subcategories, and 37 minor categories) considering the ease of on-site investigations and purchases. Three forms for recording survey results were developed, including a standard input form allowing detailed documentation of the availability of individual low-sodium foods, an aggregation form for a quantitative assessment of low-sodium foods availability, and a display form visualizing the availability of low-sodium foods by store. Furthermore, a survey manual was developed explaining the purpose and approach of the low-sodium foods availability survey, definition and classification criteria for low-sodium foods, and the three forms for recording survey results. Findings indicated that all registered dietitians could conduct on-site surveys using the manual and successfully collect and organize data.Conclusion　On-site surveys using the manual and documentation forms enabled easy and accurate assessments of low-sodium foods availability. Thus, this standardized method to assess the availability of low-sodium foods could be a food environment assessment method for regional salt reduction initiatives.

Mortality from major causes and lifestyles by proportions of public assistance recipients among 47 prefectures in Japan: Ecological panel data analysis from 1999 to 2016

Objective

Comprehensive investigations of correlations between subnational socioeconomic factors and trends in mortality and lifestyle are important for addressing public health problems.

Methods

Forty-seven prefectures in Japan were divided into quartiles based on the proportion of public assistance recipients (PPAR). Age-standardized mortality from all causes, cancer, heart disease, and stroke in each prefecture were averaged for these quartiles in 2000, 2005, 2010, and 2015. Data from the National Health and Nutrition Survey were obtained for the following periods: 1999-2001, 2003-2005, 2007-2009, 2012, and 2016. Body mass index (BMI), intake of total energy, vegetable and salt, step count, and prevalence of current smoking and drinking for individuals aged 40-69 years age range were standardized for each prefecture and averaged by quartile. A two-way analysis of variance was used to assess differences in mortality and lifestyle across different years or periods, and quartiles.

Results

Mortality rates decreased, with the first (lowest) quartile showing the lowest rates, across all causes, cancer and heart diseases in both sexes. BMI exhibited an increase in men, whereas, BMI in women and other lifestyle factors in both sexes, excluding smoking and drinking in women, exhibited a decrease. BMI, vegetable and salt intake, total energy intake in men, and smoking in women varied across quartiles. Lower quartiles exhibited lower BMI and smoking prevalence but higher energy, vegetables, and salt intake.

Conclusions

PPAR exhibited favorable trends and significant differences in mortality related to all causes, cancer and heart disease across both sexes, along with BMI among women.

Association of Pro-Inflammatory Diet with Long-Term Risk of All-Cause and Cardiovascular Disease Mortality: NIPPON DATA80

AIM

A pro-inflammatory diet may increase the risk of cardiovascular disease (CVD) and all-cause mortality. However, this remains inconclusive as there is yet no study using a dietary record method that has been conducted in a large general population. Furthermore, an underestimation of the pro-inflammatory diet may exist due to the unmeasured effect of salt intake. Thus, in this study, we aimed to examine how pro-inflammatory diet is associated with the long-term risk of all-cause and CVD mortality in a representative Japanese population.

METHODS

A national nutrition survey was conducted throughout Japan in 1980. After considering the exclusion criteria, 9284 individuals (56% women aged 30-92 years) were included in this study. In total, 20 dietary parameters derived from 3-day weighed dietary records were used to calculate the dietary inflammatory index (DII). The causes of death were monitored until 2009. The Cox proportional hazards model was used to determine multivariable-adjusted hazard ratios (HRs). Stratified analysis according to salt intake level was also performed.

RESULTS

Compared with the lowest quartile of DII, multivariable-adjusted HRs (95% confidence intervals) in the highest quartile were 1.28 (1.15, 1.41), 1.35 (1.14, 1.60), 1.48 (1.15, 1.92), 1.62 (1.11, 2.38), and 1.34 (1.03, 1.75) for all-cause mortality, CVD mortality, atherosclerotic CVD mortality, coronary heart disease mortality, and stroke mortality, respectively. Stratified analysis revealed stronger associations among individuals with higher salt intake.

CONCLUSIONS

As per our findings, a pro-inflammatory diet was determined to be positively associated with the long-term risk of all-cause and CVD mortality in a representative Japanese population. Thus, considering both salt intake and pro-inflammatory diet is deemed crucial for a comprehensive assessment of CVD risk.

Trends in mortality from major causes and lifestyle factors by per capita prefectural income: Ecological panel data analysis from 1995 to 2016 in Japan

In Japan, trends in mortality and lifestyle have not been fully investigated according to subnational socioeconomic factors. Forty-seven prefectures (subnational units) were divided into quartiles by annual per capita prefectural income. Age-standardized mortality from all causes, cancer, heart disease, and stroke was averaged by quartile in 1995, 2000, 2005, 2010, and 2015. Data from the National Health and Nutrition Survey were obtained for periods 1 (1995-1997), 2 (1999-2001), 3 (2003-2005), 4 (2007-2009), 5 (2012), and 6 (2016). Body mass index (BMI), the intake of vegetables and salt, the number of steps, and the prevalence of current smoking and drinking for the 40-69-year age range were standardized by 10-year age groups in the 2010 Japanese population and were averaged by quartile. Differences in mortality and lifestyle by year and period, and quartile were tested using a two-way analysis of variance. Mortality decreased in both sexes and mortality in men from all causes, cancer, and stroke differed by quartile, with mortality highest in the first (lowest) quartile. BMI in men and smoking prevalence in women increased, whereas remaining lifestyle factors except for the prevalence of drinking decreased in women. BMI and the number of steps in both sexes and current smoking prevalence in women differed by quartile, with lower quartiles showing a higher BMI and fewer step counts. In conclusion, favorable trends and significant differences in mortality from all causes, cancer, and stroke in men and BMI in women were observed by per capita prefectural income level.

Small High-Density Lipoprotein and Omega-3 Fatty Acid Intake Differentiates Japanese and Japanese-Americans: The INTERLIPID Study

AIM

To identify the most differentiated serum lipids, especially concerning particle size and fractions, between Japanese living in Japan and Japanese-Americans in Hawaii, in the absence of possible genetic confounders, and cross-sectionally examine the associated modifiable lifestyle factors.

METHODS

Overall, 1,241 (aged 40-59 years) Japanese living in Japan and Japanese-Americans in Hawaii were included. We quantified 130 serum lipid profiles (VLDL 1-5, IDL, LDL 1-6, high-density lipoprotein [HDL] 1-4, and their subfractions) using Bruker's 1H-nuclear magnetic resonance spectrometer for the primary outcome. Modifiable lifestyle factors included body mass index (BMI), physical activity, alcohol and smoking habits, and 70 nutrient parameters. We evaluated the different lipids between the groups using partial least squares-discriminant analysis and association between extracted lipids and lifestyle factors using multivariable linear regression analysis.

RESULTS

Concentrations of HDL4, HDL with the smallest particle size, were lower in Japanese than in Japanese-Americans of both sexes. Higher fish-derived omega-3 fatty acid intake and lower alcohol intake were associated with lower HDL4 concentrations. A 1% higher kcal intake of total omega-3 fatty acids was associated with a 9.8-mg/dL lower HDL4. Fish-derived docosapentaenoic acid, eicosapentaenoic acid, and docosahexaenoic acid intake were inversely associated with HDL4 concentration. There was no relationship between country, sex, age, or BMI.

CONCLUSIONS

Japanese and Japanese-Americans can be differentiated based on HDL4 concentration. High fish intake among the Japanese may contribute to their lower HDL4 concentration. Thus, HDL particle size may be an important clinical marker for coronary artery diseases or a fish consumption biomarker.

Individual Learning Needs of Japanese Public Health Dietitians by Years of Experience in Health Promotion

Lifelong education for dietitians in Japan is based mainly on competencies according to years of experience. Because learning content differs depending on the desired position and specialty, training programs that reflect the individual learning needs of public health dietitians are needed. This study aimed to assess the individual learning needs of public health dietitians via years of experience in health promotion. In 2021, an online survey of public health dietitians involved in health promotion in prefectures, designated cities, and other municipalities throughout Japan was conducted. Years of experience in health promotion were categorized as early (<10 years), mid-career (10-19 years), and leadership (≥20 years) periods. To ascertain individual learning needs, the survey asked about respondents' desired final position, career path, and skills they felt they needed to improve in the future. Of the 1649 public health dietitians analyzed, all administrative categories preferred to work as public health generalists in mid-career or leadership periods rather than in the early period. In municipalities, more public health dietitians across all experience categories selected "professional competence", such as knowledge in specialized areas and nutritional guidance techniques. It was suggested that public health dietitians in the mid-career and leadership periods have individual learning needs, in both nutrition specialists and public health generalists.

The vision for public health dietitians' skill improvement over the next 10 years in Japan: A qualitative study

Objectives

To obtain the basis for developing a new human resource development program. We examined the association between their position type and their vision for skill improvement in the profession in the next 10 years.

Study design

This was a qualitative study.

Methods

In 2021, we conducted an exhaustive survey of Japanese public health dietitians working in Japanese local governments. Using qualitative content analysis, we analyzed the participants' descriptions of how the profession could improve their skills over the next 10 years.

Results

Regardless of the participants' organization of employment or their target position type, seven common categories were extracted; [goals], [health promotion activities], [organizational activities], [evaluation from others], [cooperation], [skills to be acquired], and [means for improving skills]. Depending on the organization type, 35-40 subcategories were extracted from those who wanted to be staff, 35-38 subcategories from those who wanted to be supervisors, and 20-37 subcategories from those who wanted to be managers. Different subcategories were extracted to describe the difference between specialists and generalists in [goals]. Participants described challenges with [evaluation from others] and [collaboration], regardless of the target position type or [goals].

Conclusion

The vision for Japanese public health dietitians' skill improvement to achieve in the next 10 years describes challenges with business evaluation and collaborative work. However, participants differed across what skills they wanted to improve based on the direction of their careers. To offer public health dietitians learning content that connects with their desired direction, a new human resource development program needs to be considered.

Foods and Nutrients at Risk for Insufficient Intake by Community-Dwelling Healthy Older Women Eating Alone and Together in Japan-A Preliminary Finding

Eating alone and poor dental status have been reported to influence dietary intake in older adults. First, we compared nutrient and food intake and dental markers between women eating alone and together, who participated in a home health management program conducted by Kanazawa Medical University. The results showed the significantly higher intake of fresh fruit and some micro-nutrients and a lower decayed, missing, and filled teeth (DMFT) index (better dental status) in women eating alone after adjusting for age, suggesting that dental status may mediate the association between commensality and dietary intake. Then, we investigated nutrients and foods at risk for insufficient intake and associated with increasing dental markers. The risks for the insufficient intake of protein and n-3 and n-6 polyunsaturated fatty acids (PUFAs) were significantly increased with an increasing DMFT index. The risk for n-3 PUFA intake also increased with increasing numbers of missing teeth in women. Foods at risk for insufficient consumption included beans for women with an increasing DMFT index and green and yellow vegetables, fresh fruits, and meat and fish for women with increasing numbers of missing teeth. These findings suggest that good health management, including the treatment of decayed teeth, is important for the prevention of malnutrition in community-dwelling healthy older women.

Circulating plasma phospholipid fatty acid levels as a biomarker of habitual dietary fat intake: The INTERMAP/INTERLIPID Study

BACKGROUND

Accurate assessment of fat intake is essential to examine relationships between diet and disease risk. However, estimating individual intakes of fat quantity by dietary assessment is difficult.

OBJECTIVE

We assessed the association of plasma phospholipid fatty acid levels with dietary intake of fatty acids in the INTERMAP/INTERLIPID study, conducted with a standardized protocol.

METHODS

The study participants were 1339 men and women ages 40-59 years from five Japanese populations one from Hawaii; four from Japan. Fatty acid intake was estimated from four standardized 24-hour dietary recalls. Plasma phospholipid fatty acid composition was analyzed by gas chromatography. We illustrated the relationship between intake and circulating fatty acid levels using Spearman's rank-correlation coefficients, mean, and median values.

RESULTS

Spearman's rank-correlation coefficients between intake (g/d) and circulating fatty acid levels (µg/ml) were -0.03 to 0.21 for saturated fatty acids and monounsaturated fatty acids and -0.04 to 0.32 for trans fatty acids. The coefficients for essential n-3 and n-6 fatty acids were moderate to high, especially for eicosapentaenoic acid (EPA), 0.60; docosahexaenoic acid (DHA), 0.41; and EPA+DHA, 0.51. The circulating levels and intake of marine-derived n-3 fatty acids showed a linear association, at least for the intake of EPA+DHA up to 2.1 g/d.

CONCLUSION

We observed high correlation between intake and circulating levels of marine-derived n-3 fatty acids in participants from Japanese and Japanese-American populations with high and low fish intake. Plasma phospholipid marine-derived n-3 fatty acid measurements are a simple and reliable biomarker for assessing dietary intake.

Reduction of Cardiovascular Events and Related Healthcare Expenditures through Achieving Population-Level Targets of Dietary Salt Intake in Japan: A Simulation Model Based on the National Health and Nutrition Survey

Reducing population dietary salt intake is expected to help prevent cardiovascular disease and thus constrain increasing national healthcare expenditures in Japan’s super-aged society. We aimed to estimate the impact of achieving global and national salt-reduction targets (8, <6, and <5 grams/day) on cardiovascular events and national healthcare spending in Japan. Using published data including mean salt intake and systolic blood pressure from the 2019 National Health and Nutrition Survey, we developed a Markov model of a closed cohort of adults aged 40−79 years in 2019 (n = 66,955,000) transitioning among six health states based on the disease course of ischemic heart disease (IHD) and stroke. If mean salt intake were to remain at 2019 levels over 10 years, cumulative incident cases in the cohort would be approximately 2.0 million for IHD and 2.6 million for stroke, costing USD 61.6 billion for IHD and USD 104.6 billion for stroke. Compared with the status quo, reducing mean salt intake towards the targets over 10 years would avert 1−3% of IHD and stroke events and save up to 2% of related national healthcare costs. Attaining dietary salt-reduction goals among adults would yield moderate health economic benefits in Japan.

Trends in Prevalence, Treatment, and Control of Hypertension According to 40-Year-Old Life Expectancy at Prefectures in Japan from the National Health and Nutrition Surveys

The prevalence of hypertension has been decreasing in Japan due to improved medical treatment and a decrease in dietary salt intake. However, disparities in the prevalence, treatment, and control of hypertension are expected to occur in different regions. This study aimed to investigate the trends in the prevalence, treatment, and control of hypertension at the prefectural level of life expectancy among Japanese population. We used data from the National Health and Nutrition Survey and analysed the individual survey information of individuals aged 40–69 years by dividing it into six terms, i.e., 1995–1997, 1999–2001, 2003–2005, 2007–2009, 2012, and 2016. Prefectures were classified into four groups according to their 40-year-old life expectancy in 2000. Outcome values were standardised to the population by 10-year age groups in 2010, and they were tested by two-way analysis of variance according to six terms and life expectancies. The prevalence of hypertension tended to decrease, especially among women, whereas the treatment and control tended to improve from the first to the sixth period in both men and women. The prevalence and treatment of hypertension in men with longer life expectancy tended to be lower than that in other groups, and there was no obvious difference in the control. In women, there were no obvious differences in the prevalence, treatment, or control. Reducing the prevalence of hypertension by improving lifestyle factors, such as high salt intake in each prefecture with a relatively short life expectancy, may be important to resolve the disparity in life expectancy among prefectures.

Investigation of the urinary sodium-to-potassium ratio target level based on the recommended dietary intake goals for the Japanese population: The INTERMAP Japan

Growing epidemiological evidence has shown an association of the urinary sodium (Na) to potassium (K) ratio (Na/K ratio) with blood pressure and cardiovascular diseases. However, no clear cutoff level has been defined. We investigated the cutoff level of the urinary Na/K ratio under different dietary guidelines for Japanese individuals, especially that endorsed by the 2020 revised Japanese Dietary Reference Intakes (DRIs). A population of 1145 Japanese men and women aged 40 to 59 years from the INTERMAP study was examined. Using high-quality standardized data, the averages of two 24 h urinary collections and four 24 h dietary recalls were used to calculate the 24 h urinary and dietary Na/K ratios, respectively. Associations between the urinary and dietary Na/K ratios were tested by sex- and age-adjusted partial correlation. The optimal urinary Na/K ratio cutoff level was determined by receiver operating characteristic (ROC) curves and sex-specific cross tables for recommended dietary K and salt. Overall, the average molar ratio of 24 h urinary Na/K was 4.3. We found moderate correlations (P < 0.001) of the 24 h urinary Na/K ratio with 24 h urinary Na and K excretion (r = 0.52, r = -0.49, respectively) and the dietary Na/K ratio (r = 0.53). ROC curves showed that a 24 h urinary Na/K ratio of approximately 2 predicted Na and K intake that meets the dietary goals of the Japanese DRIs. The range of urinary Na/K ratios meeting the dietary goals of the Japanese DRIs for both Na and K was 1.6‒2.2 for men and 1.7‒1.9 for women. Accomplishing a urinary Na/K ratio of 2 would be desirable to achieve the DRIs dietary goals for both Na and K simultaneously in middle-aged Japanese men and women accustomed to Japanese dietary habits. This observational study is registered at www.clinicaltrials.gov as NCT00005271.

[Use of simulation models in health economic evaluation studies of dietary salt-reduction policies for cardiovascular disease prevention]

Objectives　Social security costs related to the healthcare and long-term care of patients with cardiovascular diseases is a national burden that is expected to grow as Japan's population ages. Nutritional policies for improving the nation's diet could prevent cardiovascular diseases, but scientific evidence on their costs and outcomes is limited. This study gives an overview of health economic evaluation studies on population-wide dietary salt-reduction policies that have been instituted for the purposes of cardiovascular disease prevention. Thus, this study provides background information for the development of evaluation methods that can be utilized in Japan for analyzing the effects of nutritional policies on public health and social security cost containment.Methods　We extracted representative health economic simulation models that are used for predicting the effects of cardiovascular disease-related interventions: Cardiovascular Disease Policy Model, IMPACT Coronary Heart Disease Policy and Prevention Model, US IMPACT Food Policy Model, Assessing Cost-Effectiveness (ACE) approach to priority-setting, and Prevention Impacts Simulation Model (PRISM). Next, we collected original articles on studies that used these models for assessing the costs and effects of national population-wide dietary salt-reduction policies. We then outlined the background, structure, and applied studies associated with each model.Results　The five models utilized Markov cohort simulation, microsimulation, proportional multistate life tables, and system dynamics to predict the effect of dietary salt-reduction policies on blood pressure reduction and cardiovascular disease prevention. The models were applied to countries such as Australia, England, and the United States to simulate long-term (10 years to lifetime) costs and effects. These applied studies examined policies that included health promotion campaigns, sodium labels on the front of food packages, and mandatory or voluntary reformulation by the food industry to reduce the salt content of processed foods.Conclusion　Health economic simulation modeling is actively being used to evaluate scientific evidence on the costs and outcomes of national dietary salt-reduction policies. Similarly, leveraging simulation modeling techniques could facilitate the evaluation and planning of dietary salt-reduction policies and other nutritional policies in Japan.

Frequency of consumption of balanced meals, bodyweight gain and incident risk of glucose intolerance in Japanese men and women: A cohort study

AIMS/INTRODUCTION

This cohort study assessed the risk for bodyweight gain and development of glucose intolerance based on the frequency of consumption of balanced meals including grain, fish or meat and vegetables.

MATERIALS AND METHODS

The participants (8,573 men, 3,327 women) were employees of a company in Japan. A self-administered questionnaire was used to evaluate the frequency of balanced meal consumption. Bodyweight changes and the incidence of glucose intolerance (glycated hemoglobin >6.0%) during the 3-year follow-up period were determined through annual health examinations.

RESULTS

The mean bodyweight change over a period of 3 years was 0.78 kg for men and 0.84 kg for women. A lower frequency of balanced meals was associated with a higher bodyweight gain for men (P for trend = 0.004), but not for women. During the study, 464 men and 115 women developed glucose intolerance. Overall, the frequency of balanced meals was not associated with the risk of glucose intolerance in either sex. However, the interaction between the frequency of balanced meals and degree of obesity had a significant effect on the incidence of glucose intolerance in men (P = 0.005), with less frequent consumption of balanced meals being associated with a higher risk for glucose intolerance among men with a BMI ≥25.0 kg/m2 (P for trend = 0.007).

CONCLUSIONS

A higher frequency of balanced meals, including grain, fish or meat and vegetable dishes - important components of healthy Japanese food - was associated with a lower risk of glucose intolerance in obese men, but not in non-obese men and women.

Relationships of Alcohol Consumption with Coronary Risk Factors and Macro- and Micro-Nutrient Intake in Japanese People: The INTERLIPID Study

Several studies have reported a J-shaped relationship between alcohol consumption and coronary heart disease (CHD) risk. However, the mechanisms of this relationship remain unclear. This study aimed to evaluate the relationships of alcohol consumption with established CHD risk factors and with macro-/micro-nutrient intake among Japanese people. Participants were 1,090 Japanese men and women aged 40-59 y enrolled in the INTERLIPID study, excluding former drinkers. Based on two 7-d alcohol records, participants were classified as non-drinkers (0 g/wk), light-drinkers (<100 g/wk), moderate-drinkers (100-299 g/wk), or heavy-drinkers (≥300 g/wk). Detailed macro-/micro-nutrient intake was evaluated using four in-depth 24-h dietary recalls and adjusted for total energy intake excluding alcohol. We analyzed the associations of CHD risk factors and nutrient intake with alcohol consumption. Serum high-density lipoprotein cholesterol and blood pressure were higher and low-density lipoprotein cholesterol was lower among those with higher alcohol consumption. J-shaped relationships with alcohol consumption were observed for the proportion of current smokers, number of cigarettes smoked, and prevalence of hypertension; these risk factors were lowest among light-drinkers. Carbohydrate and total fiber intakes were lower and protein and dietary cholesterol intakes were higher among those with higher alcohol consumption. These associations were similar for men and women. Alcohol consumption was related to nutrient intake as well as established CHD risk factors. Non-drinkers were higher on some CHD risk factors than were light-drinkers. These findings may influence the J-shaped relationship between alcohol consumption and CHD risk.

Food Sources of Dietary Potassium in the Adult Japanese Population: The International Study of Macro-/Micronutrients and Blood Pressure (INTERMAP)

A lower-than-recommended potassium intake is a well-established risk factor for increased blood pressure. Although the Japanese diet is associated with higher sodium intake and lower potassium intake, few studies have examined the source foods quantitatively. Studies on dietary patterns in association with potassium intake will be useful to provide dietary advice to increase potassium intake. Twenty-four-hour (hr) dietary recall data and 24-hr urinary potassium excretion data from Japanese participants (574 men and 571 women) in the International Study of Macro/Micronutrients and Blood Pressure (INTERMAP) were used to calculate food sources of potassium and compare food consumption patterns among quartiles of participants categorized according to 24-hr urinary potassium excretion per unit of body weight (UK/BW). The average potassium intake was 2791 mg/day per participant, and the major sources were vegetables and fruits (1262 mg/day), fish (333 mg/day), coffee and tea (206 mg/day), and milk and dairy products (200 mg/day). Participants in the higher UK/BW quartile consumed significantly more vegetables and fruits, fish, and milk and dairy products, and ate less rice and noodles. Conclusion: Advice to increase the intake of vegetables and fruits, fish, and milk may be useful to increase potassium intake in Japan.

P6234The relationship of alcohol consumption with risk factors of coronary heart disease and the intake of macro- and micro-nutrients in Japanese: the INTERLIPID study

Background

Many studies have reported the J-shaped relationship between alcohol consumption and coronary heart disease (CHD) risk; therefore, light-drinkers is generally recognized to be associated with the lower risk of CHD. However, the mechanisms of lower risk for CHD in light-drinkers are still unclear. Alcohol drinking status is likely to be associated with not only CHD risk factors but also dietary intake. Nevertheless, few studies report these relationships in detail.

Purpose

The purpose of this study is to evaluate the relationships of alcohol drinking status with CHD classical risk factors and the intake of macro- and micro- nutrients in Japanese.

Methods

Study participants were 1,090 Japanese men and women aged 40–59 years from The INTERLIPID study excepted for 55 individuals who had missing data (n=26) and were past-drinkers (n=29). Alcohol consumption was assessed with two 7-day alcohol records, and average ethanol intake (per week) was calculated. Participants were classified into following 4 groups: non-drinkers (0g/week), light-drinkers (<100 g/week), moderate-drinkers (100–299 g/week), and heavy-drinkers (≥300 g/week). Serum LDL and HDL cholesterol, blood pressure (BP), the prevalence of hypertension and dyslipidemia, and smoking status were assessed as CHD risk factors. The intake of energy and macro- and micro-nutrients were evaluated from the four-timed in-depth 24-hr dietary recalls. Nutrient intake densities were calculated per total energy intake without alcohol. The analysis of variance and chi-squared test were used to evaluate the relations of alcohol status with CHD risk factors and nutrient intake.

Results

Serum HDL cholesterol levels increased and LDL cholesterol levels decreased with increasing alcohol consumption. Systolic and diastolic BP increased with increasing alcohol consumption. J-shaped relationships with alcohol consumption were observed for the proportion of current smoker, number of cigarettes, and the prevalence of hypertension; that is, light-drinkers was lowest among all groups. The prevalence of dyslipidemia was the highest in non-drinkers, and decreased with increasing alcohol consumption. In heavy-drinkers, total energy (kcal/day) was the highest, but energy intake without alcohol (kcal/day) was the lowest. For macronutrients, the intake of carbohydrate (%kcal) decreased, and the intakes of total and animal protein (%kcal) increased with increasing alcohol consumption. The intakes of total cholesterol (mg/1000kcal) and sodium (mg/1000kcal) increased, and total fiber (g/1000kcal) decreased with increasing alcohol consumption. These associations were similar in men and women.

Conclusions

Alcohol consumption was related with not only CHD classical risk factors but also the intake of macro- and micro-nutrients. Non-drinkers had a higher proportion of some CHD risk factors than light-drinkers. These results might influence on J-shaped relationship between alcohol consumption and CHD risk.

Acknowledgement/Funding

1: Ministry of Education, Science, Sports, and Culture of Japan, 2: National Institutes of Health, Bethesda, MD, USA

Overall nutrient and total fat intake among Japanese people: The INTERLIPID Study Japan

BACKGROUND AND OBJECTIVES

Total fat intake is linked to the intake of other nutrients. Little data are available on the extent to which total fat affects diet quality in Japanese people. We investigated the relationship between total fat intake and other nutrient intake using INTERLIPID/ INTERMAP data on Japanese people living in Japan.

METHODS AND STUDY DESIGN

The participants included 371 men and 401 women with a healthy body mass index and between the ages of 40 and 59 from 4 population samples in Japan. Nutrient intake data were based on four in-depth 24-hour dietary recalls per person.

RESULTS

Analysis of covariance adjusted for age revealed that total fat intake was positively related to intakes of calcium, thiamine, riboflavin, meat, eggs, and milks and dairy products for both sexes. Total fat intake was inversely associated with carbohydrate and cereals intake for both sexes. On average, men with total fat intake between 25.0 and 27.4% of total energy had saturated fatty acids above 7%, which is the upper limit recommended for preventing lifestyle-related diseases. Men with total fat intake less than 20% of total energy had a higher risk of not meeting the Dietary Reference Intakes for Japanese (2015) for some nutrients.

CONCLUSIONS

Total fat intake was positively associated with calcium, thiamine, and riboflavin intakes and inversely associated with carbohydrate intake. Our results suggest that in 40-59-year-old men with a healthy body mass index, total fat intake between 20 and 27% of total energy may best support adequate intake of other nutrients.

Cardiovascular Risk Assessment Chart by Dietary Factors in Japan - NIPPON DATA80

BACKGROUND

Many studies show that dietary factors such as vegetables, fruit, and salt are associated with cardiovascular disease (CVD) risk. However, a risk assessment chart for CVD mortality according to combinations of dietary factors has not been established.Methods and Results:Participants were 9,115 men and women aged 30-79 years enrolled in the National Nutritional Survey of Japan in 1980 with a 29-year follow-up. Dietary intake was assessed using a 3-day weighed dietary record at baseline. Cox regression models were used to estimate the hazard ratio (HR) of CVD mortality stratified by vegetables, fruit, fish, and salt consumption. HRs of CVD mortality according to combinations of dietary factors were color coded on an assessment chart. Higher intakes of vegetables, fruit, and fish, and lower salt intake were associated with lower CVD mortality risk. HRs calculated from combinations of dietary factors were displayed using 5 colors corresponding to the magnitude of the HR. People with the lowest intake of vegetables, fruit, and fish, and higher salt intake had a HR of 2.87 compared with those with the highest intake of vegetables, fruit, and fish, and lower salt intake.

CONCLUSIONS

Vegetables, fruit, fish, and salt intake were independently associated with CVD mortality risk. The assessment chart generated could be used in Japan as an educational tool for CVD prevention.

Seasonal changes in sleep duration and sleep problems: A prospective study in Japanese community residents

Background

A scientific understanding of the effects of seasonal changes on sleep duration and sleep problems such as insomnia and hypersomnia has yet to be elucidated; however, such an understanding could aid the establishment of an optimal sleep hygiene program to treat such problems.

Methods

We investigated the effects of seasonal changes on sleep duration and sleep problems in Japanese community residents. Data on 1,388 individuals aged 15–89 years who participated in the Survey of Seasonal Variations in Food Intakes conducted by the National Institute of Health and Nutrition of Japan (2004–2007) were analyzed. Participants completed a questionnaire including items on sleep duration and sleep problems (difficulty initiating sleep [DIS], difficulty maintaining sleep [DMS]/early morning awakening [EMA], and excessive daytime sleepiness [EDS]). Data were prospectively collected at four time points (spring, summer, fall, and winter).

Results

Seasonal changes in sleep duration were found, with the longest in winter and the shortest in summer (winter–summer difference: 0.19 h). The seasonality of sleep duration was influenced by age, sex, and residential area. In terms of age, seasonal changes in sleep duration were found in the middle and old age groups, but not in the young age group. Seasonal changes in the frequencies of sleep problems were found for some items in the young age group (DMS/EMA and EDS) and middle age group (DIS and DMS/EMA); however, no such changes were observed in the old age group.

Conclusion

Seasonal effects on sleep and sleep problems were found in Japanese community residents, but these varied between age groups. Furthermore, seasonal changes in sleep duration were influenced by sex and residential area.

The Relationship of Dietary Cholesterol with Serum Low-Density Lipoprotein Cholesterol and Confounding by Reverse Causality: The INTERLIPID Study

Aim: The positive relationship between dietary cholesterol and serum cholesterol has been questioned by a set of recent cohort studies. This study aimed to investigate how employment status and education years relate to the association between dietary cholesterol and serum low-density lipoprotein cholesterol (LDL-C) in a Japanese population.

Methods: A population-based, random sample, cross-sectional study (INTERLIPID) was performed. Among 1,145 Japanese individuals aged 40–59 years, 106 were excluded because of special diets, use of lipid-lowering drugs, hormone replacement, and missing data, leaving 1,039 individuals (533 men and 506 women). Dietary cholesterol was assessed from four 24-h dietary recalls, and LDL-C was measured enzymatically with an autoanalyzer. A standard questionnaire inquired about employment status and education years.

Results: In men, a 1 standard deviation (SD) higher dietary cholesterol was associated with 3.16 mg/dL lower serum LDL-C (P = 0.009; unadjusted model). After adjustment for covariates, higher serum LDL-C was estimated per 1 SD higher intake of dietary cholesterol in nonemployed men [self-employed, homemakers, farmers, fishermen, and retired employees; β = +9.08, 95% confidence interval (CI) = +0.90–+17.27] and less educated men (β = +4.46, 95% CI = −0.97–+9.90), whereas an inverse association was observed in employed men (β = −3.02, 95% CI= −5.49–−0.54) and more educated men (β = −3.66, 95% CI = −6.25–−1.07).

Conclusions: In men who were nonemployed and less educated, a higher intake of dietary cholesterol was associated with elevated concentrations of serum LDL-C, whereas an inverse association was observed in men who were employed and more educated.

Vegetable Protein Intake was Inversely Associated with Cardiovascular Mortality in a 15-Year Follow-Up Study of the General Japanese Population

AIM

To examine the relationship between the intake of dietary vegetable protein and CVD mortality in a 15-year follow-up study of a representative sample of the Japanese population.

METHODS

A total of 7,744 participants aged 30 years or older (3,224 males and 4,520 females) who were free of CVD at baseline were included in this analysis. Vegetable protein intake (% energy) was assessed using a three-day semi-weighed dietary record at baseline. Multivariable-adjusted hazard ratios (HRs) were calculated using Cox's proportional hazards model after adjusting for confounding factors.

RESULTS

The total person-years studied were 107,988 with a mean follow-up period of 13.9 years. There were 1,213 deaths during the follow-up period, among which 354 (29.2%) were due to CVD. Vegetable protein intake was associated inversely with CVD and cerebral hemorrhage mortality, with the HRs for a 1% energy increment in vegetable protein intake being 0.86 (95% CI, 0.75-0.99) and 0.58 (95% CI, 0.35-0.95), respectively. In the subgroup analysis of participants with or without hypertension, the inverse association between vegetable protein intake and CVD mortality was more evident in the nonhypertensive group, with the HRs for CVD and stroke being 0.68 (95% CI, 0.50-0.94) and 0.50 (95% CI, 0.30-0.84), respectively.

CONCLUSIONS

Vegetable protein intake may prevent future CVD, particularly in nonhypertensive subjects in the Japanese population. However, further studies are necessary to examine the biological mechanisms of this effect.

Having few remaining teeth is associated with a low nutrient intake and low serum albumin levels in middle-aged and older Japanese individuals: findings from the NIPPON DATA2010

Background

Oral health is thought to be associated with diet quality, and socioeconomic status (SES) affects both oral health and diet. The aim of this study was to investigate the association between the number of teeth and dietary intake as well as nutritional biomarker, considering the subjects’ SES.

Methods

We conducted a cross-sectional analysis of data from 2049 individuals aged ≥ 50 years from the National Integrated Project for Prospective Observation of Non-communicable Disease and its Trends in the Aged 2010. The number of remaining teeth was categorized into age-specific quartiles (Q1 to Q4). We assessed the adjusted means and 95% confidence intervals for dietary variables by the number of teeth using analysis of covariance. Stratified analyses by SES were also conducted.

Results

The intake of grain products was 31 g higher, and those of vegetables and meat were 30 g and 8 g lower, respectively, in Q1 (fewer teeth) than in Q4 (more teeth). Carbohydrate intake was higher whereas protein, minerals (potassium, magnesium, and zinc), vitamins (vitamins A, E, B₁, B₆, β-carotene, and folic acid), and dietary fiber intakes were lower among individuals with fewer teeth. Adjusted mean serum albumin levels were low in Q1. The associations between the number of teeth and dietary intake were more evident in individuals with a low SES.

Conclusions

Having few remaining teeth was associated with a low nutrient intake and low serum albumin levels in middle-aged and older Japanese adults, and these associations were more evident in individuals with low SES.

Electronic supplementary material

The online version of this article (10.1186/s12199-018-0752-x) contains supplementary material, which is available to authorized users.

Associations of High-Density Lipoprotein Particle and High-Density Lipoprotein Cholesterol With Alcohol Intake, Smoking, and Body Mass Index - The INTERLIPID Study

BACKGROUND

Recently, high-density lipoprotein particles (HDL-P) have been found to be more strongly inversely associated with coronary artery disease (CAD) risk than their counterpart, HDL cholesterol (HDL-C). Given that lifestyle is among the first targets in CAD prevention, we compared the associations of HDL-P and HDL-C with selected lifestyle factors. Methods and Results: We examined 789 Japanese participants of the INTERLIPID Study: men (n=386) and women (n=403) aged 40-59 years in 1996-1998. Participants treated for dyslipidemias were excluded. Lifestyle factors included alcohol intake, smoking amount, and body mass index (BMI). Multivariable linear regression was used for cross-sectional analyses of these factors with HDL-P, HDL-C, HDL-P size subclasses (small, medium and large) and mean HDL-P size. In men, higher alcohol intake was associated with higher HDL-P and higher HDL-C. The associations of alcohol, however, were strongest with HDL-P. A higher smoking amount tended to be associated with lower HDL-P and HDL-C. In contrast, BMI was not associated with HDL-P, but was strongly inversely associated with HDL-C. While alcohol intake favored larger mean HDL-P size, smoking and BMI favored a lipid profile with smaller HDL-P subclasses and overall smaller mean HDL-P size. Similar, but generally weaker results were observed in women.

CONCLUSIONS

Although both HDL-P and HDL-C are parameters of HDL, they have different associations with alcohol, smoking and BMI.

The Influence of the Japanese Nationwide Cardiovascular Prevention System Health Guidance on Smoking Cessation Among Smokers: A Propensity Score Matching Analysis

Aim: We investigated whether 2 types of personalized health guidance (repeated and single counseling) in the Japanese nationwide cardiovascular prevention system promoted smoking cessation among smokers.

Methods: The study included 47,745 Japanese smokers aged 40 to 74 years classified into 2 personalized health guidance schemes. After a 1-year follow-up, we compared the rates of smoking cessation between individuals who had received counseling (“supported”) and those who had not received counseling (“unsupported”). Using propensity score matching analysis, we estimated the average treatment effect (ATE) of each approach on smoking cessation after balancing out the characteristics between the supported and unsupported groups. The propensity score regression model included age, medical insurance type, weight gain since the age of 20 years, exercise, eating habits, alcohol intake, quality of sleep, readiness to modify lifestyle, willingness to receive support, and body mass index.

Results: In the repeated counseling scheme, the age-adjusted rates of smoking cessation in the supported and unsupported groups were 8.8% and 6.3% for males, and 9.8% and 9.1% for females respectively. In the single counseling scheme, the corresponding rates were 8.4% and 7.3% for supported and unsupported males, and 11.0% and 11.7% for supported and unsupported females respectively. The ATE of repeated counseling was + 2.64% (95% confidence interval: + 1.51% to + 3.77%) for males and + 3.11% (−1.85% to +8.07%) for females. The ATE of single counseling was +0.61% (−1.17% to +2.38%) for males and −1.06% (−5.96% to +3.85%) for females.

Conclusions: In the Japanese cardiovascular prevention system, repeated counseling may promote smoking cessation among male smokers.

Effectiveness of a Self-monitoring Device for Urinary Sodium-to-Potassium Ratio on Dietary Improvement in Free-Living Adults: a Randomized Controlled Trial

BACKGROUND

Reducing the urinary sodium-to-potassium ratio is important for reducing both blood pressure and risk of cardiovascular disease. Among free-living Japanese individuals, we carried out a randomized trial to clarify the effect of lifestyle modification for lowering urinary sodium-to-potassium ratio using a self-monitoring device.

METHODS

This was an open, prospective, parallel randomized, controlled trial. Ninety-two individuals were recruited from Japanese volunteers. Participants were randomly allocated into intervention and control groups. A month-long dietary intervention on self-monitoring urinary sodium-to-potassium ratio was carried out using monitors (HEU-001F, OMRON Healthcare Co., Ltd., Kyoto, Japan). All participants had brief dietary education and received a leaflet as usual care. Monitors were handed out to the intervention group, but not to the control group. The intervention group was asked to measure at least one spot urine sodium-to-potassium ratio daily, and advised to lower their sodium-to-potassium ratio toward the target of less than 1. Outcomes included changes in 24-hour urinary sodium-to-potassium ratio, sodium excretion, potassium excretion, blood pressure, and body weight in both groups.

RESULTS

Mean measurement frequency of monitoring was 2.8 times/day during the intervention. Changes in urinary sodium-to-potassium ratio were -0.55 in the intervention group and -0.06 in the control group (P = 0.088); respective sodium excretion changes were -18.5 mmol/24 hours and -8.7 mmol/24 hours (P = 0.528); and corresponding potassium excretion was 2.6 mmol/24 hours and -1.5 mmol/24 hours (P = 0.300). No significant reductions were observed in either blood pressure or body weight after the intervention.

CONCLUSIONS

Providing the device to self-monitor a sodium-to-potassium ratio did not achieve the targeted reduction of the ratio in "pure self-management" settings, indicating further needs to study an effective method to enhance the synergetic effect of dietary programs and self-monitoring practice to achieve the reduction. However, we cannot deny the possibility of reducing sodium-to-potassium ratio using a self-monitoring device.

Differences in Lifestyle Improvements With the Intention to Prevent Cardiovascular Diseases by Socioeconomic Status in a Representative Japanese Population: NIPPON DATA2010

BACKGROUND

The relationships among socioeconomic status and lifestyle improvements have not yet been examined in a representative Japanese population.

METHODS

We analyzed data from 2,647 participants (1,087 men and 1,560 women) who participated in NIPPON DATA2010. This survey inquired about lifestyle improvements and socioeconomic status. Education was categorized as low (≤9 years), middle (10-12 years), and high (≥13 years). Marital status was categorized as married, divorced, widowed, and never married/other. A multivariable logistic regression model was used to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) of lifestyle improvements with the intention of preventing cardiovascular diseases for educational attainment and marital status, with adjustments for age and awareness of cardiovascular disease risk factors.

RESULTS

Overall, 1,507 (56.9%) participants practiced prevention and improvements in hypertension, diabetes, elevated cholesterol, and metabolic syndrome, and the OR of lifestyle improvements was significantly higher with a high education than with a low education in men (OR 2.86; 95% CI, 1.96-4.17) and women (OR 2.36; 95% CI, 1.67-3.33). The number of participants who practiced prevention and improvements in hypertension, diabetes, elevated cholesterol, and metabolic syndrome was significantly lower in divorced than in married men (OR 0.46; 95% CI, 0.22-0.95) and women (OR 0.53; 95% CI, 0.33-0.86).

CONCLUSIONS

Specific differences caused by educational attainment and marital status may exist in lifestyle improvements.

Relationship Between Socioeconomic Status and the Prevalence of Underweight, Overweight or Obesity in a General Japanese Population: NIPPON DATA2010

BACKGROUND

Socioeconomic status (SES) imbalances in developed and developing countries may result in individuals being overweight and obese. However, few studies have investigated this issue in Japan. We herein examined the relationship between SES and being underweight, overweight or obese according to sex and age groups (20-64 or ≥65 years) in Japan.

METHODS

In 2010, we established a cohort of participants in the National Health and Nutrition Survey of Japan. We divided 2,491 participants (1,081 men and 1,410 women) according to the WHO definitions of underweight, overweight or obesity and performed multinomial logistic analyses using BMI <18.5 kg/m2 (underweight), BMI 25.0-29.9 kg/m2 (overweight), and BMI ≥30.0 kg/m2 (obese) versus BMI 18.5-24.9 kg/m2 (normal) as the outcome, with SES groups as the main explanatory variables.

RESULTS

In adult men, a lower education level relative to a higher education level was inversely associated with obesity after adjustments for other SESs (odds ratio [OR] 0.41; 95% confidence interval [CI], 0.18-0.96). However, in adult women, lower education level was positively associated with being overweight and obese (OR 1.67; 95% CI, 1.07-2.49 for overweight and OR 2.66; 95% CI, 1.01-7.01 for obese). In adult women, a lower household income was positively associated with being overweight and obese (obese: OR 4.84; 95% CI, 1.36-17.18 for those with a household income <2 million JPY relative to those with ≥6 million JPY).

CONCLUSIONS

In adult women, a lower education level and lower household income were positively associated with being overweight or obese. In contrast, in adult men, a lower education level was inversely associated with obesity. Gender and age differences in SESs affect the prevalence of being overweight or obese.

Relationships among Food Group Intakes, Household Expenditure, and Education Attainment in a General Japanese Population: NIPPON DATA2010

BACKGROUND

A lower socioeconomic status (SES) may be related to the intake of unhealthy food; however, this relationship has not been examined in detail. This study was undertaken to examine relationships among food group intakes and SES in a representative Japanese population.

METHODS

This was a cross-sectional study using the baseline data of NIPPON DATA2010, which is a prospective cohort study of the National Health and Nutrition Survey in Japan. A total of 2,898 participants were included in the baseline survey in 2010. The effects of age (<65 years and ≥65 years), equivalent household expenditure (EHE), and education attainment on food group intakes (gram per 1,000 kcal) were analyzed using a two-way analysis of variance.

RESULTS

When EHE was lower, cereal intake was higher in men and women. Among men, fish, milk, and alcohol intakes were reduced with lower EHE. Among women, vegetable intake was reduced with lower EHE. In men and women, cereal intake was higher with lower education attainment. In contrast, meat intake was reduced with lower education attainment.

CONCLUSIONS

Lower SES was associated with a higher cereal intake and lower vegetable, fish, meat, and milk intakes in a representative Japanese population. Socioeconomic discrepancies need to be considered in order to promote healthier dietary habits.

Macronutrient Intake and Socioeconomic Status: NIPPON DATA2010

BACKGROUND

This study examined the relationships among household income, other SES indicators, and macronutrient intake in a cross-sectional study of a representative Japanese population.

METHODS

In 2010, we established a cohort of participants in the National Health and Nutrition Survey (NHNS) from 300 randomly selected areas throughout Japan. A total of 2,637 participants (1,145 men and 1,492 women) were included in the study. Data from NHNS2010 and the Comprehensive Survey of Living Conditions 2010 (CSCL2010) were merged, and relationships among macronutrient intake and SES were evaluated. Additionally, socioeconomic factors associated with a risk of a higher carbohydrate/lower fat intake beyond dietary recommendations were evaluated.

RESULTS

Household income was positively associated with fat intake (P = 0.001 for men and <0.001 for women) and inversely associated with carbohydrate intake (P = 0.003 for men and <0.001 for women) after adjustments for age and other SES variables. Similar relationships were observed between equivalent household expenditure (EHE) and macronutrient intake; however, these relationships were weaker than those of household income. Older age was the factor most strongly associated with a high carbohydrate/low fat intake, followed by household income, EHE, education levels, and occupation type.

CONCLUSIONS

Older age was the factor most strongly associated with a high carbohydrate/low fat intake, and some aspects of SES, such as household income, EHE, education levels, and occupation type, were independently associated with an imbalanced macronutrient intake. SES may affect the health status of individuals through the intake of macronutrients.

Associations of self-efficacy, social support, and knowledge with fruit and vegetable consumption in Japanese workers

BACKGROUND AND OBJECTIVES

Previous studies have suggested that self-efficacy, social support, and knowledge are primary psychosocial predictors of dietary behavior in adults. The present study aimed to investigate the associations of self-efficacy, social support, and knowledge with fruit and vegetable consumption in Japanese workers.

METHODS AND STUDY DESIGN

From September to November 2014, a self-administered questionnaire was completed by Japanese workers at 8 workplaces in Niigata, Japan. Self-efficacy and social support for fruit and vegetable consumption were measured using a 3-item Likert scale across particular situations. Knowledge was measured using a single item about the recommended guidelines for fruit and vegetable consumption in Japan. Fruit and vegetable consumption was assessed using a validated, brief-type self-administered diet history questionnaire.

RESULTS

Of the 457 respondents, 395 participants' data were analyzed. Scores in self-efficacy and social support showed a significant and positive association with fruit (p<0.001, p=0.002) and vegetable consumption (p=0.001, p=0.015). Knowledge was significantly and positively associated with vegetable consumption (p=0.015) but did not statistically differ in fruit consumption (p=0.645).

CONCLUSIONS

The findings of this study suggest that selfefficacy and social support are positively associated with fruit and vegetable consumption in Japanese workers.

Relationship of Consumption of Meals Including Grain, Fish and Meat, and Vegetable Dishes to the Prevention of Nutrient Deficiency: The INTERMAP Toyama Study

A Japanese-style diet consists of meals that include grain (shushoku), fish and meat (shusai), and vegetable dishes (fukusai). Little is known about the association of such meals (designated well-balanced meals hereafter) with nutrient intake. We therefore examined the frequency of well-balanced meals required to prevent nutrient deficiency. Participants were Japanese people, ages 40 to 59 y, from Toyama, recruited for INTERMAP, in an international population-based study. Each person provided 4 in-depth 24-h dietary recalls (149 men, 150 women). The prevalence of risk ratios of not meeting the Dietary Reference Intakes for Japanese (2015) was calculated. Well-balanced diets were assessed by the Japanese Food Guide Spinning Top. We counted the frequencies of meals in which participants consumed 1.0 or more servings of all 3 dishes categories. We divided the frequency of consumption of well-balanced meals into the following 4 groups: <1.00 time/d, 1.00-1.49 times/d, 1.50-1.74 times/d, and ≥1.75 times/d. Compared with participants in the highest frequency group for well-balanced meals, those who consumed well-balanced meals less than once a day had a higher risk of not meeting the adequate intake for potassium and the recommended dietary allowance for vitamin A. Those who consumed well-balanced meals on average less than 1.50 times per day had a higher risk of not meeting the recommended dietary allowance for calcium and vitamin C. Our results suggest that individuals should on average consume well-balanced meals more than 1.5 times per day to prevent calcium and vitamin C deficiencies.

Skipping breakfast and 5-year changes in body mass index and waist circumference in Japanese men and women

OBJECTIVE

This study investigated the relationship between frequency of skipping breakfast and annual changes in body mass index (BMI) and waist circumference (WC).

METHODS

The participants were 4,430 factory employees. BMI and WC were measured repeatedly at annual medical examinations over a 5-year period. The association between frequency of skipping breakfast at the baseline examination and annual changes in anthropometric indices was evaluated using the generalized estimating equation method.

RESULTS

The mean (standard deviation) BMI was 23.3 (3.0) kg m^-2 for men and 21.9 (3.6) kg m^-2 for women; and the mean WC was 82.6 (8.7) cm for men and 77.8 (9.8) cm for women. During the follow-up period, mean BMI increased by 0.2 kg m^-2 for men and women, and mean WC increased by 1.1 cm for men and 1.0 cm for women. The annual change in the BMI of men who skipped breakfast four to six times per week was 0.061 kg m^-2 higher, and that of those who skipped breakfast seven times per week was 0.046 kg m^-2 higher, compared with those who did not skip breakfast. Annual changes in the WC of male participants who skipped breakfast seven times per week was 0.248 cm higher than that of those who did not skip breakfast. Skipping breakfast was not associated with changes in BMI or WC in women.

CONCLUSIONS

Skipping breakfast was closely associated with annual changes in BMI and WC among men, and eating breakfast more than four times per week may prevent the excessive body weight gain associated with skipping breakfast.

Dietary tofu intake and long-term risk of death from stroke in a general population

BACKGROUND & AIM

Although dietary soy intake is linked with health benefits, a relation with stroke has not been established. The present study examined the association between the intake of tofu, the richest source of dietary soy, with stroke mortality in a general population cohort of Japanese men and women.

METHODS

Data comprise 9244 Japanese enrolled in the National Nutrition Survey of Japan in 1980. Participants were free of cardiovascular disease and followed for 24 years. Dietary intake was estimated from 3-day weighed food records. Multivariable Cox regression models were used to estimate hazard ratios across levels of tofu intake.

RESULTS

During follow-up, there were 417 deaths due to stroke (88 cerebral hemorrhage [CH], 245 cerebral infarction [CI], and 84 of other subtypes). Among all men, and in women aged 65 years or more, tofu intake was unrelated to each form of stroke. For young women (<65 years of age), a significantly lower risk of CH in the top versus bottom quartile of tofu intake was observed (Multivariable-adjusted HR = 0.26, 95% CI: 0.08-0.85).

CONCLUSIONS

In this large prospective study with long follow-up of Japanese men and women, consumption of tofu was unrelated to the risk of stroke except for CH in women <65 years of age. Whether the association in younger women is real or due to chance alone warrants further study.

Dietary sodium-to-potassium ratio as a risk factor for stroke, cardiovascular disease and all-cause mortality in Japan: the NIPPON DATA80 cohort study

OBJECTIVES

To evaluate the impact of dietary sodium and potassium (Na-K) ratio on mortality from total and subtypes of stroke, cardiovascular disease (CVD) and all causes, using 24-year follow-up data of a representative sample of the Japanese population.

SETTING

Prospective cohort study.

PARTICIPANTS

In the 1980 National Cardiovascular Survey, participants were followed for 24 years (NIPPON DATA80, National Integrated Project for Prospective Observation of Non-communicable Disease And its Trends in the Aged). Men and women aged 30-79 years without hypertensive treatment, history of stroke or acute myocardial infarction (n=8283) were divided into quintiles according to dietary Na-K ratio assessed by a 3-day weighing dietary record at baseline. Age-adjusted and multivariable-adjusted HRs were calculated using the Mantel-Haenszel method and Cox proportional hazards model.

PRIMARY OUTCOME MEASURES

Mortality from total and subtypes of stroke, CVD and all causes.

RESULTS

A total of 1938 deaths from all causes were observed over 176 926 person-years. Na-K ratio was significantly and non-linearly related to mortality from all stroke (p=0.002), CVD (p=0.005) and total mortality (p=0.001). For stroke subtypes, mortality from haemorrhagic stroke was positively related to Na-K ratio (p=0.024). Similar relationships were observed for men and women. The observed relationships remained significant after adjustment for other risk factors. Quadratic non-linear multivariable-adjusted HRs (95% CI) in the highest quintile versus the lowest quintile of Na-K ratio were 1.42 (1.07 to 1.90) for ischaemic stroke, 1.57 (1.05 to 2.34) for haemorrhagic stroke, 1.43 (1.17 to 1.76) for all stroke, 1.39 (1.20 to 1.61) for CVD and 1.16 (1.06 to 1.27) for all-cause mortality.

CONCLUSIONS

Dietary Na-K ratio assessed by a 3-day weighing dietary record was a significant risk factor for mortality from haemorrhagic stroke, all stroke, CVD and all causes among a Japanese population.

Validity of a food frequency questionnaire in a population with high alcohol consumption in Japan

BACKGROUND AND OBJECTIVES

Alcohol consumption has a relatively large impact on energy intake in drinkers, and several studies reported different dietary habits from non-drinkers. However, few studies have investigated the influence of alcohol consumption on the validity of the Food Frequency Questionnaire (FFQ). To investigate its influence, we conducted a validity test in a population with high alcohol consumption.

METHODS AND STUDY DESIGN

The study subjects were 66 residents living on an island in the south-western part of Japan. We conducted the FFQ and 12-day-weighed dietary records (12d-WDRs) in each 3 day of each 4 season. We calculated Pearson correlation coefficients (CCs) and agreement rates according to quartile classification after adjusting for energy.

RESULTS

The intake energy (kcal) estimated from 12d-WDRs and FFQ was 1,641 and 1,534 in women, and 2,093 and 1,979 in men, respectively. The cumulative percentage contribution of the alcohol energy was 6.7% in men. De-attenuated, log-transformed Pearson's median CCs between the nutrients quantified with the 12d-WDRs and FFQ were 0.51 in women and 0.38 in men. The CCs for carbohydrate and saturated fatty acids intake of men were lower than those in the previous Tokai study using the same FFQ. The findings in agreement rates were consistent with the Tokai study.

CONCLUSION

This study suggested that the FFQ can be used for epidemiological studies using categorical comparisons in this population, although the underestimation of carbohydrates and other nutrients in the FFQ should be taken into consideration.

Food sources of dietary sodium in the Japanese adult population: the international study of macro-/micronutrients and blood pressure (INTERMAP)

PURPOSE

It is often reported that Na intake levels are higher in Japan than in western countries. Detailed analysis of food intake and its association with Na intake are necessary for supporting further decreases in Na consumption in Japan. We investigated the association between Na and food intake by food group using data from the Japanese participants of the INTERMAP Study.

METHOD

Results from the Japanese participants of the INTERMAP Study who did not use antihypertensive medication and/or consume a reduced Na diet were used (531 men and 518 women, aged 40-59 years), obtained from four 24-h dietary recalls and two 24-h urine collections from each participant. We developed a classification system with 46 food group classifications; food consumption and Na intake from these groups were compared across quartiles of participants determined by 24-h urinary Na excretion per unit of body weight (UNa/BW).

RESULTS

Average daily Na intake from Japanese high-Na foods was 2552 mg/day. Participants with a higher UNa/BW consumed a significantly greater amount of high-Na Japanese foods, such as salted fish (P = 0.001) and miso soup (P < 0.001). They also had greater amount of rice (P = 0.001). Participants with lower UNa/BW consumed a significantly greater amount of western foods, such as bread (P < 0.001) and milk and dairy products (P < 0.001).

CONCLUSIONS

Detailed analyses of various Japanese and western food intakes in addition to Na intake were performed. These results can be used to help draw up effective programs for the reduction in Na intake and prevention of prehypertension/hypertension in the Japanese population.

Selection of a Dietary Assessment Method in Accordance with an Objective and Evaluation of the Results

In recent years, many studies have used epidemiological techniques to investigate the relationships of daily energy and nutrition intake to food intake, and to disease onset and treatment or prevention. Therefore, dietary assessments are now being used in various situations. A range of dietary assessment methods exists, and each has advantages and disadvantages. However, there is no absolute and universally applicable dietary assessment method. The most appropriate method or a combination of methods must be selected in accordance with factors such as the objective of a study and the number of subjects. Moreover, it is necessary to interpret dietary assessment results multilaterally and to grasp dietary habits, elements of a daily lifestyle environment, and physical conditions that could influence the diet.

Dietary carbohydrate intake, presence of obesity and the incident risk of type 2 diabetes in Japanese men

Aims/Introduction

The present cohort study assessed the risk among Japanese men for developing type 2 diabetes, based on the percentage of energy intake from carbohydrates and degree of obesity.

Participants and Methods

The participants were 2,006 male factory employees, and the macronutrient intake of each patient was measured using a self‐administered diet history questionnaire. The incidence of diabetes was determined in annual blood examinations over a 10‐year period.

Results

During the study, 232 participants developed diabetes. The crude incidence rates (/1,000 person‐years) for different levels of carbohydrate intake as a percentage of calories consumed (<50.0, 50.0–57.4, 57.5–65.0, >65.0% of energy intake) were 16.5, 14.4, 12.7 and 17.6. Overall, carbohydrate intake was not associated with the risk of diabetes. However, there was significant interaction between carbohydrate intake and degree of obesity on the incidence of diabetes (P for interaction = 0.024). Higher carbohydrate intake was associated with elevated risk for diabetes among participants with a body mass index ≥25.0 kg/m² (P for trend = 0.034). For obese participants, the multivariate‐adjusted hazard ratio for those with carbohydrate intakes >65% energy was 2.01 (95% confidence interval 1.08–3.71), which was significantly higher than that of participants with carbohydrate intakes 50.0–57.4% energy.

Conclusions

Higher carbohydrate intake was associated with higher risk of diabetes in obese participants, but not in non‐obese participants. Obese participants with carbohydrate intakes >65% energy should reduce their intakes to levels within the desirable carbohydrate energy proportion for Japanese (50–65% energy) to prevent development of type 2 diabetes.

[Associations among physical condition, life hour, and dietary intake male Japanese shift workers: physical condition and lifestyle survey of male Japanese shift workers]

OBJECTIVES

The purpose of this study was to understand the actual state of life hours (working time, sleep time, and time of meal intake) and dietary habits of male shift work employees, and to elucidate the impact of working arrangements and dietary habits on their physical condition and health problems.

METHODS

The subjects were 187 male employees (aged 18-64 years) working for an industrial company in Toyama prefecture. We used a self-administered questionnaire to assess dietary habit, lifestyle habits, and life hours at the time of a periodic health examination in April 2013. The subjects were grouped based on their working condition (i.e., day shift, late shift, and late-night shift) into two groups of day shift (n = 107) and shiftwork (n = 80). The proportion of time spent sleeping and feeding was determined in half hour increments, and the incidences of skipping meals (breakfast, lunch and dinner) and midnight snack intake were calculated for each working condition. We also examined the association between the frequency of eating and physical condition for each working condition.

RESULTS

The state of life hours of the shiftwork group during the day was similar to that of the day shift group. However, the workers' state of life hours, incidences of skipping meals, and midnight snack intake varied considerably when working at the other shift times. In the shiftwork group, regardless of the working patterns, the BMI and % body fat of the group that ate more than three times a day were significantly lower than those of the group that ate less than twice a day.

CONCLUSIONS

The results of the present study suggest that it is difficult to ensure the time and opportunity for meals for shift workers. We consider that it is necessary to prevent them skipping of meals, and to support a proper dietary intake during the night.

Relationship of three different types of low-carbohydrate diet to cardiometabolic risk factors in a Japanese population: the INTERMAP/INTERLIPID Study

PURPOSE

Low-carbohydrate diets (LCD) are a popular dietary strategy for weight reduction. The effects of LCD on long-term outcome vary depending on type of LCD, possibly due to the fact that effects on cardiometabolic risk factors may vary with different types of LCD. Accordingly, we studied these relations.

METHODS

We assessed serum concentrations of high-density lipoprotein cholesterol (HDLc), low-density lipoprotein cholesterol (LDLc), high-sensitivity C-reactive protein (CRP), total cholesterol, glycated hemoglobin, and uric acid, and nutrient intakes by standardized methods in men and women ages 40-59 years from four population samples of Japanese in Japan (553 men and 544 women, combined). For people consuming usual, animal-based, and plant-based LCDs, we calculated LCD scores, based on relative level of fat, protein, and carbohydrate, by modifying the methods of Halton et al. Instead of calculating scores based on animal or vegetable fat, we used saturated fatty acids (SFA) or monounsaturated fatty acids (MUFA) + polyunsaturated fatty acids (PUFA).

RESULTS

In multivariate regression analyses with adjustment for site, age, sex, BMI, smoking, alcohol intake, physical activity, and years of education, all three LCD scores were significantly positively related to HDLc (all P < 0.001), but not to LDLc. The plant-based LCD score was significantly inversely related to log CRP (coefficient = -0.010, P = 0.018).

CONCLUSIONS

All three LCD scores were significantly positively related to HDLc. The plant-based LCD score was significantly inversely related to CRP. Carbohydrate intake below 50 % of total energy with higher intakes of vegetable protein and MUFA + PUFA, and lower intakes of SFA may be favorable for reducing cardiometabolic risk factors.

[Effects of a long-term intervention in a work cafeteria on employee vegetable intake]

OBJECTIVES

We examined the effects on employee vegetable intake of a long-term intervention in an employee work cafeteria.

METHODS

The subjects were approximately 1,200 employees (aged 19-61 years) of an industrial company in Fukui prefecture. We promoted the intake of typical Japanese style meals that combined three elements (staple foods, main dishes and vegetable dishes) to increase vegetables intake. We displayed all items on the menus of the employee cafeteria using three colors (yellow, red and green to denote three elements) to indicate healthy food choices for the maintenance of a healthy food environment. We advised employees to choose meals containing the three elements at the time of payment, for nutritional education (appropriate portion choice: APC). We evaluated the ratio of APC at the same time. To calculate the mean daily intake per person, we carried out a questionnaire survey similar to the "semi-quantitative food frequency questionnaire" and asked about the frequency and approximate intake of vegetables.

RESULTS

The APC was 63.5% after one year of intervention, significantly increased to 82.1% after two years (p < 0.001), and was 80.0% after three years of intervention (p < 0.001). Vegetable intake at breakfast (p < 0.001), lunch (p < 0.001) and dinner (p = 0.011), and from vegetable juice (p = 0.030) significantly increased after three years of intervention. The consumption of pickles significantly decreased after three years of intervention (p = 0.009). It was estimated that the vegetable intake of men increased from 167.3 to 184.6 g, and that of women from 157.9 to 187.7 g.

CONCLUSIONS

Employee estimated vegetable intake was significantly increased and that of pickles was significantly decreased by a long-term intervention (three years) in the employee work cafeteria.