Associations of Education With Overall Diet Quality Are Explained by Different Food Groups in Middle-aged and Old Japanese Women.

BACKGROUND: The disparity of overall diet quality by personal educational attainment has been a public issue. However, it remains unknown which food groups contribute to the disparity. This cross-sectional study assesses which food groups explain associations between education and overall diet quality in Japanese women. METHODS: A total of 3,788 middle-aged (mean age, 47.7 years) and 2,188 older women (mean age, 74.4 years), who lived in 47 prefectures in Japan, provided data on their education (low, middle, and high) and dietary intakes from a diet history questionnaire. A diet quality score (possible score 0-70) was calculated based on seven food components. Mean diet quality scores, with adjustment for lifestyle and neighborhood variables, were estimated by education using a general linear model, and Dunnett's multiple comparison was conducted. Additionally, mean scores of each food component were estimated by education and compared using the same manner. RESULTS: After adjustment for lifestyle and neighborhood variables, mean diet quality score of high or middle education was higher than low education for both generations. Middle-aged women with high and middle education had higher scores of 'milk', 'snacks, confection, and beverages', 'fruits', and 'vegetable dishes' than those with low education. Older women with high and middle education had higher scores of 'sodium from seasonings' and 'fruits' than those with low education. CONCLUSIONS: This study suggests that positive associations between education and diet quality are explained by different food groups in middle-aged and older Japanese women, which are independent of lifestyle and neighborhood variables.

Intake of Coffee Associated With Decreased Depressive Symptoms Among Elderly Japanese Women: A Multi-Center Cross-Sectional Study.

BACKGROUND: Depression in elderly people is a major global concern around the world. Epidemiological evidence of the association of beverages with depressive symptoms has received research attention; however, epidemiological studies on the association of coffee and green tea consumption with depressive symptoms among the elderly population are limited. The objective of this study is to cross-sectionally examine the association of depressive symptoms with the intake of coffee, green tea, and caffeine and to verify the antidepressant effect of caffeine. METHODS: The subjects were 1,992 women aged 65-94 years. Intakes of coffee, green tea, and caffeine, as well as depressive symptoms, were assessed with a validated brief dietary history questionnaire (BDHQ) and the Center for Epidemiologic Studies Depression Scale (CES-D), respectively. Multiple logistic regression analysis was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for depressive symptoms with adjustments for potential confounders. RESULTS: Coffee intake was associated with a lower prevalence of depressive symptoms, the ORs of which for the 4th versus the 1st quartiles of intake was 0.64 (95% CI, 0.46-0.88, P for trend = 0.01) in a fully adjusted model. Caffeine intake was marginally associated with depressive symptoms, but the association was not statistically significant (OR 0.75; 95% CI, 0.55-1.02, P for trend = 0.058). CONCLUSION: The result suggests that the inverse association of coffee intake with depressive symptoms might be associated with not only caffeine intake but also some other substances in coffee or factors related to coffee intake. Because of the cross-sectional design of the present study, longitudinal studies are required to confirm the present finding.

Dietary diversity score correlates with nutrient intake and monetary diet cost among Japanese adults.

BACKGROUND AND OBJECTIVES: Dietary diversity is an indicator of diet quality. Dietary diversity has been suggested to result in good nutrient intake, but it can affect dietary cost. We examined whether dietary diversity correlates with nutrient intake and monetary diet cost. METHODS AND STUDY DESIGN: We used data for 3985 individuals (age range: 20-64 years) from the 2014 Japan National Health and Nutrition Survey (NHNS). Dietary diversity was assessed using the food variety score (FVS; the number of foods) and dietary diversity score (DDS; the number of food groups, range: 1-14). Mean energy and nutrient intake from NHNS, and diet cost from the National Retail Price Survey were compared among FVS quartiles using the Kruskal-Wallis test, and between 2 groups with median DDS using the Mann-Whitney U test. RESULTS: Mean (SD) FVS and DDS per day were 22.3 (7.2) and 9.8 (2.0), respectively. For most nutrients, intake per 4184 kJ was relatively high when FVS was high (p<0.001); however, carbohydrate intake was relatively high in the low-FVS group (p<0.001). For all nutrients with significant differences, intake was higher in the group with high DDS (≥10). Monetary diet cost was higher in the high-FVS and DDS groups compared with the low groups (p<0.001). CONCLUSIONS: Intake of a variety of food and food groups resulted in higher intake of various nutrients as well as higher monetary diet cost. Additionally, care should be taken to avoid excessive intake of nutrients such as sodium and SFA that may result from diverse diets.

Household food unavailability due to financial constraints affects the nutrient intake of children.

BACKGROUND: A household's food unavailability due to financial constraints may act as a barrier to a healthy diet for children. This cross-sectional study aimed to examine the association between food unavailability due to financial constraints and the nutrient intake of children aged 1-15 years using data of a nationwide survey among the Japanese population. METHODS: Datasets from the National Health and Nutrition Survey and the Comprehensive Survey of Living Conditions in Japan, 2014 were used for this study. The dietary intakes of energy and nutrients were estimated using a one-day dietary record. Participants were categorized into four subgroups, according to their households' frequency of food unavailability due to financial constraints. The adjusted means and 95% confidential intervals of the energy and nutrient intakes in each subgroup were calculated using analysis of covariance. The statistical trends across the subgroups were examined using analysis of covariance. RESULTS: Of the 895 children included in the analysis, 202 (22.6%) were classified into subgroups with frequent food unavailability due to financial constraints. Significant decreases in the mean intakes of carbohydrate, calcium, retinol activity equivalents, riboflavin, folate and vitamin C were observed with increases in the frequency of households' food unavailability. In contrast, frequent food unavailability was associated with higher total fat and vitamin B12 intake. CONCLUSION: A substantial proportion of children in Japan experienced food unavailability due to financial constraints, and this affected their nutrient intake. Adopting a population approach may help overcome this problem.

Higher dietary acid load is associated with a higher prevalence of frailty, particularly slowness/weakness and low physical activity, in elderly Japanese women.

OBJECTIVE: Epidemiologic evidence on the potential effects of dietary acid load on frailty is lacking. This cross-sectional study examined the association between dietary acid load and frailty. METHODS: This study was based on self-reported data obtained from 2176 Japanese women aged 65-94 years. Dietary acid load was characterized as potential renal acid load (PRAL) and net endogenous acid production (NEAP), based on information on nutrient intake, obtained from a validated brief diet history questionnaire. Frailty score (0-5) was defined as the sum of slowness/weakness (two points), exhaustion (one point), low physical activity (one point), and unintentional weight loss (one point). A score of ≥3 was classified as indicating frailty. RESULTS: The prevalence of frailty was 17.9%. After adjustment for potential confounding factors, higher PRAL and NEAP were associated with a higher prevalence of frailty. Adjusted OR (95% CI) for frailty in the highest compared to the lowest quintiles was 1.59 (1.08, 2.34) for PRAL (P for trend = 0.048) and 1.42 (0.98, 2.06) for NEAP (P for trend = 0.03). PRAL and NEAP also showed positive associations with the prevalence of slowness/weakness and low physical activity (all P for trend ≤0.03). PRAL (but not NEAP) was positively associated with the prevalence of exhaustion (P for trend = 0.04). There was no association for unintentional weight loss. CONCLUSIONS: Dietary acid load was positively associated with the prevalence of frailty, particularly slowness/weakness and low physical activity, in elderly Japanese women.

Higher dietary glycemic index, but not glycemic load, is associated with a lower prevalence of depressive symptoms in a cross-sectional study of young and middle-aged Japanese women.

OBJECTIVE: Epidemiologic evidence on the associations between dietary glycemic index (GI) and glycemic load (GL) and depressive symptoms is not only limited, particularly in Asian populations where dietary GI and GL are typically higher than in Western countries, but also inconclusive. This cross-sectional study examined these associations in Japanese women. METHODS: Subjects were 3963 young (age 18-years) and 3826 middle-aged (mean age 47.8 years) Japanese women. Dietary GI and GL were assessed using a validated diet history questionnaire. Depression symptoms were defined as present when subjects had a Center for Epidemiologic Studies Depression score ≥16. RESULTS: The prevalence of depressive symptoms was 50.2% for young women and 27.3% for middle-aged women. The mean (SD) values of energy-adjusted dietary GI and GL (GI for glucose = 100) were, respectively, 64.9 (4.3) and 142.0 (27.4) for young women and 65.0 (4.1) and 142.2 (29.5) for middle-aged women. After adjustment for potential confounding factors, higher dietary GI was associated with a lower prevalence of depressive symptoms. Adjusted OR (95% CI) for depressive symptoms in the highest compared to lowest quintiles of dietary GI was 0.66 (0.52, 0.82) for young women (P for trend = 0.001) and 0.75 (0.60, 0.96) for middle-aged women (P for trend = 0.046). Conversely, there was no association between dietary GL and depressive symptoms in either age group. CONCLUSIONS: Dietary GI, but not GL, was inversely associated with depressive symptoms in a group of young and middle-aged Japanese women with relatively high dietary GI and GL.

Food-based diet quality score in relation to depressive symptoms in young and middle-aged Japanese women.

Only a few studies have focused on the association between overall diet, rather than intakes of individual nutrients or foods, and depressive symptoms in Japanese. This cross-sectional study examined associations between a diet quality score and depressive symptoms in 3963 young (age 18 years) and 3833 middle-aged (mean age 47·9 (sd 4·2) years) Japanese women. Dietary information was collected using a diet history questionnaire. A previously developed diet quality score was computed mainly based on the Japanese Food Guide Spinning Top. The prevalence of depressive symptoms was 22·0 % for young women and 16·8 % for middle-aged women, assessed as a Center for Epidemiologic Studies Depression (CES-D) score ≥23 and ≥19, respectively. As expected, the diet quality score was associated positively with intakes of 'grain dishes', 'vegetable dishes', 'fish and meat dishes', 'milk' and 'fruits' and inversely with intakes of energy from 'snacks, confection and beverages' and Na from seasonings. After adjustment for potential confounders, OR for depressive symptoms in the highest v. lowest quintiles of the diet quality score was 0·65 (95 % CI 0·50, 0·84) in young women (P for trend=0·0005). In middle-aged women, the corresponding value was 0·59 (95 % CI 0·45, 0·78) (P for trend<0·0001). Analyses where the diet quality and CES-D scores were treated as continuous variables also showed inverse associations. In conclusion, this cross-sectional study showed that a higher diet quality score was associated with a lower prevalence of depressive symptoms in young and middle-aged Japanese women. Prospective studies are needed to confirm a public health relevance of this finding.

Living status and frequency of eating out-of-home foods in relation to nutritional adequacy in 4,017 Japanese female dietetic students aged 18-20 years: A multicenter cross-sectional study.

BACKGROUND: Living status (e.g., living with family or alone) may affect dietary habits. We compared nutritional adequacy according to living status and the frequency of eating out-of-home foods in young Japanese women. METHODS: Female dietetic students (aged 18-20 years; n = 4,017) participated in a cross-sectional multicenter study, which was conducted in 85 dietetic schools in 35 of 47 prefectures in Japan. Habitual dietary intake was assessed with a validated diet history questionnaire. Nutritional adequacy was determined based on the Dietary Reference Intakes for Japanese, 2015, for two goals: preventing non-communicable chronic disease (a tentative dietary goal for preventing lifestyle-related diseases [DG] that tracks five nutrients) and avoiding insufficient intake of mainly vitamins and minerals (estimated average requirement [EAR] that tracks 14 nutrients). RESULTS: Women living with their family were less likely to meet DG nutrient levels, but more likely to meet EAR nutrient levels compared with those living alone. In contrast, women living alone had more inadequate nutrients with EAR and fewer nutrients with not-meeting DG than those living with families. A higher frequency of eating out-of-home was significantly associated with a higher prevalence of not-meeting DG nutrient levels only in the women living with their family. CONCLUSIONS: The prevalence of nutritional adequacy varied based on living status. In addition, women living with their family and those with a high frequency of eating out-of-home foods had the highest prevalence of not-meeting DG. Effective ways of improving dietary quality among young Japanese women differ by living status.

Diet with a combination of high protein and high total antioxidant capacity is strongly associated with low prevalence of frailty among old Japanese women: a multicenter cross-sectional study.

BACKGROUND: The intake of protein and antioxidants has been inversely associated with frailty, individually. However, to our knowledge, no study has evaluated these associations in considering antioxidants or protein intakes as respective confounders. Further, the cooperative effect of dietary protein and antioxidants on frailty has not been investigated. Therefore, we examined the association of high protein and high dietary total antioxidant capacity (TAC) with frailty under the adjustment for dietary TAC or protein intake, respectively. The association between the combination of high dietary protein and high dietary TAC and frailty was also investigated. METHODS: A total of 2108 grandmothers or acquaintances of dietetic students aged 65 years and older participated in this cross-sectional multicenter study conducted in 85 dietetic schools in Japan. Dietary variables, including protein intake, and dietary TAC were estimated from a validated brief-type self-administered diet history questionnaire. Frailty was defined as a score of three or more points obtained from the following four components: slowness and weakness (two points), exhaustion, low physical activity, and unintentional weight loss. RESULTS: Median (interquartile range) age of the present subjects was 74 (71-78) years. Multivariate adjusted ORs (95% CIs) for frailty in the highest compared to the lowest tertile were 0.66 (0.49, 0.87) for total protein intake (P for trend = 0.003) and 0.51 (0.37, 0.69) for dietary TAC (P for trend <0.0001) after adjustment for dietary TAC or total protein intake, respectively. The OR of frailty for the group with both the highest tertiles of total protein intake and dietary TAC was markedly lower (multivariate adjusted OR [95% CIs]: 0.27 [0.16, 0.44]; P <0.0001) compared to the group with the lowest tertile of protein intake and the lowest tertile of dietary TAC. CONCLUSIONS: Both protein intake and dietary TAC were independently inversely associated with frailty among old Japanese women. Further, a diet with the combination of high dietary protein and high dietary TAC was strongly inversely associated with the prevalence of frailty in this population. To select food combinations that allow for an increase of both protein and antioxidants in diet according to the local food culture and dietary habits may be an effective strategy for frailty prevention.

Food intake patterns and cardiovascular risk factors in Japanese adults: analyses from the 2012 National Health and nutrition survey, Japan.

BACKGROUND: There is an increasing global interest in the role of Japanese diet as a possible explanation for the nation's healthy diet, which contributes to the world's highest life-expectancy enjoyed in Japan. However, nationwide studies on current food intake status among general Japanese population have not been established yet. This study examined the association between food intake patterns and cardiovascular risk factors (CVRF) such as waist circumference (WC), body mass index (BMI), blood pressure (SBP, DBP), HbA1c and blood lipid profiles among general Japanese adults. METHODS: De-identified data on the Japan National Health and Nutrition Survey (NHNS) 2012 with a total of 11,365 subjects aged 20-84 years were applied. Food intake patterns were derived by principal component analysis (PCA) based on 98 food groups. Generalized linear regression analysis was used to assess the relation between the food intake patterns and CVRF. RESULTS: We identified three food intake patterns: traditional Japanese, Westernized, and meat and fat patterns. Traditional Japanese pattern was significantly related to high WC and BMI in men, and high DBP in women. Westernized pattern was associated with lower SBP, but high total cholesterol and LDL cholesterol in both men and women. Meat and fat pattern was associated with high WC, high BMI, high blood pressure and blood lipid profiles in both men and women (trend P < 0.001). CONCLUSION: The significant association between cardiovascular disease risks and three food intake patterns derived from the NHNS, showed a similar tendency to other dietary survey methods.

A Japanese diet with low glycaemic index and glycaemic load is associated with both favourable and unfavourable aspects of dietary intake patterns in three generations of women.

OBJECTIVE: Western studies have suggested cultural differences in food and nutrient intake patterns associated with dietary glycaemic index (GI) and glycaemic load (GL). Here, we conducted a cross-sectional study to examine the GI and GL of Japanese diets in relation to food and nutrient intakes. DESIGN: Dietary intake was assessed using a validated, self-administered, diet history questionnaire. SETTING: A total of thirty-five of forty-seven prefectures in Japan. SUBJECTS: Young (age 18 years), middle-aged (mean age 48 years) and older (mean age 74 years) Japanese women (n 3961, 3800 and 2202, respectively). RESULTS: Irrespective of age, a positive association with dietary GI was seen for white rice only, which contributed most (37-42 %) to the variation in dietary GI. Conversely, all other food groups (such as fruit and vegetable juice, dairy products, noodles and fruit) were negative predictors of dietary GI. For dietary GL, 95-96 % of variation was explained by carbohydrate-rich food groups, all of which were positive predictors of GL. After adjustment for potential confounding factors, only carbohydrate intake was positively associated with dietary GI and GL, irrespective of age. Conversely, dietary GI and GL were inversely associated with intakes of all other nutrients examined (including SFA and Na). CONCLUSIONS: A low-GI and -GL diet, which was characterized principally by a low intake of white rice, was associated with both favourable (higher intakes of dietary fibre and key vitamins and minerals) and unfavourable (higher intakes of SFA and Na) aspects of dietary intake patterns in three generations of Japanese women.

Cohabitational effect of grandparents on dietary intake among young Japanese women and their mothers living together. A multicenter cross-sectional study.

We examined the cohabitational effect of the grandparents on dietary intakes among young Japanese women and their mothers, using data from a cross-sectional multicenter study conducted in 35 of 47 prefectures in Japan. Among a total of 2032 three-generation families, 1336 female dietetic students (18-20 years), 1336 of their mothers (36-59 years), and 1560 of their paternal or maternal grandmothers (59-94 years) were included. Intake of foods and nutrients was assessed with self-administered diet history questionnaires. The prevalence of students and their mothers living with the grandparents (GP) was 36%. Students living with GP had a higher intake of fruits, vegetables, total dietary fiber, ß-carotene, vitamin C and potassium and lower intake of meats than those living without GP. For mothers, fish and shellfish and vitamin C intakes were higher and meat intake was lower among participants living with GP. The median correlation coefficients of food and nutrient intakes in the students-grandmothers living together was higher than in those living apart for both paternal grandmothers (PGM) and maternal grandmothers (MGM) (all P <0.01). The median values of mothers-PGM living together were also significantly higher than in those living apart (P <0.01). However, the values of mothers-MGM did not significantly differ between those living with and without MGM. These results may suggest that family members who live together tend to share similar dietary habits. Further, the mother's dietary habits might affect those of their children even after they live apart.

Effect of seasonality on the estimated mean value of nutrients and ranking ability of a self-administered diet history questionnaire.

BACKGROUND: We examined the effect of seasonality on the validity (ability to estimate the mean intake of a group and ranking ability) of nutrient intakes estimated with a comprehensive self-administered diet history questionnaire (DHQ) developed for the assessment of Japanese diets during the preceding one month, using semi-weighed dietary records (DRs) as a reference method. METHODS: This study was conducted in three areas in Japan (Osaka, Nagano, and Tottori). The study population included 92 Japanese men aged 32-76 years and 92 Japanese women aged 31-69 years (30 from Osaka, 31 from Nagano, and 31 from Tottori for each sex). A DHQ and a four-day DR were completed four times at 3-month intervals, once per season. The effect of seasonality was examined by the level of agreement among seasons using mean nutrient intake and correlation coefficients. RESULTS: Significant differences in estimated energy-adjusted intakes of 42 selected nutrients between the average of DRs administered 16 times throughout a year and that of the DHQ administered four times in each season (fall, winter, spring, and summer) were observed for 30, 29, 30, and 31 nutrients for men and 21, 28, 30, and 31 nutrients for women, respectively. Pearson correlation coefficients between the DRs and the DHQs for energy-adjusted intakes of the 42 nutrients showed significant inter-season differences in 11 nutrients for men and 13 nutrients for women. Particularly, correlation coefficients of fat, monounsaturated fat, polyunsaturated fat, n-6 polyunsaturated fat, α-linolenic acid, and cholesterol in spring and cryptoxanthin in summer for men, and fat, saturated fat, and monounsaturated fat in spring and summer and thiamin and iron in summer for women were markedly altered by seasonality. CONCLUSIONS: Mean nutrient intake estimated by the DHQ varied by season, indicating that any consideration of nutrient intake estimated by the DHQ as a yearly average intake may be problematic. In contrast, the effect of seasonality on the ranking ability of the DHQ was relatively small, and thus the use of a DHQ to rank individuals by nutrient intake is acceptable for epidemiological studies, regardless of season.

High protein intake is associated with low prevalence of frailty among old Japanese women: a multicenter cross-sectional study.

BACKGROUND: Protein intake has been inversely associated with frailty. However, no study has examined the effect of the difference of protein sources (animal or plant) or the amino acid composing the protein on frailty. Therefore, we examined the association of protein and amino acid intakes with frailty among elderly Japanese women. METHODS: A total of 2108 grandmothers or acquaintances of dietetic students aged 65 years and older participated in this cross-sectional multicenter study, which was conducted in 85 dietetic schools in 35 prefectures of Japan. Intakes of total, animal, and plant protein and eight selected amino acids were estimated from a validated brief-type self-administered diet history questionnaire and amino acid composition database. Frailty was defined as the presence of three or more of the following four components: slowness and weakness (two points), exhaustion, low physical activity, and unintentional weight loss. RESULTS: The number of subjects with frailty was 481 (23%). Adjusted ORs (95% CI) for frailty in the first, second, third, fourth, and fifth quintiles of total protein intake were 1.00 (reference), 1.02 (0.72, 1.45), 0.64 (0.45, 0.93), 0.62 (0.43, 0.90), and 0.66 (0.46, 0.96), respectively (P for trend = 0.001). Subjects categorized to the third, fourth, and fifth quintiles of total protein intake (>69.8 g/d) showed significantly lower ORs than those to the first quintile (all P <0.03). The intakes of animal and plant protein and all selected amino acids were also inversely associated with frailty (P for trend <0.04), with the multivariate adjusted OR in the highest compared to the lowest quintile of 0.73 for animal protein and 0.66 for plant protein, and 0.67-0.74 for amino acids, albeit that the ORs for these dietary variables were less marked than those for total protein. CONCLUSIONS: Total protein intake was significantly inversely associated with frailty in elderly Japanese women. The association of total protein with frailty may be observed regardless of the source of protein and the amino acid composing the protein.

Cross-Sectional Associations of Intakes of Starch and Sugars with Depressive Symptoms in Young and Middle-Aged Japanese Women: Three-Generation Study of Women on Diets and Health.

The relationship between the intakes of saccharide subtypes and depressive symptoms is unclear in Asian countries. This cross-sectional study aimed to investigate this association among 3963 young (age of 18 years) and 3826 middle-aged (mean age of 47.8 years) Japanese women. The intakes of starch, total sugars, free sugars, sucrose, lactose, glucose, and total fructose were assessed using a validated diet history questionnaire. The prevalence of depressive symptoms was 22.0% and 16.8% among young and middle-aged women, assessed using the Center for Epidemiologic Studies Depression (CES-D) score. After adjusting for potential confounding factors, higher starch intake was associated with a lower prevalence of depressive symptoms in young women with an odds ratio (OR) of the fourth to the first quintiles of 0.75 (95% confidence interval (CI): 0.57, 0.99). Moreover, higher intakes of sugars (except for lactose) were associated with a higher prevalence of depressive symptoms in young women, with ORs (95% CI) of the fifth to the first quintiles ranging from 1.30 (0.995, 1.69) for glucose to 1.47 (1.12, 1.93) for sucrose. These associations were not observed in middle-aged women. Future prospective studies are needed to confirm these findings.

Age threshold for recommending higher protein intake to prevent age-related muscle weakness: A cross-sectional study in Japan.

Although insufficient dietary protein intake is a known risk factor for age-related muscle weakness, the optimal age at which higher protein intake is required to prevent muscle weakness is yet to be determined. Using a population-based panel survey of community-dwelling people aged 50-75 years, this cross-sectional study aimed to find the age threshold at which a higher protein intake is associated with higher muscle strength. We utilized a dataset from the Japanese Study of Aging and Retirement conducted between 2007 and 2011. Dietary protein intake was estimated using a validated dietary questionnaire and energy-adjusted via density method. Grip strength was measured using a Smedley-type handheld dynamometer. We calculated the marginal effect (and 95% confidence intervals) of protein intake on grip strength with stratification by age using multiple linear regression analyses with robust variance adjusting for potential confounders. There were 9,485 observations from 5,790 participants in the final analysis. Marginal effects of protein intake on grip strength increased with age, and it reached significance and had a positive impact only among men aged ≥75 years and women aged ≥65 years. With an additional 1% energy of protein intake, grip strength was increased by 0.10 kg and 0.19 kg for men and women aged ≥75 years, respectively. Our result indicated the possibility that women needed a high protein intake from a younger age compared with men. Further studies are needed to clarify from when a higher protein intake is recommended to prevent muscle weakness.

Association between habitual tryptophan intake and depressive symptoms in young and middle-aged women.

BACKGROUND: The intake of tryptophan, the precursor of serotonin, is assumed to affect serotonin availability and depression onset. Nevertheless, a definitive relationship between dietary tryptophan intake and depressive symptoms has not been established. We examined the association between tryptophan intake and depressive symptoms screened in a group of 4272 first-year female dietetic students and 3651 their mothers. METHODS: Dietary tryptophan intake during the preceding month was assessed with a validated, self-administered diet history questionnaire. Depressive symptoms were assessed with the Center for Epidemiologic Studies Depression Scale (CES-D) using two cutoff scores: CES-D score ≥ 16 and CES-D score ≥ 19 (the optimal cutoff score for Japanese people). The multivariate adjusted prevalence ratio (PR) and 95% confidence interval (CI) for depressive symptoms were calculated using Poisson regression analysis. RESULTS: The prevalence of depressive symptoms (CES-D score ≥ 16) was 50.0% for young women and 26.5% for middle-aged women. The adjusted PR (95% CI) for depressive symptoms in the highest versus lowest quintile of tryptophan intake was 0.84 (0.75, 0.93) in young women (P for trend < 0.0001) and 0.83 (0.64, 1.01) in middle-aged women (P for trend < 0.0001). These associations were stable even when depressive symptoms were defined as a CES-D score ≥ 19. LIMITATIONS: This is a cross-sectional study. Depressive symptoms were assessed using a self-reported questionnaire. CONCLUSIONS: This cross-sectional study showed that a higher tryptophan intake was independently associated with a lower prevalence of depressive symptoms in young Japanese women.

Validation study of a self-administered diet history questionnaire for estimating amino acid intake among Japanese adults.

BACKGROUND AND OBJECTIVES: Despite growing interest in the association between dietary amino acid intake and optimal health, validated dietary questionnaires that can estimate amino acid intake have been scarce. We examined the validity of amino acid intakes estimated using a self-administered diet history questionnaire (DHQ) comparing with 16-day semi-weighed dietary records (DR). METHODS AND STUDY DESIGN: A total of 184 Japanese men and women completed a four-day DR and a DHQ four times, once in each season. Dietary amino acid intakes were estimated as crude, energy-adjusted, and percentage of total protein intake (% protein) using an amino acid database of Japanese foods. The validity of dietary amino acid intake estimated by the first-time DHQ was examined using the mean of 16 days' DRs as reference. RESULTS: Mean intakes of almost all amino acids estimated by DHQ were significantly lower than those estimated by the DR for energy-adjusted values in both sexes. Although mean amino acid intakes estimated by DHQ were significantly higher than those estimated by the DR for % protein value, the differences between the DR and DHQ were slight (-0.04 to 0.39% protein for men, -0.05 to 0.37% protein for women). Pearson correlation coefficients between DHQ and the DR showed reasonable ranking ability in % protein values for men (interquartile range (Q1-Q3): 0.31-0.47) and energy-adjusted values for women (interquartile range (Q1-Q3): 0.40-0.45). CONCLUSION: DHQ showed acceptable ability to estimate mean amino acid intake and to rank individuals in a population according to their amino acid intake for using in large-scale epidemiological studies.

Dietary pattern and its association with blood pressure and blood lipid profiles among Japanese adults in the 2012 Japan National Health and Nutrition Survey.

BACKGROUND AND OBJECTIVES: Little is known about the association between dietary patterns and cardiovascular disease risk factors among Japanese adults based on nationally representative data. This study aimed to explore the association between dietary patterns and hypertension or blood lipid profiles among Japanese people. METHODS AND STUDY DESIGN: De-identified Japan National Health and Nutrition Survey (NHNS) 2012 data with a total of 8721 subjects (3524 men and 5197 women) aged 40-74 years were used. Dietary patterns were derived by principal component analysis (PCA). Generalized linear models and multivariate logistic regression analysis were used to assess the relationship between dietary patterns and blood pressure or lipid profiles. RESULTS: We identified four dietary patterns: (a) traditional Japanese, (b) bread-dairy, (c) meat-fat, and (d) noodle patterns. Among these, the traditional Japanese pattern was significantly related to lower blood pressure, lower low-density lipoprotein (LDL)-cholesterol in men and lower high-density lipoprotein (HDL)-cholesterol in women. Bread-dairy pattern was associated with high total cholesterol in women and higher LDL cholesterol in both men and women. Noodle pattern was associated with higher total cholesterol and HDL-cholesterol in men. No significant association was observed between meat-fat pattern and blood pressure or lipid profiles. CONCLUSIONS: Our study showed that the traditional Japanese pattern with high intake of miso, soy-sauce, vegetables, beans, potatoes and mushroom conferred benefits on blood pressure. Our findings have indicated clearly that it is possible to provide useful information on healthy dietary pattern for health promotion from the one-day dietary records of the NHNS.

Nutritional correlates of monetary diet cost in young, middle-aged and older Japanese women.

Studies in many Western countries have consistently shown that monetary diet cost is positively associated with diet quality, but this may not necessarily be the case in Japan. This cross-sectional study examined the nutritional correlates of monetary diet cost among 3963 young (all 18 years old), 3800 middle-aged (mean age 48 years) and 2211 older (mean age 74 years) Japanese women. Dietary intakes were assessed using a comprehensive self-administered diet history questionnaire for young and middle-aged women and a brief self-administered diet history questionnaire for older women. Monetary diet cost was estimated using retail food prices. Total vegetables, fish and shellfish, green and black tea, white rice, meat, fruit and alcoholic beverages contributed most (79-89 %) to inter-individual variation in monetary diet cost. Multiple regression analyses showed that monetary diet cost was negatively associated with carbohydrate intake, but positively with intakes of all other nutrients examined (including not only dietary fibre and key vitamins and minerals but also saturated fat and Na) in all generations. For food group intakes, irrespective of age, monetary diet cost was associated inversely with white rice and bread but positively with pulses, potatoes, fruit, total vegetables, fruit and vegetable juice, green and black tea, fish and shellfish, and meat. In conclusion, in all three generations of Japanese women and contrary to Western populations, monetary diet cost was positively associated with not only healthy dietary components (including fruits, vegetables, fish and shellfish, dietary fibre, and key vitamins and minerals), but also less healthy components (including saturated fat and Na).