Associations between Exposure to Tobacco Smoke and Behavioral Problems in Preschool Japanese Children.

Background: A few studies related to pediatric behavior have measured secondhand smoke exposure in children using valid objective biochemical markers. We aimed at investigating the associations between current and cumulative exposure to tobacco smoke, measured both subjectively and objectively, and behavioral problems in children. Methods: Subjects were 437 Japanese children, aged 3-6 years in 2006. Exposure to tobacco smoke was evaluated from a parent-administered questionnaire and urinary cotinine concentrations. The cotinine concentrations were measured using first-void morning urine by liquid chromatography-tandem mass spectrometry. Children's behaviors were assessed by the parent-completed Strengths and Difficulties Questionnaire. Results: After multiple adjustments for covariates, higher total difficulty scores of children were significantly associated with the larger number of cigarettes parents smoke, more smokers among cohabiters, and more pack-years of exposure to tobacco smoke from parents and cohabiters. The total difficulty scores were 8.72, 9.09, and 10.52, respectively, for children in the low, middle, and high tertiles of creatinine-corrected cotinine concentrations in urine (p=0.002, trend p=0.005). There was no substantial sex difference in the positive associations between passive smoking and the SDQ scores. Conclusions: Exposure to tobacco smoke in early childhood may be involved in the development of pediatric behavioral problems. The importance of reducing the exposure of children to tobacco smoke, particularly in the home, was further emphasized for the prevention of psychological and behavioral problems in childhood.

Associations of Cell Phone Use and Screen Viewing with Overweight in Children.

Background: Effects of using mobile devices on childhood obesity have not been well studied. We aimed to ascertain whether cell phone use and screen viewing are associated with excess body weight in a cross-sectional study of Japanese school children. Methods: Subjects were 3141 students, ages 6 to 7 years, who participated in the Hekinan Children's Study conducted during 2011-2015. Participants were asked to submit a parent-administered questionnaire on child and parent demographics, health status, and lifestyles, including cell phone use and screen time. Heights and weights were measured at the schools. Being overweight was defined according to the cutoff point for children specified by the Extended International Obesity Task Force. Among 2596 analytic children, the odds ratios (ORs) for being overweight were estimated according to cell phone use, time spent watching television, and time spent on games and computers using the logistic regression models. Analyses were conducted after adjustments for potential confounders, including dietary intake, physical activities, sleep duration, and quality of sleep. Results: After multivariate adjustments, cell phone users were found to have an OR of 1.74 for being overweight compared with nonusers. Cell phone use of longer duration was associated with higher risk of being overweight (trend p = 0.018). Time spent watching television was positively associated with the risk of being overweight (trend p = 0.003). Conclusions: Just as earlier studies have shown for television viewing, cell phone use might be a risk factor related to being overweight among children.

Dietary Soy Intake Is Inversely Associated with Risk of Type 2 Diabetes in Japanese Women but Not in Men.

BACKGROUND: Whole soy foods, as well as their components, including protein and isoflavones, have garnered attention because they may have beneficial effects against diabetes. OBJECTIVES: We examined associations between the intake of soy foods, soy protein, and soy isoflavones and the risk of diabetes in the Japanese population. METHODS: This prospective cohort study included 13,521 residents (5883 men and 7638 women; 35-69 y old) of Takayama City, Japan. The subjects responded to a self-administered baseline questionnaire in 1992 and to a follow-up questionnaire seeking information about diabetes in 2002. Their mean ± SD body mass index was 22.6 ± 2.6 kg/m2 (men) and 22.1 ± 2.7 (women). The intakes of total soy foods, fried soy foods, nonfried soy foods, soy protein, and soy isoflavones were estimated through the use of a validated food-frequency questionnaire administered in 1992. Associations between soy intake and the risk of diabetes were evaluated through the use of Cox proportional hazards models incorporating age, education level, physical activity, smoking status, alcohol consumption, history of hypertension, use of vitamin supplements, menopausal status, and dietary factors including glycemic load, total energy, total fat, meat, fruit, vegetables, and coffee. RESULTS: During a 10-y follow-up, 438 participants reported physician-diagnosed diabetes. Women in the highest tertile of intakes of total soy foods, fried soy foods, nonfried soy foods, soy protein, and soy isoflavone had significantly lower HRs, after controlling for covariates, than those with the lowest intakes. For example, HRs were 0.45 (95% CI: 0.30, 0.68; P-trend <0.001) for total soy food intake. In men, there were no significant associations between soy intake and the risk of diabetes. CONCLUSIONS: These results suggest that a high soy intake may be associated with a lower risk of diabetes in Japanese women.

Association between exposure to household smoking and dental caries in preschool children: a cross-sectional study.

BACKGROUND: We aimed to examine the association of exposure to environmental tobacco smoke with dental caries among preschool children. Exposure to environmental tobacco smoke was assessed in terms of urinary cotinine concentrations and pack-years of exposure to smoking by parents and other family members at home. METHODS: This cross-sectional study included 405 preschool children aged 3-6 years from two preschools in Japan in 2006. Information on the smoking habits of family members living with the child was obtained from parent-administered questionnaires. Dental examination was conducted to assess dental caries, that is, decayed and/or filled teeth. Urinary cotinine levels were measured using first-void morning urine samples. RESULTS: Overall, 31.1% of the children had dental caries, and 29.5% had decayed teeth. Exposure to current maternal and paternal smoking was positively associated with the presence of dental caries after controlling for covariates. More than three pack-years of exposure to maternal smoking and more than five pack-years of exposure to smoking by all family members were significantly associated with the presence of dental caries as compared with no exposure (odds ratio [OR] = 5.55, 95% confidence interval [CI] = 2.17-14.22, P for trend < 0.001 and OR = 2.00, 95% CI = 1.12-3.58, P for trend = 0.004, respectively). These exposure variables were similarly associated with the presence of decayed teeth (OR = 2.92, 95% CI = 1.23-6.96, P for trend = 0.01 and OR = 1.75, 95% CI = 0.96-3.20, P for trend = 0.03, respectively). As compared with lowest tertile of the urinary cotinine level, the highest tertile of the urinary cotinine level was significantly associated with the presence of dental caries as well as decayed teeth; the ORs for the highest vs. lowest tertile of urinary cotinine levels were 3.10 (95% CI = 1.71-5.63, P for trend = 0.012) and 2.02 (95% CI = 1.10-3.70, P for trend = 0.10), respectively. CONCLUSIONS: These data suggest that exposure to tobacco smoke may have a dose-dependent influence on the development of caries.

The Hekinan Children's Study: Design and Profile of Participants at Baseline.

BACKGROUND: The early life environment is now recognized as a key factor contributing to susceptibility to certain diseases in later life. METHODS: We initiated a cohort study among school children in 2011 to primarily investigate the associations between lifestyle and environmental factors and some surrogate markers of chronic diseases, such as cardiometabolic risk factors (ie, obesity, high blood pressure, high blood glucose, insulin, or lipids) and cancer risk factors (ie, height and age at menarche). A baseline questionnaire asked for information, including demographic variables, medical history and use of medication, dietary habits, physical activity, sleep habits, and behavioral and emotional problems of children. Follow-up surveys are planned for the fourth grade of elementary school and the first grade of junior high school. At these follow-up surveys, fasting blood samples will be obtained to measure cardiometabolic markers. We also checked the validity of a food frequency questionnaire, which was originally created for 6-year-olds but was modified for use in older children. RESULTS: A total of 3,141 first-year students at elementary schools in Hekinan City, Aichi Prefecture, participated in the study. The response rate was 87.4%. The means of age and body mass index were 6.99 (standard deviation, 0.28) years and 15.3 (standard deviation, 1.7) kg/m2, respectively, in the 3,067 Japanese children (1,639 boys and 1,428 girls). CONCLUSIONS: This cohort will reveal determinants of cardiometabolic risk factors and cancer risk factors during childhood.

Intake of starch and sugars and total and cause-specific mortality in a Japanese community: the Takayama Study.

Studies on the intake of different types of carbohydrates and long-term mortality are sparse. We examined the association of starch, total and each type of sugar and free sugars with the risk of total and cause-specific mortality in a cohort of the general population in Japan. Study subjects were 29 079 residents from the Takayama Study, Japan, who responded to a self-administered questionnaire in 1992. Diet was assessed by a validated FFQ at the baseline. Mortality was ascertained during 16 years of follow-up. We noted 2901 deaths (974 cancer related and 775 cardiovascular related) in men and 2438 death (646 cancer related and 903 cardiovascular related) in women. In men, intake of starch was inversely associated with total mortality after controlling for covariates (hazard ratio (HR) for the highest quartile v. lowest quartile: 0·71; 95 % CI 0·60, 0·84; Ptrend < 0·001). Intakes of total sugars, glucose, fructose, sucrose, maltose and free and naturally occurring sugars were significantly positively associated with total mortality in men (HR for the highest v. lowest quartile of total sugar: 1·27; 95 % CI 1·12, 1·45; Ptrend < 0·0001). Similar relations were observed for cardiovascular mortality and non-cancer, non-cardiovascular mortality in men. In women, there was no significant association between any type of carbohydrates and mortality except that intake of free sugars was significantly positively associated with total and non-cancer, non-cardiovascular mortality. Data suggest that the high intake of starch reduces mortality, whereas the high intake of sugars, including glucose, fructose and sucrose, increases mortality in Japanese men.

Cedar Pollinosis and Mortality: A Population-Based Prospective Cohort Study in Japan.

BACKGROUND: Cedar pollinosis is one of the most prevalent forms of seasonal allergic reaction in Japan. Only one prospective study has examined the association between cedar pollinosis and mortality. Using a symptom-based questionnaire on cedar pollinosis, we investigated the association of cedar pollinosis with all-cause and cause-specific mortality. METHODS: Data came from the Takayama Study, which recruited residents aged ≥35 years in 1992 from Takayama city in Gifu Prefecture, Japan. The current study used information on cedar pollinosis that was obtained from the second survey in 2002. A total of 12,471 persons who were 45-80 years old and had no history of cancer, coronary heart disease, or stroke responded to a questionnaire asking about four symptoms related to cedar pollinosis. Mortality and migration data were obtained throughout the follow-up period up to March 2013. Cox proportional hazard models were used to examine the relation between cedar pollinosis and mortality. RESULTS: A total of 1,276 persons died during follow-up period. Among these, there were 504 neoplasm, 278 cardiovascular, and 181 respiratory deaths. After adjusting for potential confounders, cedar pollinosis was associated with significantly lower all-cause mortality (hazard ratio [HR] 0.79; 95% confidence interval [CI], 0.65-0.95) and respiratory mortality (HR 0.38; 95% CI, 0.18-0.82). There was no significant association between cedar pollinosis and mortality due to neoplasm or cardiovascular disease. CONCLUSIONS: We found an inverse association between cedar pollinosis and the risk of all-cause and respiratory mortality. Further research is needed to elucidate the association between cedar pollinosis and mortality.

Maternal Acrylamide Intake during Pregnancy and Sex Hormone Levels in Maternal and Umbilical Cord Blood and Birth Size of Offspring.

Exposure to acrylamide during pregnancy may disturb pregnancy hormones and the growth of the fetus. The present study aimed to examine the association of maternal acrylamide intake with maternal and cord sex hormone levels during pregnancy and at birth and birth size of offspring. The study subjects were 204 pregnant Japanese women and their newborn girls. Intake of acrylamide was assessed based on 5-day diet records at approximately the 29th week of pregnancy. The concentrations of estradiol, estriol, and testosterone were measured in maternal serum at the 29th weeks of pregnancy and at delivery and umbilical cord blood at delivery. Birth weight, length, and head circumference were measured at the delivery. After controlling for covariates, higher intake of acrylamide was significantly positively associated with higher level of umbilical cord estradiol at the delivery (p for trend = .01), but not with any hormone levels measured in maternal blood. A positive association between acrylamide intake and head circumference was of borderline significance (p for trend = .06). Overall, there were no consistent associations between maternal acrylamide intake and sex hormone levels during pregnancy. However, as this is the first study to examine these associations, additional studies are needed.

Coffee, Green Tea, and Caffeine Intake and Liver Cancer Risk: A Prospective Cohort Study.

We aimed to investigate whether coffee, green tea, and caffeine intake are associated with liver cancer risk, using data of a prospective cohort study. This study included 30,824 participants (14,240 men and 16,584 women) aged 35 years or older in the Takayama study, which was launched on September 1, 1992. The consumption frequencies of coffee and green tea were assessed using a self-administered questionnaire. Caffeine intake was estimated from the consumption frequencies of caffeine-containing beverages and foods and their caffeine content per serving. The incidence of liver cancer was confirmed using regional population-based cancer registries. During the follow-up period of 16 years, a total of 172 participants developed liver cancer. The adjusted hazard ratios and 95% confidence intervals (CIs) in relation to coffee consumption were 0.65 (95% CI: 0.46-0.93) for less than once per day, 0.63 (95% CI: 0.39-1.02) for once per day, and 0.40 (95% CI: 0.20-0.79) for twice per day or more, compared with nondrinkers. No associations with green tea, black tea and caffeine intake were observed. The present study confirmed that coffee consumption significantly reduces liver cancer risk and raises the possibility that caffeine intake might not account for the association.

Soy Isoflavone Intake and Bladder Cancer Risk in Japan: From the Takayama Study.

Background: There is growing evidence suggesting that soy isoflavones play a protective role in the development of cancer. However, few epidemiological studies have investigated the association between soy isoflavone intake and bladder cancer.Methods: We evaluated the associations of soy and isoflavone intakes with bladder cancer incidence in a population-based prospective study in Japan. Subjects were 14,233 men and 16,584 women age 35 years or older in September 1992. Soy and isoflavone intakes were assessed via a validated food-frequency questionnaire, while controlling for total energy intake. Cancer incidence was mainly confirmed through regional population-based cancer registries. Bladder cancer was defined as code C67 according to the International Classification of Diseases and Health Related Problems, 10th Revision.Results: During mean follow-up of 13.6 years, 120 men and 41 women had developed bladder cancer. After adjustments for multiple confounders, compared with the lowest quartile of soy food intake, the estimated hazard ratios for the second, third, and highest quartiles of soy food intake were 0.74, 0.52, and 0.55, respectively, in men (P-trend: 0.023). The corresponding values were 0.60, 0.75, and 0.64, respectively, in women (P-trend: 0.43). Similar inverse associations were observed between isoflavone intake and bladder cancer risk.Conclusions: A significant decreased risk of bladder cancer was observed among men who had higher intakes of total soy and isoflavones.Impact: Our finding on the potential benefit of consuming soy foods against bladder cancer is promising and warrants further studies. Cancer Epidemiol Biomarkers Prev; 27(11); 1371-5. ©2018 AACR.

Associations of Acrylamide Intake With Urinary Sex Hormone Levels Among Preschool-Age Japanese Children.

Acrylamide may affect the sex hormone system in the prepubertal period. This study examined the cross-sectional associations between dietary acrylamide intake and sex hormone levels among preschool-age Japanese children. The study was conducted in 2006 among 230 boys and 198 girls aged 3-6 years in Aichi, Japan. Acrylamide intake was assessed using 3-day diet records. Urinary concentrations of estrone, estradiol, testosterone, and androst-5-ene-3ß, 17ß diol (hereafter referred to as androstenediol) were measured by liquid chromatography-electrospray ionization-tandem mass spectrometry. Sex hormone levels were adjusted for urinary creatinine levels. The estimated acrylamide intake was 1.00 µg/kg of body weight per day. After controlling for age and other covariates, acrylamide intake was significantly positively associated with urinary levels of testosterone and androstenediol in boys. On average, boys in the highest quartile of acrylamide intake had 96.9% higher testosterone (95% confidence interval: -1.8, 295; P for trend = 0.048) and 34.5% higher androstenediol levels (95% confidence interval: -5.9, 92.3; P for trend = 0.04) than boys in the lowest quartile. In girls, there were no significant associations between acrylamide intake and the hormones measured. Acrylamide intake may alter androgen metabolism in preschool-age boys. Because this is a first observation, our findings require confirmation in additional studies.

Association of alcohol consumption with the risk of stomach cancer in a Japanese population: a prospective cohort study.

Biological studies have provided confirmation of alcohol-related carcinogenesis in the stomach, but the association between alcohol consumption and the risk of stomach cancer remains controversial. We aimed to investigate whether quantitative alcohol intake is associated with the risk of stomach cancer in a large prospective cohort study among a Japanese population. Study participants included 30 714 participants (14 171 men and 16 543 women) aged 35 years or older, who were enrolled in the Takayama study launched on 1 September 1992. Alcohol consumption was assessed quantitatively using a validated food frequency questionnaire. According to alcohol intake (g/day), male participants were classified into quartile groups: Q1, Q2, Q3, or Q4. Female participants were classified into three groups: nondrinkers, and drinkers below or above the median alcohol level. We estimated the hazard ratios and 95% confidence intervals (CIs) for stomach cancer adjusted for age, smoking, BMI, education, total energy intake, salt intake, physical activity, and medical history of diabetes mellitus for each alcohol intake group using the Cox proportional hazards regression model. By the end of March 2008, a total of 678 participants had been diagnosed with stomach cancer. For men, the multivariate-adjusted HRs of stomach cancer for Q2, Q3, and Q4 relative to Q1 were 1.39 (95% CI: 1.07-1.81), 1.35 (95% CI: 1.02-1.79), and 1.38 (95% CI: 1.02-1.87), respectively. In women, no associations were observed. These data suggest that alcohol consumption could be associated with an increased risk of stomach cancer among Japanese men.

Sleep duration, nightshift work, and the timing of meals and urinary levels of 8-isoprostane and 6-sulfatoxymelatonin in Japanese women.

It has been hypothesized that disruption of circadian rhythms affects human health. Shift work and sleep deprivation are thought to disrupt the normal light-dark cycle, although the disruption due to shiftwork may be dependent on sleep deprivation. Both conditions have been suggested to be associated with an increased risk of cardiometabolic disorders. Non-photic environmental factors, such as the timing of eating, are also thought to regulate circadian rhythm and thus, may have effects on health, but the evidence from human studies is scarce. Oxidative stress is a risk factor of cardiometabolic disorders. Some laboratory studies suggest an involvement of circadian clock genes in the regulation of the redox system. The present study aimed to examine the association of sleeping habits, nightshift work, and the timing of meals with urinary levels of 8-isoprostane, a marker of oxidative stress, and 6-sulfatoxymelatonin, the principal metabolite of melatonin. Study subjects were 542 women who had previously attended a breast cancer mass screening in a community in Japan. Information on bedtimes and wake-up times, history of nightshift work, and the timing of meals was obtained by a self-administered questionnaire. The 8-isoprostane and 6-sulfatoxymelatonin were measured using the first morning void of urine and expressed per mg of creatinine. The geometric mean of 8-isoprostane levels was 12.1% higher in women with ≤6 hours of sleep than that in those with >8 hours of sleep on weekdays, and longer sleep duration on weekdays was significantly associated with lower urinary levels of 8-isoprostane after controlling for covariates (p for trend = 0.04). Women who were currently working the nightshift had a 33.3% higher geometric mean of 8-isoprostane levels than those who were not working nightshift (p = 0.03). Urinary 6-sulfatoxymelatonin levels were unrelated to sleep habits or nightshift work. Women who ate breakfast at irregular times had a 19.8% higher geometric mean of 8-isoprostane levels than those who ate breakfast at a regular time or who did not eat (p = 0.02). Women who ate nighttime snacks at irregular times had a 16.2% higher geometric mean of 8-isoprostane levels than those who did not eat nighttime snacks or who ate nighttime snacks at a regular time (p = 0.003). Among women who ate dinner at a regular time, earlier times for dinner were associated with higher 8-isoprostane and 6-sulfatoxymelatonin levels (p values for trends were 0.01 and 0.02, respectively). However, the times of dinner and nighttime snack are overlapping, and the time of last meal of the day was not associated with 8-isoprostane and 6-sulfatoxymelatonin levels. The time of breakfast or lunch was not associated with these biomarkers among women who ate the meal at regular times. Disturbing the rhythmicity of daily life may be associated with oxidative stress.

Meat consumption and colorectal cancer risk in Japan: The Takayama study.

Compared with the abundant data from Western countries, evidence regarding meat consumption and colorectal cancer is limited in the Japanese population. We evaluated colorectal cancer risk in relation to meat consumption in a population-based prospective cohort study in Japan. Participants were 13 957 men and 16 374 women aged ≥35 years in September 1992. Meat intake, assessed with a validated food frequency questionnaire, was controlled for the total energy intake. The incidence of colorectal cancer was confirmed through regional population-based cancer registries and histological identification from colonoscopy in two main hospitals in the study area. From September 1992 to March 2008, 429 men and 343 women developed colorectal cancer. After adjustments for multiple confounders, a significantly increased relative risk of colorectal cancer was observed in the highest versus lowest quartile of the intake of total and red meat among men; the estimated hazard ratios were 1.36 (95% CI: 1.03, 1.79) for total meat (P for trend = 0.022), and 1.44 (95% CI: 1.10, 1.89) for red meat (P for trend = 0.009). A positive association between processed meat intake and colon cancer risk was also observed in men. There was no significant association between colorectal cancer and meat consumption in women. These results suggest that the intake of red and processed meat increases the risk of colorectal or colon cancer among Japanese men. Abstaining from excessive consumption of meat might be protective against developing colorectal cancer.

Hot-cold foods in diet and all-cause mortality in a Japanese community: the Takayama study.

PURPOSE: In the field of traditional Chinese medicine, foods are grouped as cold or hot, and the balance of hot and cold food intake is considered vital to good health. We aimed to examine prospectively whether hot-cold food intake as well as ratio of hot-to-cold foods is associated with all-cause mortality in a general population. METHODS: A total of 28,356 residents of Takayama City, Japan (response rate: 85.3%, mean age: 54.6 [SD, 12.6] years, male: 45.9%), responded to a food frequency questionnaire in 1992. This questionnaire was used to assess intakes of hot, cold, and neutral foods. Four different lists by Lu, Nishimura, Kuwaki, and Dobashi were used to classify foods as hot, cold, or neutral. RESULTS: During a follow-up of 16 years (loss to follow-up: 6.1%), 5339 deaths were identified. In men, hot food intake was significantly positively associated with the risk of all-cause mortality according to Nishimura's classification and significantly inversely associated with the risk according to Lu's and Dobashi's classifications. In women, hot food intake was inversely associated with the risk only according to Dobashi's classification. CONCLUSIONS: We found no clear and consistent evidence that hot-cold food intake is associated with all-cause mortality in Japanese.

Dietary soy and natto intake and cardiovascular disease mortality in Japanese adults: the Takayama study.

BACKGROUND: Whether soy intake is associated with a decreased risk of cardiovascular disease (CVD) remains unclear. A traditional Japanese soy food, natto, contains a potent fibrinolytic enzyme. However, its relation to CVD has not been studied. OBJECTIVE: We aimed to examine the association of CVD mortality with the intake of natto, soy protein, and soy isoflavones in a population-based cohort study in Japan. DESIGN: The study included 13,355 male and 15,724 female Takayama Study participants aged ≥35 y. At recruitment in 1992, each subject was administered a validated semiquantitative food-frequency questionnaire. Deaths from CVD were ascertained over 16 y. RESULTS: A total of 1678 deaths from CVD including 677 stroke and 308 ischemic heart disease occurred during follow-up. The highest quartile of natto intake compared with the lowest intake was significantly associated with a decreased risk of mortality from total CVD after control for covariates: the HR was 0.75 (95% CI: 0.64, 0.88, P-trend = 0.0004). There were no significant associations between the risk of mortality from total CVD and intakes of total soy protein, total soy isoflavone, and soy protein or soy isoflavone from soy foods other than natto. The highest quartiles of total soy protein and natto intakes were significantly associated with a decreased risk of mortality from total stroke (HR = 0.75, 95% CI: 0.57, 0.99, P-trend = 0.03 and HR = 0.68, 95% CI: 0.52, 0.88, P-trend = 0.0004, respectively). The highest quartile of natto intake was also significantly associated with a decreased risk of mortality from ischemic stroke (HR = 0.67, 95% CI:0.47, 0.95, P-trend = 0.03). CONCLUSION: Data suggest that natto intake may contribute to the reduction of CVD mortality.

Relationship of equol production between children aged 5-7 years and their mothers.

PURPOSE: The factors responsible for the production of isoflavone metabolites have not yet been identified. We aimed to examine the relationships of equol production between mother and child in a birth cohort in Japan. METHODS: Subjects were a part of the participants in a longitudinal study on pregnant women and their offspring. When children were 5-7 years old, mothers and children were asked to reply to a questionnaire on lifestyles and a 3-day child's dietary record. Mothers and children were given a bar-shaped soy snack (Soyjoy®) daily on two consecutive days (soy challenge). The snack contained 14 mg of overall soy isoflavones as the sum of aglycones and the glucosides for mothers and 7.5 mg for children. On the morning of day 0 and 3, they were asked to mail their first-void urines. Urinary isoflavone metabolites of 159 mother-child pairs were measured by a high-performance liquid chromatography method. RESULTS: Equol producers were 35.5 % among mothers and 13.8 % among children. Equol producer status of a child was neither associated with dietary intake nor with urinary levels of daidzein and genistein. After multiple adjustments for potential confounders, the estimated relative risk of equol producer was 2.75 (95 % confidence interval 1.00, 7.52) among children whose mother was an equol producer, compared with children whose mother was a non-producer. CONCLUSION: Child's equol production was associated with the mother's equol producer status. The effects of maternal factors on child's equol production should be studied further.

Dietary magnesium intake and the risk of diabetes in the Japanese community: results from the Takayama study.

PURPOSE: Several experimental studies showed that magnesium intake improved insulin resistance and glucose uptake in diabetes patients. However, epidemiological studies on the association between magnesium intake and diabetes risk have yielded inconsistent results. We investigated whether magnesium intake is related to the risk of developing diabetes in a population-based cohort study in Japan. METHODS: Study subjects were participants in the Takayama study. A total of 13,525 residents in Takayama City, Japan, responded to a self-administered questionnaire in 1992 and to a follow-up questionnaire seeking information about diabetes in 2002. Magnesium and other nutrient intakes were estimated from a validated food frequency questionnaire administered at the baseline. RESULTS: During a follow-up of 10 years, 438 subjects reported diabetes newly diagnosed by physician. Compared with women in the low quartile of magnesium intake, women in the high quartile were at a significantly reduced risk of diabetes (HR 0.50; 95 % CI 0.30-0.84; P-trend 0.005) after adjustments for covariates. In men, there was no association between magnesium intake and the risk of diabetes. CONCLUSION: These results suggest that diets with a high intake of magnesium may decrease the risk of diabetes in women.

Associations of urinary cadmium with circulating sex hormone levels in pre- and postmenopausal Japanese women.

BACKGROUND: Exposure to cadmium has been suspected as a risk factor for breast cancer. The present study examined the associations between urinary cadmium levels and circulating sex hormone levels that are linked to breast cancer risk in healthy women. METHODS: The study subjects were 396 premenopausal Japanese women who had regular menstrual cycles less than 40 days long and 207 postmenopausal Japanese women. Urinary cadmium was measured using spot urine samples. Plasma estradiol, testosterone, and dehydroepiandrosterone sulfate were measured. Additionally, the follicle-stimulating hormone, luteinizing hormone, and sex hormone-binding globulin were measured for premenopausal women. RESULTS: In premenopausal women, the urinary cadmium level either expressed in µg per liter or per g of urine creatinine was significantly inversely associated with total and free testosterone levels after controlling for age, body mass index, smoking status, alcohol intake, and the phase of the menstrual cycle. Total and free testosterone levels were 14.6% and 15.0% lower, respectively, in women in the highest quartile of urinary cadmium per g creatinine in those in the lowest quartile. In postmenopausal women, the urinary cadmium in µg per liter as well as per g creatinine was significantly inversely associated with the estradiol level after controlling for covariates. The estradiol level was 25.8% lower in women in the highest tertile of urinary cadmium per g creatinine than in those in the lowest tertile. CONCLUSIONS: The data suggest inverse associations between urinary cadmium and the plasma estradiol or testosterone level in Japanese women.

Alcohol Intake During Pregnancy and Offspring's Atopic Eczema Risk.

BACKGROUND: Although alcohol consumption has been suggested to have an effect on the immune system, it is unknown whether alcohol consumption has a role in developing allergic diseases. We aimed to examine the associations of total alcohol intake during pregnancy with the risks of childhood asthma and atopic eczema in a birth cohort in Japan. METHODS: Pregnant women were recruited at a maternal clinic from May 2000 to October 2001. The children who were born to these mothers were followed until November 2007. Total alcohol intake, including alcohol as a cooking ingredient, was assessed using 5-day dietary records. Mother reports of physician-diagnosed asthma and atopic eczema were annually obtained from the questionnaires. Asthma assessed by the American Thoracic Society Division of Lung Diseases questionnaire and atopic eczema assessed by International Study of Asthma and Allergies in Childhood questions were also obtained in 2007. A total of 350 children participated in the follow-up survey. RESULTS: Maternal total alcohol intake during pregnancy was associated with increased risks of atopic eczema before age 3. The positive association with atopic eczema was also observed when it was defined as before age 5. In the high versus the low tertile of maternal total alcohol intake, the estimated hazard ratios (HRs) of child's eczema were 1.90 (95% CI: 0.96 to 3.76) before age 3 and 1.74 (95% CI: 0.93 to 3.24) before age 5, respectively. The estimated HRs of child's asthma before age 3 was 1.61 (95% CI: 0.70 to 3.69) in the high versus the low of maternal total alcohol intake and 2.11 (95% CI: 0.93 to 4.81) among children having drinking mothers versus nondrinking mothers in pregnancy, although maternal alcohol intake during pregnancy was not significantly associated with the risk of asthma before age 5. CONCLUSIONS: Alcohol consumption during pregnancy might have an effect on developing atopic eczema in offspring.