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.

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.

Relationship between the number of teeth, occlusal force, occlusal contact area, and dietary hardness in older Japanese adults: The SONIC study.

PURPOSE: Individuals with impaired masticatory function tend to prefer soft foods, which results in decreased masticatory muscle activity. This study examined the association between the oral condition (number of teeth, occlusal force, and occlusal contact area) and dietary hardness using a daily dietary questionnaire. METHODS: This cross-sectional study evaluated 1841 participants aged 69-71 and 79-81 years. Registered dentists examined the number of teeth, occlusal force, and occlusal contact area. Dietary hardness was defined as the estimated masticatory muscle activity required for a habitual diet. Habitual diet during the preceding month was assessed using a brief self-administered diet history questionnaire. Confounding factors, such as age, sex, socioeconomic status, smoking habits, history of chronic diseases (hypertension, hyperlipidemia, and diabetes), and cognitive function were also evaluated. Multivariate linear regression analyses were performed to assess the association between dietary hardness and each oral condition. RESULTS: Occlusal force (standardized regression coefficients [ß]=0.08, P < 0.01) and occlusal contact area (ß=0.06, P < 0.01) were significantly associated with dietary hardness after adjusting for the confounding factors. Number of teeth was not significantly associated with dietary hardness. In addition, the associations between dietary hardness, sex, and a history of diabetes were stronger than those between dietary hardness and oral factors. CONCLUSIONS: Occlusal force and contact area were significantly associated with dietary hardness as estimated from the masticatory muscle activity using a daily diet questionnaire.

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.

Periconceptional maternal diet quality influences blood heavy metal concentrations and their effect on low birth weight: the Japan Environment and Children's Study.

BACKGROUND: Both poor maternal nutrition and toxic heavy metal exposure influence foetal growth and development. However, whether consumption of a variety of healthy foods modifies the association between prenatal heavy metal exposure and foetal growth is unknown. OBJECTIVE: We examined whether long-term maternal diet quality in periconception modifies the associations between maternal circulating concentrations of heavy metals and foetal growth. DESIGN: Data of 72,317 Japanese women who delivered singleton infants was extracted from the Japan Environment and Children's Study. Maternal diet over a 1-year before the first trimester of pregnancy was assessed using a validated food frequency questionnaire, and overall diet quality was determined using the balanced diet score based on the Japanese Food Guide Spinning Top. Maternal whole-blood concentrations of mercury (Hg), lead (Pb) and cadmium (Cd) were measured during the second/third trimester of pregnancy. Bayesian inference of multiple linear regression analysis was performed to evaluate the relationships between maternal diet quality and the blood concentrations of heavy metals; Bayesian logistic regression was used to analyse the risk of low birth weight (LBW; <2,500 g). RESULTS: After controlling for confounders, a high maternal balanced diet score was associated with low concentrations of blood Pb and Cd and high Hg. While all heavy metals assessed were positively associated with LBW risk, a higher maternal balanced diet score was negatively associated with LBW risk. A high-quality maternal diet attenuated the effect of Pb on LBW, an effect that was more marked at high blood Pb concentrations. CONCLUSION: A high-quality, 'well-balanced' diet prior to conception may reduce exposure to some heavy metals and mitigate the elevated risk of LBW associated with prenatal Pb exposure in Japanese mother-child pairs.

Maternal Consumption of Dairy Products during Pregnancy Is Associated with Decreased Risk of Emotional Problems in 5-Year-Olds: The Kyushu Okinawa Maternal and Child Health Study.

Milk is a good source of fats, minerals, and vitamins. The present prebirth cohort study examined the association between maternal dairy product intake during pregnancy and the risk of childhood behavioral problems in 5-year-old Japanese children. 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 non-dietary confounders and potentially related dietary factors. A significant inverse exposure-response association was observed between maternal total dairy intake during pregnancy and the risk of childhood emotional problems (adjusted odds ratio [OR] between extreme quartiles, 0.62; 95% confidence interval [CI]: 0.36-1.03, p for trend, 0.04). The greater maternal consumption of cow's milk, but not yogurt or cheese, during pregnancy was independently related to a reduced risk of emotional problems in children (adjusted OR between extreme quartiles, 0.41; 95% CI: 0.23-0.70, p for trend, 0.003). Higher maternal consumption levels of total dairy products, especially cow's milk, during pregnancy may be associated with a decreased risk of emotional problems in 5-year-old children.

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 calcium intake during pregnancy and childhood blood pressure: the Kyushu Okinawa Maternal and Child Health Study.

PURPOSE: Evidence regarding the relationship between maternal calcium intake during pregnancy and childhood blood pressure is limited and inconsistent. The present prebirth cohort study examined this issue in Japanese children aged 6 years. METHODS: Subjects were 854 mother-child pairs. Maternal intake during pregnancy was assessed with a validated diet history questionnaire. A research technician measured systolic and diastolic blood pressures at home in children aged 6 years using an electronic sphygmomanometer. Analysis of covariance was used to calculate adjusted means of systolic and diastolic blood pressures according to maternal calcium intake during pregnancy. RESULTS: Maternal calcium intake during pregnancy was not related to systolic blood pressure in children. On the other hand, compared with children of mothers whose calcium intake during pregnancy was in the lowest quartile, those of mothers whose calcium intake during pregnancy was in the highest quartile had 2.8 mmHg lower adjusted mean diastolic blood pressure (95% confidence interval: 0.3-5.3 mmHg, P for trend = .009). CONCLUSIONS: Higher maternal calcium intake during pregnancy may be associated with a decrease in diastolic, but not systolic, blood pressure in Japanese children aged 6 years.

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.

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.

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.

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.

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.

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 consumption of vegetables, fruit, and antioxidants during pregnancy and risk for childhood behavioral problems.

OBJECTIVE: The aim of this pre-birth cohort study was to examine the associations between maternal intake of vegetables, fruit, and antioxidants during pregnancy and behavioral problems in Japanese children 5 y of age. METHODS: Participants were 1199 mother-child pairs. Dietary intake was assessed using a diet history questionnaire. Emotional, conduct, hyperactivity, and peer problems, as well as low prosocial behavior were assessed using the parent 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 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 child's first year of life. RESULTS: Maternal intake of total vegetables and green and yellow vegetables during pregnancy was independently inversely associated with childhood low prosocial behavior. Maternal intake of other vegetables during pregnancy was independently inversely related to childhood hyperactivity problems and low prosocial behavior. Maternal intake of fruit and apples during pregnancy was independently inversely related to childhood hyperactivity problems. Maternal intake of citrus fruits during pregnancy was independently inversely related to childhood emotional, conduct, and hyperactivity problems. Maternal vitamin C intake during pregnancy was independently inversely associated with childhood conduct and hyperactivity problems and low prosocial behavior. CONCLUSIONS: Maternal intake of vegetables, fruit, and vitamin C during pregnancy may be preventive against any of the behavioral problems assessed here except for peer problems in Japanese children 5 y of age.

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.

Relationship between oral stereognostic ability and dietary intake in older Japanese adults with complete dentures.

PURPOSE: Oral stereognostic ability (OSA) is a useful indicator of oral perception to recognize food characteristics during mastication. Previous studies have shown associations between dietary intake and oral health status, such as taste perception. However, the effect of oral sensory ability on dietary intake is unclear. The purpose of this study was to investigate the association between oral sensory ability and dietary intake in older Japanese complete denture wearers. METHODS: This cross-sectional study included 164 participants aged 69-71 or 79-81years old, wearing both maxillary and mandibular complete dentures. OSA test was used to evaluate oral tactile perception. Diet during the preceding month was assessed using a self-administered diet history questionnaire. Multivariable linear regression analysis was conducted to assess the association between OSA score and food and nutrient intake after adjusting for age, sex, socioeconomic factors, and occlusal force. RESULTS: The bivariate analysis showed that OSA score was significantly and positively correlated with intake of green and yellow vegetables and negatively correlated with intake of cereals among examined foods. OSA score was also positively correlated with intake of vitamins A, B2, and C and α-tocopherol (as a substitute for vitamin E) among examined nutrients. After adjusting for age, sex, socioeconomic factors, and occlusal force, OSA score remained significantly associated with intake of green and yellow vegetables and α-tocopherol. CONCLUSIONS: OSA was significantly associated with intake of green and yellow vegetables in older complete denture wearers.

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.