Periconceptional maternal diet quality and offspring wheeze trajectories: Japan Environment and Children's Study.

BACKGROUND: The role of prenatal diet on childhood wheezing and subsequent risk of asthma is inconclusive, which may be partly due to the heterogeneity in wheezing phenotypes. We aimed to identify wheeze trajectories in early childhood and to examine their associations with periconceptional maternal diet quality. METHODS: Data from 70,530 mother-child pairs of liveborn singletons from the Japan Environment and Children's Study were analysed. Wheezing was reported by caregivers using a modified International Study of Asthma and Allergies in Childhood questionnaire yearly from 1 to 4 years of age, from which trajectories were derived using group-based trajectory modelling. Maternal diet in the year preceding the first trimester of pregnancy was assessed using a validated food frequency questionnaire; overall diet quality was determined using the balanced diet score based on the Japanese Food Guide Spinning Top. Bayesian inference of multinomial logistic regression models was performed to examine the association between maternal diet quality and wheeze trajectory in early childhood. RESULTS: We identified four wheeze trajectories: 'never/infrequent' (69.1%; reference group), 'early-childhood onset' (6.2%), 'transient early' (16.5%) and 'persistent' (8.2%). After adjustment for confounders, a higher quartile of maternal balanced diet score was associated with a lower risk of belonging to the 'transient early' and 'persistent' wheeze trajectories compared with the 'never/infrequent' wheeze trajectory by 10% of both. Maternal balanced diet score was not associated with belonging to the 'early-childhood onset' wheeze trajectory. CONCLUSION: Improving maternal diet quality prior to conception may reduce certain wheeze phenotypes in early childhood.

Nut consumption during pregnancy is associated with decreased risk of peer problems in 5-year-old Japanese children.

OBJECTIVES: Nuts are nutrient-dense foods rich in unsaturated fatty acids, protein, dietary fiber, vitamins, and minerals. The present prebirth cohort study examined the association between maternal nut intake during pregnancy and the risk of childhood behavioral problems in 5-year-old Japanese children. METHODS: Study subjects were 1199 mother-child pairs. Dietary intake was assessed using a diet history questionnaire. Emotional problems, conduct problems, hyperactivity problems, peer problems, and low prosocial behavior were assessed using the parent-reported version of the Strengths and Difficulties Questionnaire. Adjustments were made for a priori-selected nondietary confounders and potentially related dietary factors. RESULTS: Compared with mothers who had not eaten nuts during pregnancy, mothers who had eaten nuts had a significantly reduced risk of peer problems in children; the adjusted odds ratio was 0.64 (95% confidence interval: 0.42-0.97). There were no measurable associations between maternal consumption of nuts during pregnancy and the risk of childhood emotional problems, conduct problems, hyperactivity problems, and low prosocial behavior. CONCLUSIONS: Maternal consumption of nuts during pregnancy may be associated with a decreased risk of peer problems in 5-year-old children.

Coffee and caffeine intake reduces risk of ulcerative colitis: a case-control study in Japan.

BACKGROUND AND AIM: Although diet is one of the potential environmental factors affecting ulcerative colitis (UC), evidence is not sufficient to draw definitive conclusions. This Japanese case-control study examined the association between the consumption of coffee, other caffeine-containing beverages and food, and total caffeine and the risk of UC. METHODS: The study involved 384 UC cases and 665 control subjects. Intake of coffee, decaffeinated coffee, black tea, green tea, oolong tea, carbonated soft drinks, and chocolate snacks was measured with a semiquantitative food-frequency questionnaire. Adjustments were made for sex, age, pack-years of smoking, alcohol consumption, history of appendicitis, family history of UC, education level, body mass index, and intake of vitamin C, retinol, and total energy. RESULTS: Higher consumption of coffee and carbonated soft drinks was associated with a reduced risk of UC with a significant dose-response relationship (P for trend for coffee and carbonated soft drinks were <0.0001 and 0.01, respectively), whereas higher consumption of chocolate snacks was significantly associated with an increased risk of UC. No association was observed between consumption of decaffeinated coffee, black tea, green tea, or oolong tea and the risk of UC. Total caffeine intake was inversely associated with the risk of UC; the adjusted odds ratio between extreme quartiles was 0.44 (95% confidence interval: 0.29-0.67; P for trend <0.0001). CONCLUSIONS: We confirmed that intake of coffee and caffeine is also associated with a reduced risk of UC in Japan where people consume relatively low quantities of coffee compared with Western countries.

Maternal fat intake in pregnancy and risk of depressive symptoms in Japanese adolescents: the Kyushu Okinawa Maternal and Child Health Study.

The current prebirth cohort study investigated the association between maternal intake of specific types of fatty acids during pregnancy and adolescent depressive symptoms based on the Center for Epidemiologic Studies Depression Scale. Subjects were 873 mother-child pairs. Dietary intake during the preceding month was assessed using a self-administered diet history questionnaire. The risk of depressive symptoms was 23.3% among the 873 adolescents at 13 years of age. Higher maternal saturated fatty acid intake during pregnancy was independently associated with a reduced risk of depressive symptoms in adolescents. Maternal intake of total fat, monounsaturated fatty acids, n-3 polyunsaturated fatty acids, α-linolenic acid, eicosapentaenoic acid, docosahexaenoic acid, n-6 polyunsaturated fatty acids, linoleic acid, arachidonic acid and cholesterol during pregnancy was not significantly related to depressive symptoms in adolescents. Higher maternal intake of saturated fatty acids during pregnancy may be inversely associated with adolescent depressive symptoms.

Periconceptional diet quality and its relation to blood heavy metal concentrations among pregnant women: The Japan environment and Children's study.

BACKGROUND: Diets contain toxic chemical contaminants as well as essential nutrients, both of which influence the intrauterine environment for foetal growth. However, whether a high-quality diet that is nutritionally healthy also results in lower exposure to chemical contaminants is unknown. OBJECTIVE: We examined associations between periconceptional maternal diet quality and circulating concentrations of heavy metals during pregnancy. DESIGN: Dietary intake over the year prior to the first trimester of pregnancy was assessed using a validated, self-administered food frequency questionnaire among 81,104 pregnant Japanese women who participated in the Japan Environment and Children's Study. Overall diet quality was determined using the Balanced Diet Score (BDS) based on the Japanese Food Guide Spinning Top, the Healthy Eating Index-2015 (HEI-2015), the Dietary Approaches to Stop Hypertension (DASH) score and the Mediterranean diet score (MDS). We measured whole-blood concentrations of mercury (Hg), lead (Pb) and cadmium (Cd) during the second or third trimester of pregnancy. RESULTS: After controlling for confounders, all diet quality scores were positively associated with blood Hg concentrations. By contrast, higher BDS, HEI-2015 and DASH scores were associated with lower concentrations of Pb and Cd. Although the MDS was positively associated with concentrations of Pb and Cd, when dairy products were classified as a beneficial (rather than detrimental) food component, these associations were attenuated. CONCLUSION: A high-quality diet may reduce exposure to Pb and Cd but not Hg. Further studies are required to determine the optimal balance between mercury exposure risk and nutritional benefits of high-quality diets prior to pregnancy.

Exploring culturally acceptable, nutritious, affordable and low climatic impact diet for Japanese diets: proof of concept of applying a new modelling approach using data envelopment analysis.

A future sustainable dietary pattern for Japanese is yet undefined. This study aimed to explore more sustainable Japanese diets that are nutritious, affordable and with low greenhouse gas emissions (GHGE) and particular emphasis on cultural acceptability. A newly developed data envelopment analysis (DEA) diet model was applied to 4-d dietary record data among 184 healthy Japanese men and 185 women volunteers aged 21-69 years. Alternative diets were calculated as the linear combinations of observed diets. Firstly, for each individual, four modelled diets were calculated that maximised cultural acceptability (i.e. minimise dietary change from observed diet), maximised nutritional quality assessed by the Nutrient-Rich Food Index (NRF), minimised monetary diet costs or minimised diet-related GHGE. The final modelled diet combined all four indicators. In the first four models, the largest improvement was obtained for each targeted indicator separately, while relatively small improvements or unwanted changes were observed for other indicator. When all indicators were aimed to optimise, the NRF score and diet-related GHGE were improved by 8-13 % with the lower monetary cost than observed diets, although the percentage improvement was a bit smaller than the separate models. The final modelled diets demanded increased intakes for whole grains, fruits, milk/cream/yogurt, legumes/nuts, and decreased intakes for red and processed meat, sugar/confectioneries, alcoholic and sweetened beverages, and seasonings in both sexes. In conclusion, more sustainable dietary patterns considering several indicators are possible for Japanese, while total improvement is moderate due to trade-offs between indicators and methodological limitation of DEA diet model.

Tryptophan intake is related to a lower prevalence of depressive symptoms during pregnancy in Japan: baseline data from the Kyushu Okinawa Maternal and Child Health Study.

OBJECTIVE: Tryptophan is an essential amino acid wholly derived from diet. While the majority of tryptophan is degraded through the kynurenine pathway into neuroactive metabolites like quinolinic acid and kynurenic acid, a small proportion of ingested tryptophan is metabolized into the neurotransmitter serotonin. The current cross-sectional study in Japan examined the association between tryptophan intake and depressive symptoms during pregnancy. METHODS: Study subjects were 1744 pregnant women. Dietary intake during the preceding month was assessed using a self-administered diet history questionnaire. Depressive symptoms were defined as a score ≥ 16 on the Center for Epidemiologic Studies Depression Scale. Adjustment was made for age, gestation, region of residence, number of children, family structure, history of depression, family history of depression, smoking, secondhand smoke exposure at home and at work, employment, household income, education, body mass index, and intake of saturated fatty acids, eicosapentaenoic acid plus docosahexaenoic acid, calcium, vitamin D, and isoflavones. RESULTS: The prevalence of depressive symptoms during pregnancy was 19.2%. After adjustment for confounding factors, higher tryptophan intake was independently inversely associated with the prevalence of depressive symptoms during pregnancy: the adjusted prevalence ratios (95% confidence intervals) for depressive symptoms during pregnancy in the first, second, third, and fourth quartiles of tryptophan intake were 1 (reference), 0.99 (0.76-1.28), 0.94 (0.71-1.25), and 0.64 (0.44-0.93), respectively (p for trend = 0.04). CONCLUSIONS: Higher estimated tryptophan intake was cross-sectionally independently associated with a lower prevalence of depressive symptoms during pregnancy in Japanese women.

Maternal metal intake during pregnancy and childhood behavioral problems in Japan: the Kyushu Okinawa Maternal and Child Health Study.

OBJECTIVES: Lower maternal metal intake during pregnancy might affect childhood development. The current prebirth cohort study investigated the relationship between maternal intake of zinc, magnesium, iron, copper, and manganese during pregnancy and behavioral problems in Japanese children aged five years. METHODS: Subjects were 1199 mother-child pairs. Dietary intake during the preceding month was assessed using a diet history questionnaire. Emotional, conduct, hyperactivity, and peer problems and low prosocial behavior were assessed using the Strengths and Difficulties Questionnaire. Maternal age, gestation at baseline, region of residence, number of children, maternal and paternal education, household income, maternal depressive symptoms during pregnancy, maternal alcohol intake during pregnancy, maternal smoking during pregnancy, child's birth weight, child's sex, breastfeeding duration, smoking in the household during the first year of life, and some dietary confounders that were associated with outcomes under study in this population were adjusted for. RESULTS: Compared with maternal magnesium intake during pregnancy in the first quartile, magnesium intake in the second, third, and fourth quartiles was independently inversely related to childhood hyperactivity problems, but not to emotional, conduct, or peer problems or low prosocial behavior: the adjusted odds ratio between extreme quartiles was 0.48 (95% confidence interval: 0.23-0.99, P for trend = 0.04). No evident associations were observed between maternal intake of zinc, iron, copper, or manganese during pregnancy and childhood emotional, conduct, hyperactivity, or peer problems or low prosocial behavior. CONCLUSIONS: The present study suggests that higher maternal magnesium intake during pregnancy is inversely associated with hyperactivity problems in Japanese children.

Calcium intake during pregnancy is associated with decreased risk of emotional and hyperactivity problems in five-year-old Japanese children.

Background: Recently, more attention has been paid to behavioral problems in children. However, for the most part, risk factors for these problems have yet to be determined.Objective: The current prebirth cohort study investigated the relationship between maternal calcium consumption during pregnancy and behavioral problems in five-year-old Japanese children.Methods: Subjects were 1199 mother-child pairs. Dietary intake during the preceding month was assessed using a self-administered diet history questionnaire. Emotional problems, conduct problems, hyperactivity problems, and peer problems were assessed using the Strengths and Difficulties Questionnaire. Logistic regression analysis was conducted to estimate odds ratios (ORs) and 95% confidence intervals (CIs).Results: Compared with the lowest quartile of maternal calcium intake, the highest was significantly associated with decreased risk of childhood emotional problems: the adjusted OR (95% CIs) was 0.46 (0.27-0.79, P for trend = 0.01). Higher maternal calcium intake during pregnancy was also independently associated with decreased risk of childhood hyperactivity problems; the adjusted ORs (95% CIs) in the first, second, third, and fourth quartiles of maternal calcium intake during pregnancy were 1 (reference), 0.52 (0.31-0.84), 0.58 (0.35-0.93), and 0.60 (0.37-0.97), respectively (P for trend = 0.046). No such inverse associations were observed for childhood conduct problems or peer problems; the adjusted ORs (95% CIs) in the highest quartile of maternal calcium intake were 0.97 (0.64-1.47) for conduct problems and 1.11 (0.61-2.01) for peer problems.Conclusions: Maternal calcium intake during pregnancy may decrease the risk of childhood emotional and hyperactivity problems.

Maternal caffeine intake during pregnancy and risk of food allergy in young Japanese children.

AIM: To examine the association between maternal caffeine intake during pregnancy and the development of food allergy in young Japanese children up to 3 years of age. METHODS: The study involved 1522 mother-child pairs. Data on maternal caffeine intake during pregnancy were assessed with a validated diet history questionnaire. Food allergy was defined by a self-reported claim of having a physicians' diagnosis of food allergy or of having an acute reaction to a food. RESULTS: Compared with the lowest tertile of maternal caffeine intake during pregnancy, the second tertile, but not the highest tertile, was significantly associated with an increased risk of food allergy. Further adjustment on suspicion or diagnosis of atopic eczema at around 4 months postpartum in a follow-up survey did not substantially change the association between maternal caffeine intake during pregnancy and the risk of food allergy in children: further adjusted hazard ratios (95% confidence intervals) for the second (T2), the highest tertiles (T3) and the second and the highest tertiles combined (T2 + T3) were 1.46 (1.10-1.96), 1.16 (0.85-1.56) and 1.31 (1.01-1.70), respectively. CONCLUSIONS: Our findings suggest that maternal caffeine intake during pregnancy may be positively associated with the risk of food allergy in children.

Maternal consumption of soy and isoflavones during pregnancy and risk of childhood behavioural problems: the Kyushu Okinawa Maternal and Child Health Study.

It is uncertain whether the effects of prenatal exposure to isoflavones on childhood behaviour are beneficial or detrimental. This prebirth cohort study investigated the associations between maternal consumption of soy products and isoflavones during pregnancy and behavioural problems in Japanese children aged 5 years. Subjects were 1199 mother-child pairs. Emotional problems, conduct problems, hyperactivity problems, peer problems and low prosocial behaviour were assessed using the Strengths and Difficulties Questionnaire. Maternal total soy product consumption during pregnancy was independently inversely associated with childhood hyperactivity and peer problems. Maternal fermented soybean consumption during pregnancy was independently inversely associated with childhood hyperactivity problems. Maternal isoflavone consumption during pregnancy was independently inversely related to childhood hyperactivity problems. Maternal consumption of total soy products, fermented soybean and isoflavones during pregnancy may be protective against hyperactivity problems in Japanese children. Also, maternal total soy product consumption during pregnancy may be preventive against childhood peer problems.

Sociodemographic Factors Influenced Response to the 2015 National Nutrition Survey on Preschool Children: Results From Linkage With the Comprehensive Survey of Living Conditions.

BACKGROUND: The National Nutrition Survey on Preschool Children, Japan (NNSPC) provides fundamental information for policy making for child nutrition. However, the response rate and background characteristics of subjects are unclear. Here, we examined response rate and sociodemographic factors related with response to the survey and evaluated the magnitude of bias due to selective response in the survey estimates of the NNSPC. METHODS: This study was based on two national surveys conducted in 2015: the NNSPC and the Comprehensive Survey of Living Conditions (CSLC). Because potential survey participants of the NNSPC were children aged <6 years and their households that answered the CSLC, we examined response rates and respondent characteristics by linking the data of the NNSPC and CSLC. Multiple logistic regression analysis was used to identify sociodemographic factors associated with response. Potential bias caused by non-response in the survey estimates was examined after considering missingness through multiple imputation. RESULTS: Among the 5,343 children who participated in the CSLC, 3,426 children responded to the NNSPC (response rate = 64.1%). Variables associated with response were living in a smaller city, a large number of children, three-generation family structure, older maternal age, and a non-working mother. The prevalence of overweight was underestimated by 20%, but the bias for almost all variables examined was small. CONCLUSIONS: Response to the survey varied by sociodemographic characteristics. Some biases, mostly small, were seen in survey estimates of the 2015 NNSPC. Further insight into the effect of selective response is important to assess associations between variables more precisely.

Maternal B vitamin intake during pregnancy and childhood behavioral problems in Japan: The Kyushu Okinawa Maternal and Child Health Study.

Objectives: The current prebirth cohort study investigated the relationship between maternal B vitamin intake during pregnancy and behavioral problems in Japanese children aged 5 years. Methods: Subjects were 1199 mother-child pairs. Dietary intake was assessed using a diet history questionnaire. Emotional problems, conduct problems, hyperactivity problems, peer problems, and low prosocial behavior were examined using the Japanese parent-report version of the Strengths and Difficulties Questionnaire. Adjustment was made for maternal age, gestation at baseline, region of residence, number of children, maternal and paternal education, household income, maternal depressive symptoms, alcohol intake, vitamin B complex supplement use, smoking during pregnancy, child's birth weight, child's sex, breastfeeding duration, and smoking in the household during the first year of life. Results: Maternal folate intake during pregnancy was independently inversely associated with childhood low prosocial behavior: the adjusted odds ratio (OR) (95% confidence interval [CI], P for trend) between extreme quartiles was 0.55 (0.37-0.80, 0.0002). Maternal vitamin B6 intake during pregnancy was independently inversely related to childhood hyperactivity problems and low prosocial behavior: the adjusted ORs (95% CIs, P for trend) between extreme quartiles were 0.57 (0.34-0.94, 0.01) and 0.58 (0.40-0.85, 0.0009), respectively. Maternal vitamin B2 intake during pregnancy was independently inversely associated with childhood emotional problems: the adjusted OR (95% CI, P for trend) between extreme quartiles was 0.58 (0.33-0.99, 0.11). Conclusions: Maternal intake of folate, vitamin B6, and vitamin B2 during pregnancy may be protective against childhood low prosocial behavior, hyperactivity problems and low prosocial behavior, and emotional problems, respectively.

Maternal caffeine intake in pregnancy is inversely related to childhood peer problems in Japan: The Kyushu Okinawa Maternal and Child Health Study.

Objectives: The present prebirth cohort study examined the association between maternal caffeine consumption during pregnancy and behavioral problems in Japanese children aged 5 years. Methods: Subjects were 1199 mother-child pairs. Dietary intake was assessed using a diet history questionnaire. Emotional problems, conduct problems, hyperactivity problems, and peer problems were assessed using the Japanese parent-report version of the Strengths and Difficulties Questionnaire. Adjustment was made for maternal age, gestation at baseline, region of residence at baseline, number of children at baseline, maternal and paternal education, household income, maternal depressive symptoms during pregnancy, maternal alcohol intake during pregnancy, maternal smoking during pregnancy, child's birth weight, child's sex, breastfeeding duration, and smoking in the household during the first year of life. Results: The contributors of caffeine in the diet during pregnancy were Japanese and Chinese tea (74.8%), coffee (13.0%), black tea (4.4%), confectionaries (4.0%), and soft drinks (3.7%). Higher maternal caffeine consumption during pregnancy was independently associated with a reduced risk of peer problems in the children: the adjusted odds ratios (95% confidence intervals) in the first, second, third, and fourth quartiles of maternal caffeine consumption during pregnancy were 1 (reference), 0.61 (0.35-1.06), 0.52 (0.29-0.91), and 0.51 (0.28-0.91), respectively (P for trend = 0.01). Maternal caffeine intake during pregnancy was not evidently related to the risk of emotional problems, conduct problems, or hyperactivity problems in the children. Conclusions: Maternal caffeine consumption, mainly from Japanese and Chinese tea, during pregnancy may be preventive against peer problems in Japanese children.

Hardness of the habitual diet and its relationship with cognitive function among 70-year-old Japanese elderly: Findings from the SONIC Study.

BACKGROUND: There is increasing evidence of causal links between poor mastication and cognitive impairment, but possible effects of dietary hardness, which clearly affects mastication, on cognitive function are unknown. OBJECTIVE: We investigated the hypothesis that hardness of the habitual diet would be associated with cognitive function among older Japanese adults. METHODS: The subjects of this cross-sectional study were 635 Japanese community-dwelling people aged 69-71 years. The masticatory muscle activity required for the habitual diet was used to determine dietary hardness. Consumption of 38 foods was assessed by a validated, brief-type, self-administered diet history questionnaire. A published database was then used to estimate the masticatory muscle activity involved in the ingestion of these foods. The Japanese version of the Montreal Cognitive Assessment (MoCA-J) was used for the measurement of cognitive function. RESULTS: The principal contributors to dietary hardness were cooked rice (28.0%), green leafy vegetables (5.1%), dried fish (4.9%), and pork and beef (4.6%). There was a positive association between dietary hardness and MoCA-J score that was robust to adjustment for potential confounders (MoCA-J score per 100-unit increase in dietary hardness: ß = 0.83 [95% CI: 0.08, 1.59], P = 0.03). These results did not change materially even after exclusion of subjects who reported substantial changes in their diet for any reason (ß = 0.94 [95% CI: 0.02, 1.86], P = 0.04). CONCLUSION: This preliminary cross-sectional study suggests that dietary hardness might have a beneficial effect on cognitive function in older Japanese people. Further prospective studies with more accurate measurements are needed to confirm this finding.

Soy isoflavone intake and prevalence of depressive symptoms during pregnancy in Japan: baseline data from the Kyushu Okinawa Maternal and Child Health Study.

OBJECTIVE: Several observational studies and trials examined the relationship between isoflavones or soybeans and depressive symptoms among peri- and postmenopausal women. We cross-sectionally evaluated the associations between intake of soy products and isoflavones and depressive symptoms during pregnancy in Japan. METHODS: Study subjects were 1745 pregnant women. Dietary intake during the preceding month was assessed using a self-administered diet history questionnaire. Depressive symptoms were defined by a score of 16 or over in the Center for Epidemiologic Studies Depression Scale. RESULTS: Higher intake of total soy products, tofu, tofu products, fermented soybeans, boiled soybeans, miso soup, and isoflavones was independently related to a lower prevalence of depressive symptoms during pregnancy: The adjusted prevalence ratios (95 % confidence intervals, P for trend) between extreme quartiles were 0.63 (0.47-0.85, 0.002), 0.72 (0.54-0.96, 0.007), 0.74 (0.56-0.98, 0.04), 0.57 (0.42-0.76, <0.0001), 0.73 (0.55-0.98, 0.03), 0.65 (0.49-0.87, 0.003), and 0.63 (0.46-0.86, 0.002), respectively. A significant positive exposure-response relationship was found between miso intake and depressive symptoms during pregnancy. No material relationship was observed between soymilk intake and depressive symptoms during pregnancy. CONCLUSIONS: Our study is the first to show independent inverse relationships between intake of total soy products, tofu, tofu products, fermented soybeans, boiled soybeans, miso soup, and isoflavones and depressive symptoms during pregnancy.

Lack of a meaningful association between dietary patterns and in vitro fertilization outcome among Japanese women.

PURPOSE: The purpose of this study was to examine whether preconception maternal dietary pattern is associated with in vitro fertilization (IVF) outcome among Japanese women. METHODS: This prospective study included 140 Japanese women who underwent conventional-IVF/intracytoplasmic sperm injection. The patients' diets during the previous month before egg retrieval were assessed with validated brief-type self-administered diet history questionnaire. Dietary patterns from 33 predefined food groups [energy-adjusted food (g/1000 kcal)] were extracted by factor analysis. The primary outcome measure was clinical pregnancy rate after IVF. RESULTS: Thirty-six women had confirmed clinical pregnancy. Three dietary patterns were identified: "Vegetable and seafood," "Western," and "Rice and miso soup." The "Vegetables and seafood" dietary pattern (high intakes of green and other vegetables, mushrooms, seasoning, fish, soy products, chicken, and potatoes) was not associated with clinical pregnancy ([odds ratio per one-quartile increase in dietary pattern: 0.94 (95% confidence interval: 0.67-1.32), P = 0.73]. This relationship was unaltered after controlling for potential confounders. Furthermore, no association was seen between the other two dietary patterns and clinical pregnancy. CONCLUSIONS: The three maternal preconception dietary patterns identified revealed no meaningful association with IVF outcome in Japanese women. Further studies in various populations with different dietary patterns are needed to confirm these findings.

Energy density of the diets of Japanese adults in relation to food and nutrient intake and general and abdominal obesity: a cross-sectional analysis from the 2012 National Health and Nutrition Survey, Japan.

The associations of dietary energy density with dietary intake and obesity have been largely unexplored in non-Western populations. The present cross-sectional study examined the associations using data from the 2012 National Health and Nutrition Survey, Japan. Dietary intake was assessed using a 1-d semi-weighed dietary record in 15 618 Japanese adults aged ≥20 years. Mean dietary energy density (calculated on the basis of foods only) was 5·98 (sd 1·20) kJ/g in men and 5·72 (sd 1·16) kJ/g in women. Dietary energy density was positively associated with intakes of bread, noodles (only men), meat, fats and oils, and sugar and confectionery but inversely with intakes of white rice (only men), potatoes, pulses, vegetables, fruits, and fish and shellfish. For nutrient intake, dietary energy density was positively associated with total fat and SFA but inversely associated with all other nutrients examined such as protein, carbohydrate, alcohol (only women), dietary fibre, and several vitamins and minerals, including Na. After adjustment for potential confounding factors, dietary energy density was positively associated with abdominal obesity (waist circumference ≥80 cm) in women (adjusted prevalence ratio between the extreme tertiles 1·07; 95 % CI 1·02, 1·12; P for trend=0·003). Dietary energy density was also positively but non-significantly associated with general obesity (BMI≥25 kg/m2) in women (P for trend=0·08). There were no such associations in men. In conclusion, lower energy density of the diets of Japanese adults was associated with favourable food and nutrient intake patterns, except for higher Na, and, in only women, a lower prevalence of abdominal obesity.

Association between dietary patterns and cognitive function among 70-year-old Japanese elderly: a cross-sectional analysis of the SONIC study.

BACKGROUND: An increasing number of studies in Western countries have shown that healthy dietary patterns may have a protective effect against cognitive decline and dementia. However, information on this relationship among non-Western populations with different cultural settings is extremely limited. We aim to examine the relationship between dietary patterns and cognitive function among older Japanese people. METHODS: This cross-sectional study included 635 community-dwelling people aged 69-71 years who participated in the prospective cohort study titled Septuagenarians, Octogenarians, Nonagenarians Investigation with Centenarians (SONIC). Diet was assessed over a one-month period with a validated, brief-type, self-administered diet history questionnaire. Dietary patterns from thirty-three predefined food groups [energy-adjusted food (g/d)] were extracted by factor analysis. Cognitive function was assessed using the Japanese version of the Montreal Cognitive Assessment (MoCA-J). Multivariate regression analysis was performed to examine the relationship between dietary patterns and cognitive function. RESULTS: Three dietary patterns were identified: the 'Plant foods and fish', 'Rice and miso soup', and 'Animal food' patterns. The 'Plant foods and fish' pattern, characterized by high intakes of green and other vegetables, soy products, seaweeds, mushrooms, potatoes, fruit, fish, and green tea, was significantly associated with a higher MoCA-J score [MoCA-J score per one-quartile increase in dietary pattern: ß = 0.56 (95% CI: 0.33, 0.79), P for trend <0.001]. This association was still evident after adjustment for potential confounding factors [ß = 0.41 (95% CI: 0.17, 0.65), P for trend <0.001]. In contrast, neither the 'Rice and miso soup' nor the 'Animal food' pattern was related to cognitive function. To confirm the possibility of reverse causation we also conducted a sensitivity analysis excluding 186 subjects who reported substantial changes in their diet for any reason, but the results did not change materially. CONCLUSION: This preliminary cross-sectional study suggests that a diet with high intakes of vegetables, soy products, fruit, and fish may have a beneficial effect on cognitive function in older Japanese people. Further prospective studies are needed to confirm this finding.

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.