Japanese Dietary Habits Research Articles

Japanese Dietary Habits and Their Impact on Health

In recent years, the impact of dietary patterns on human health has come under an increasing attention. A wealth of data suggests that healthy dietary patterns reduce the risk of diet-related diseases. Japan currently has the longest average life span in both sexes in the world. Japanese diet has always been known to be healthy, and its unique dietary habits are one of the key reasons for the longevity of the Japanese people. This study examines the relationship between certain non-communicable diseases' incidence and mortality and the Japanese diet. According to this study, in women, eating a lot of soy products is related to a reduction of breast cancer risk. however, relations between soy foods and prostate cancer in men is still debatable. Consumption of soy and fish is linked to a reduction in cardiovascular disease. The high-sodium diet in Japan is related to the increase of stroke and gastric cancer risks, while green tea and coffee are related to a lower risk of stroke. There are few studies that analyses the association between dietary patterns and related diseases in Japan, and this study provides ideas for analyzing the relationship between diet and health in Japan.

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.

Japanese-Style Diet and Cardiovascular Disease Mortality: A Systematic Review and Meta-Analysis of Prospective Cohort Studies.

This systematic review and meta-analysis elucidate the effects of the Japanese-style diet and characteristic Japanese foods on the mortality risk of cardiovascular disease (CVD), cerebrovascular disease (stroke), and heart disease (HD). This review article followed the PRISMA guidelines. A systematic search in PubMed, The Cochrane Library, JDreamIII, and ICHUSHI Web identified prospective cohort studies on Japanese people published till July 2020. The meta-analysis used a random-effects model, and heterogeneity and publication bias were evaluated with I2 statistic and Egger’s test, respectively. Based on inclusion criteria, we extracted 58 articles, including 9 on the Japanese-style diet (n = 469,190) and 49 (n = 2,668,238) on characteristic Japanese foods. With higher adherence to the Japanese-style diet, the pooled risk ratios (RRs) for CVD, stroke, heart disease/ischemic heart disease combined (HD/IHD) mortality were 0.83 (95% CI, 0.77–0.89, I2 = 58%, Egger’s test: p = 0.625, n = 9 studies), 0.80 (95% CI, 0.69–0.93, I2 = 66%, Egger’s test: p = 0.602, n = 6 studies), and 0.81 (95% CI, 0.75–0.88, I2 = 0%, Egger’s test: p = 0.544, n = 6 studies), respectively. Increased consumption of vegetables, fruits, fish, green tea, and milk and dairy products decreased the RR for CVD, stroke, or HD mortality. Increased salt consumption elevated the RR for CVD and stroke mortality. Increased consumption of dietary fiber and plant-derived protein decreased the RR for CVD, stroke, and HD/IHD mortality. The Japanese-style diet and characteristic Japanese foods may reduce CVD mortality. Most studies conducted diet surveys between 1980 and the 1990s. This meta-analysis used articles that evaluated the same cohort study by a different method. A new large-scale cohort study matching the current Japanese dietary habits is needed to confirm these findings.

Political Legitimisation and Identity Construction by Italian Courts Through the Journey of Four Japanese Princes, 1585

This article examines the relationship between the Japanese delegation sent by the Jesuit Valignano and rival courts in Italy, specifically Mantua and Venice, who competed to receive the four Christian princes of Japan. This case study underlines in particular the strong link between politics, religion and theatre. The Serenissima integrated the foreign delegation into its rites and ceremonies, going so far as to include its members in a theatrical performance. Mantua, thanks to its network of diplomats, later surpassed Venice with a splendid firework display and an interest in Japanese dietary habits. The letters written at the time testify that the Japanese were impressed, but this meeting was intercultural only by chance, as it served first and foremost the policy of prestige of each of the two courts.

Grading of Japanese Diet Intakes by 24-Hour Urine Analysis of Taurine and Soy Isoflavones in Relation to Cardiovascular Risks.

To investigate the association of the Japanese diet with risks for lifestyle-related diseases, the biomarkers of seafood and soybean consumption, taurine (T) and soy isoflavones (I), and others were analyzed in 24-hour urine (24U) samples collected from participants of the Cardiovascular Diseases and Alimentary Comparison (CARDIAC) Study coordinated by the World Health Organization (WHO). The data of T and I normalized for creatinine content in 24U were divided into five quintiles, T1 to T5, and I1 to I5. The total data of the collected samples were divided into 25 groups, which were obtained by 5 (T1-T5)×5 (I1-I5) according to 24U excretions of T and I corresponding to the intake of seafood and soybeans from the least to the highest, respectively. Since these two nutrients were often consumed together in the Japanese diet, this characteristic was expressed as J1 to J5 based on the amounts of 24UT and I excretions. The risks for lifestyle-related diseases, obesity (body mass index, BMI), and cholesterolemia became lower during the transition from J1 to J5, while HDL cholesterol levels became higher from J1 to J5. On the contrary, urinary salt excretion and the sodium (Na)/potassium (K) ratio became higher from J1 to J5. Systolic blood measure was significantly lower in J3 than in J5. Diastolic blood pressure was also significantly lower in J3 than in J1. In conclusion, the higher the J score, which corresponds to Japanese dietary habits, the lower the BMI and cholesterol levels, as well as mortality rate from coronary heart disease, but the higher the average life expectancy among the Japanese. However, these higher J scorings were associated with high-salt intake and high Na/K ratios; therefore, they contributed to high blood pressure and high mortality rate caused by stroke in Japan. These results indicate that low-salt intake should be recommended to the Japanese who are consuming seafood and soy regularly in order to maintain lower blood pressure and to extend healthy life expectancy with a lower risk of stroke. Moreover, high scorings of the Japanese diet correspond to the high intake of magnesium (Mg) which is rich in seafood including seaweeds and soy. Therefore, low-salt seafood and soy intake is expected to reduce the incidence of the metabolic syndrome, the risk of which is inversely related to T and Mg intake.

What is the scientific definition of the Japanese diet from the viewpoint of nutrition and health?

The Japanese people have enjoyed longevity for several decades, and Japanese dietary habits are considered to contribute to this longevity. The scientific definition of the Japanese diet, however, is not yet fully established. The Working Group 1 of the Healthy Diet Research Committee of the International Life Sciences Institute Japan reviewed the literature to collect definitions of the Japanese diet appearing in articles in the fields of diet, nutrition, foods, and human health. This report addresses the definitions and the questions raised by these definitions. Among 283 relevant articles identified, 116 were carefully screened and included in the analysis. In most of the articles, the authors self-defined the Japanese diet; some studies used a government-proposed definition. This review revealed no systematic approach to define the Japanese diet from the viewpoints of nutrition and health. Before conducting studies to determine whether the Japanese diet is healthy, it is important to address the question of what the Japanese diet is from the viewpoint of human nutrition rather than culinary culture.

Globalization of food and the crisis of the Japanese dietary habits

Globalization of food and the crisis of the Japanese dietary habits

Multifaceted Studies on Cooking Quality of Various Rice and Japanese Dietary Habits and Culture

Multifaceted Studies on Cooking Quality of Various Rice and Japanese Dietary Habits and Culture

The current status and issues of Japanese dietary habits: From the results of National Health and Nutrition Survey Japan

The current status and issues of Japanese dietary habits from the results of the National Health and Nutrition Survey Japan would be discussed. Total energy intake and protein intake of Japanese in the past 45 years showed a decreasing trend. On the other hand, fat intake increased, but carbohydrate intake decreased. According to the physical condition survey of the 2017 National Health and Nutrition Survey, the proportion of obese individual (BMI≧25 kg/m2) was higher for men in their 20s to 60s compared with the goal for Healthy Japan 21 (secondary), and the proportion for thinness (BMI<18.5 kg/m2) was higher for women in their 20s. In older people, physical working hours, protein intake and oral function were associated with trend in malnutrition. Salt intake has been decreasing during a decade, however further improvement should be needed. At present, prevention of lifestyle-related diseases in men in their 20s to 60s, prevention of young women’s thinness and elderly people’s frailty might be issues. In order to resolve these issues, utilization of a Japanese Food Guide, Smart-meal system and nutrient labeling on foods, maintenance of appropriate body weight, Shokuiku throughout individual’s life, utilization of Exercise and Active Guides, maintenance for oral health, etc. might be effective. These strategies might lead to the extension of the healthy life expectancy.

Japanese dietary habits: Results from a questionnaire survey on 305 health check-up participants

Japanese dietary habits: Results from a questionnaire survey on 305 health check-up participants

Association of lifestyle and body structure to ocular axial length in Japanese elementary school children

BackgroundThe purpose of this study is to determine whether the lifestyle and body stature are significantly associated with the axial length (AL) of the eyes of Japanese third grade students.MethodsA prospective, cross sectional, observational study was performed on 122 third grade students consisting of 61 boys and 61 girls ages 8 to 9 years. The AL, body height, body weight, and body mass index (BMI) were measured. The lifestyle was determined by activities such as the daily duration of indoor studying, television viewing, use of computers and smart phones, outdoor activity time, bed time, Japanese or Western dietary habits, and parental myopia were investigated by a questionnaire with three or five grade levels. The relationship between AL and the questionnaire variables were analyzed by Spearman’s correlation analyses.ResultsWesternized dietary habits (r = −0.24, P = 0.01), duration of computer and smart phone use (r = 0.24, P = 0.008), parental myopia (r = 0.39, P < 0.001), body weight (r = 0.26, P = 0.005), and BMI (r = 0.23, P = 0.011) were significantly correlated with the AL. Multiple logistic regression analyses showed that the sex [r = −0.48; 95% confidence interval (CI) -0.80 to −0.17, P = 0.003], body weight (r = 0.04; 95% CI 0.02 to 0.07, P = 0.038), westernized dietary habits (r = −0.30; 95% CI -0.55 to −0.05, P = 0.021), and parental myopia (r = 0.40; 95% CI 0.20 to 0.61, P < 0.001) were significantly and independently correlated with the AL.ConclusionsThe body weight and parental myopia and westernized dietary habits are factors significantly associated with myopia. Changing from Japanese food style to westernized food style might increase the risk of progression of school myopia.

Risk factors for renal cell carcinoma in a Japanese population.

The incidence of renal cell carcinoma (RCC) is high in Western and Northern Europe and North America, and low in Asia. Although the incidence of RCC in Japan is lower than the rates in the other industrialized countries, there is no doubt that it is increasing. In this paper, we would like to introduce the summary of findings of JACC study, which evaluate the risk factors for RCC in a Japanese population. JACC study suggests nine risk factors (i.e., smoking, obesity, low physical activity, hypertension, diabetes mellitus, kidney diseases, beef, fondness for fatty food and black tea) and one preventive factor (i.e., starchy roots such as taro, sweet potato and potato) in a Japanese population. In Japan, however, drinking black tea may be a surrogate for westernized dietary habits while eating starchy roots may be a surrogate for traditional Japanese dietary habits. Further studies may be needed to evaluate risk factors for RCC because the number of cases is small in our studies.

Globalization, localization and food culture: perceived roles of social and cultural capitals in healthy child feeding practices in Japan

The current study examined parental perceptions of sociocultural factors associated with healthy child feeding practices among parents of preschool-age children in rural Japan. Fifteen Japanese mothers of preschool-age children participated in this qualitative study. These participants were aged 22-39 years and resided in a rural town in western Japan. We conducted semi-structured qualitative interviews to assess parental perceptions of healthy child feeding practices and their relationships with globalization and localization. These interviews were transcribed, translated into English and coded, based on the principles of grounded theory. A codebook was developed and pre-identified, and the newly-identified themes from this codebook were examined and compared. Overall, local and seasonal foods, along with traditional Japanese foods and simple foods (soshoku), were considered to be beneficial for children. Participants also noted that children were expected to be mindful and exhibit good table manners that reflect cultural values related to meal-time socializing or family bonding, and food appreciation. On the other hand, the majority of the participants stated that foods containing food additives and imported foods were unsuitable for children. Participants noted that strong social capital, especially social support from their mothers or mothers-in-law, as well as social networks for obtaining fresh local foods, contributed to healthy child feeding practices. Cultural capital (including the preservation of traditional Japanese dietary habits, eating rules and inter-generational commensality), was also identified as being key to healthy feeding practices. Identifying and promoting the social and cultural capital that positively support healthy child feeding practices may be an important component of nutrition education programs.

Serum omega-3 fatty acids are not associated with age-related macular degeneration

Evaluation of: Kabasawa S, Mori K, Horie-Inoue K et al. Associations of cigarette smoking but not serum fatty acids with age-related macular degeneration in a Japanese population. Ophthalmology 118(6), 1082–1088 (2011).Age-related macular degeneration (AMD) is the leading cause of visual impairment in the elderly in developed countries. Risk factors for AMD are classified into endogenous nonmodifiable factors, including genetics and environmental factors such as smoking and dietary habits. Both epidemiological and experimental studies suggest that dietary omega-3 long-chain fatty acids would participate to prevent from the development of AMD. The mechanisms behind this association have been poorly defined until now. Kabasawa and coworkers recently published that Japanese AMD patients did not exhibit a different serum fatty acid profile compared with Japanese controls, although the circulating levels of omega-3 fatty acids were doubled in Japanese subjects when compared with subjects in the USA – a consequence of Japanese dietary habits privileging fish consumption.

Risk Factors for Renal Cell Cancer in a Japanese Population

The incidence of renal cell cancer has been increasing worldwide. Although the incidence of renal cell cancer in Japan is lower than the rates in the other industrialized countries, there is no doubt that it is increasing. In this paper, we would like to introduce the result of our studies, which evaluate the risk factors for renal cell cancer in Japan. Hypertension, diabetes mellitus, kidney diseases, fondness for fatty food and black tea showed an increased risk of renal cell carcinoma while an intake of starchy roots such as taro, sweet potato and potato reduced the risk of renal cell carcinoma. In Japan, however, drinking black tea may be a surrogate for westernized dietary habits while eating starchy roots may be a surrogate for traditional Japanese dietary habits. Further studies may be needed to evaluate risk factors for renal cell cancer because the number of renal cancer cases was small in our studies in spite of a large population-based cohort study.

Changes in Japanese Dietary Habits after the World War II and Their Implications for Energy Consumption

Changes in Japanese Dietary Habits after the World War II and Their Implications for Energy Consumption

戦後日本の食生活の変化の環境的意味に関する研究

戦後日本の食生活の変化の環境的意味に関する研究

An ecological study on diet/nutrition and cancer in Japan.

Correlation or ecological studies may be useful in identifying cancer risk factors which are distributed relatively homogeneously within a population, but differ greatly between populations or between different periods within a given population. In Japan, the westernization of dietary habits has progressed remarkably in the last few decades and may have resulted in changes of incidence/mortality rates of diet-related diseases, especially cancer. Based on data from the National Nutritional Survey of Japan (1955-1993) and the vital statistics of Japan (1955-1993), we conducted correlation analyses between food/nutrient intake and cancer mortality. The present study on chronological correlations suggests the relationship between westernized dietary habits and mortality by cancers of the colon, breast, ovary and prostate and also the relationship between traditional Japanese dietary habits and mortality by stomach cancer. Our results suggest the importance of diet in the etiology of diet-related cancer. Further observation and analyses are needed to confirm the relationship between food/nutrient intake and cancer mortality, while also considering the consumption of tobacco and alcohol and improvement in cancer diagnostic and therapeutic techniques.

Canadian Japanese Dietary Habits on Festival Occations.

目的: カナダBC州のバンクーバー, スティーブストン, フレーザーバリー在住の日系人の食生活における日本人としてのアイデンティティーの検索調査時期及び調査対象: 調査時期は1992年9-10月であり, 対象は27-90歳の日系二世および三世225名 (男子19名, 女子206名) である.結果: 1. 行事は, 西洋の行事 (クリスマス, ハローイン, イースター) と日本の行事 (正月, お盆, 雛祭り, 大晦日) が並列に行われており, 行事食は伝統的な形のものが残っていた. 日本の行事食として定着しているのは, 赤飯, 寿司, 煮しめ, 饅頭であった. こんにゃくは, 現在でも手作りされている.2. 正月料理の雑煮は, 丸餅を焼かずに煮込む白味噌または澄まし仕立てであり, 西日本の食文化が主流である.3. カナダでアレンジされた料理には, BCロールがあり, カリフォルニアロールと一緒にレストラン料理として定着している.4. 日系人独特の行事食としてチャーメンが定着していた.

Survey on Japanese Dietary Habits by Questionnair (Part 3)

Survey on Japanese Dietary Habits by Questionnair (Part 3)