Association of dietary fibre intake with subsequent fasting glucose levels and indicators of adiposity in school-age Japanese children.

OBJECTIVE: To evaluate the relationships of fibre intake with subsequent BMI sd-score, waist-to-height ratio and serum fasting glucose levels among school-age Japanese children. DESIGN: This is a prospective study of school-age Japanese children. Participants were followed from 6-7 to 9-10 years of age (follow-up rate: 92·0 %). Fibre intake was assessed using a validated FFQ. Serum fasting glucose was measured by a hexokinase enzymatic method. Using a general linear model, the associations between dietary fibre intake at baseline and BMI sd-score, waist-to-height ratio, and serum levels of fasting glucose at follow-up were evaluated after considering potential confounding factors. SETTING: Public elementary schools in a city in Japan. PARTICIPANTS: A total of 2784 students. RESULTS: The estimated means for fasting glucose at 9-10 years of age were 86·45, 85·68, 85·88 and 85·58 mg/dl in the lowest, second, third and highest quartile of fibre intake at 6-7 years of age, respectively (P = 0·033, trend P = 0·018). Higher fibre intake at 6-7 years of age was associated with lower waist-to-height ratio at 9-10 years of age (trend P = 0·023). The change in fibre intake was inversely associated with concurrent change of BMI sd-score (trend P = 0·044). CONCLUSION: These results suggest that dietary fibre intake may be potentially effective to limit excess weight gain and lower glucose levels during childhood.

Associations of total nut and peanut intakes with all-cause and cause-specific mortality in a Japanese community: the Takayama study.

Numerous epidemiological studies have suggested that nut intake is associated with a reduced risk of mortality. Although diets and lifestyles differ by regions or races/ethnicities, few studies have investigated the associations among non-white, non-Western populations. We evaluated the associations of total nut and peanut intakes with all-cause and cause-specific mortality in a population-based prospective cohort in Japan. Participants (age: ≥35 years at baseline in 1992; n 31 552) were followed up until death or the end of follow-up in 2008. Those with cancer, CHD or stroke at baseline were excluded. Dietary intake was assessed only at baseline by using a validated FFQ. In total, 2901 men died during 183 299 person-years and 2438 women died during 227 054 person-years. The mean intakes of total nuts were 1·8 and 1·4 g/d in men and women, respectively. Although peanut intake accounted for approximately 80 % of the total nut intake, total nut and peanut intakes were inversely associated with all-cause mortality in men after adjusting for all potential confounders. For example, compared with the lowest quartile category, the adjusted hazard ratio (95 % CI) of total nut intake for all-cause mortality in men of the highest quartile category was 0·85 (95 % CI 0·75, 0·96) (Pfor trend = 0·034). Peanut intake was inversely associated with digestive disease mortality in men and CVD mortality in women. Total nut and peanut intakes, even in low amounts, were associated with a reduced risk of mortality particularly in men.

Associations Between Dietary Melatonin Intake and Total and Cause-Specific Mortality Among Japanese Adults in the Takayama Study.

Potential health benefits of melatonin have been suggested. Although melatonin is present in various foods, little is known about the health effects of dietary melatonin intake. We estimated habitual dietary melatonin intake and examined its association with total and cause-specific mortality in a population-based cohort study in Japan. Study subjects included 13,355 men and 15,724 women aged ≥35 years who responded to a self-administered questionnaire in 1992. Their diets were assessed via a food frequency questionnaire at baseline. The melatonin content in various foods on the questionnaire was measured to estimate melatonin intake. Mortality was ascertained during 16 years of follow-up (1992-2008). Hazard ratios (HRs) and 95% confidence intervals (CIs) for total and cause-specific mortality were calculated according to melatonin quartiles. A total of 5,339 deaths occurred during follow-up. Melatonin intake was significantly associated with decreased risks of total mortality, cardiovascular mortality, and noncancer, noncardiovascular mortality after controlling for covariates; HRs for the highest quartile of melatonin intake versus the lowest were 0.90 (95% CI: 0.82, 0.98; P for trend = 0.05), 0.85 (95% CI: 0.72, 0.99; P for trend = 0.10), and 0.77 (95% CI: 0.67, 0.90; P for trend = 0.003), respectively. The data suggest a potential benefit of dietary melatonin with regard to mortality rates.

Dietary Intake of Nε-carboxymethyl-lysine, a Major Advanced Glycation End Product, is Not Associated with Increased Risk of Mortality in Japanese Adults in the Takayama Study.

BACKGROUND: Although endogenous advanced glycation end products (AGEs) have been implicated in the development of various chronic diseases, whether AGEs in foods represent a risk to human health remains unknown. OBJECTIVES: We aimed to estimate the intake of Nε-carboxymethyl-lysine (CML), a major AGE product, using a database of CML contents on LC-MS methods, and to examine CML's association with total and cause-specific mortality in Japanese adults. METHODS: The analysis included 13,355 men and 15,724 women, aged 35 years and older, from the Takayama study. They responded to a self-administered questionnaire in 1992. Their diet, including the CML intake, was assessed using a food-frequency questionnaire at baseline. Mortality was ascertained during 16 years of follow-up. HRs and 95% CIs for mortality were estimated separately for men and women according to CMI quartiles. RESULTS: We noted 2901 deaths in men and 2438 deaths in women during the follow-up. In men, as compared with the lowest quartile of intake, the highest quartile of CML was inversely associated with the risks of both total and non-cancer, non-cardiovascular disease mortality after controlling for covariates [HR = 0.89 (95% CI, 0.79-1.00; P-trend = 0.047) and HR = 0.74 (95% CI, 0.58-0.94; P-trend = 0.03), respectively]. However, stratified analyses showed both inverse and positive associations between CML intake and cause-specific mortality in women, depending on their characteristics. For example, years of education had a modifying effect on both the CML intake and non-cancer, non-cardiovascular disease mortality in women. In men, the associations of CML intake with mortality depended on food sources. CONCLUSIONS: Overall, the present study does not support a positive association between CML intake and mortality in Japanese adults. The potential relevance of the food source of CML to the link between dietary CML and mortality warrants further attention.

High Intake of Free Sugars, Fructose, and Sucrose Is Associated with Weight Gain in Japanese Men.

BACKGROUND: Available evidence for associations between sugar intake and body weight is largely from short-term controlled trials and studies focusing on sugar-sweetened beverages. Studies on long-term weight change related to the intake of types of sugar are thus needed. OBJECTIVE: We examined the associations between weight change and the intake of various types of carbohydrates, including starch, total sugars, and free or naturally occurring sugars and saccharides (i.e., glucose, fructose, sucrose, and lactose), among Japanese men and women. METHODS: This prospective cohort study included 14,971 residents of Takayama City in Japan who were aged 35-69 y at the first survey in 1992 and responded to a self-administrated questionnaire at the second survey in 2002. We excluded those with cancer, coronary artery disease, stroke, or diabetes on the first survey and those with missing information about body weight on both surveys, leaving 13,229 participants for analysis (5879 men and 7350 women). Mean (95% CI) values of 10-y weight change according to types of carbohydrates were estimated using linear regression models with adjustment for total energy intake and other dietary and lifestyle factors. Dietary intake was assessed at the first survey using a validated FFQ. RESULTS: Among men, free sugar intake was associated with weight gain and the estimated means (95% CIs) of weight change were -0.60 (-0.67, -0.54), -0.31 (-0.38, -0.24), -0.12 (-0.19, -0.05), and 0.20 (0.13, 0.27) kg from the first to fourth quartiles (P-trend = 0.002). Moreover, high intakes of sucrose and fructose were associated with weight gain (P-trend: 0.018 for sucrose and 0.001 for fructose). Among women, the intake of any type of carbohydrate was not significantly associated with weight change. CONCLUSIONS: These results suggested that high intakes of free sugars, sucrose, and fructose were associated with long-term weight gain among Japanese men.

Number of Teeth and All-Cause and Cancer Mortality in a Japanese Community: The Takayama Study.

BACKGROUND: The association between the number of teeth and mortality among community-dwelling people has been examined in many epidemiological studies. However, few Japanese studies have included cancer mortality as an endpoint. We prospectively investigated the association between number of remaining teeth and all-cause and cancer mortality in a Japanese community. METHODS: This study included participants in the Takayama Study who were aged 35-70 years old at baseline in 1992. Information on the number of remaining teeth was obtained from 11,273 participants via questionnaire at the second survey in 2002. The response rate was 66.9%. Deaths and their causes were ascertained during 11.8 years of follow-up. RESULTS: A total of 1,098 deaths (435 cancer-related and 235 cardiovascular-related) were identified during the follow-up period. After adjusting for covariates, participants with 0 to 9 teeth were at moderate but significantly increased risk of all-cause mortality (hazard ratio [HR] 1.19; 95% confidence interval [CI], 1.03-1.39) and cancer mortality (HR 1.31; 95% CI, 1.03-1.67) compared to those with 20 or more teeth. With regard to cancer site, a significant association was observed for lung cancer (HR for 0-9 teeth vs. 20 or more teeth, 1.75; 95% CI, 1.08-2.83). This association was somewhat strengthened among never-smokers (HR 3.56; 95% CI, 1.02-12.45). CONCLUSIONS: We observed that a lower number of remaining teeth was significantly associated with increased risk from all-cause and lung cancer mortality. Further studies on the number of teeth and lung and other types of cancer are needed.

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.

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.

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.

Green tea intake and colorectal cancer risk in Japan: the Takayama study.

BACKGROUND: Reportedly, green tea has a preventive effect against colorectal cancer in animal models. Nevertheless, results from epidemiological studies of the association between green tea consumption and colorectal cancer have been inconsistent. We aimed to evaluate colorectal cancer risk in relation to green tea consumption in a population-based prospective cohort study. METHODS: Subjects were 13 957 men and 16 374 women aged ≥35 years in September 1992. The participants' green tea consumption was elicited by administering a food frequency questionnaire. The colorectal cancer incidence was confirmed through regional population-based cancer registries and histological identification from colonoscopy in two main hospitals in the study area. Colorectal cancer was defined as the sum of code C18 (colon cancer) and codes C19 and C20 (rectal cancer) according to ICD-10. RESULTS: Up to March 2008, 429 men and 343 women were diagnosed with colorectal cancer. No significant association was found between green tea consumption and colorectal cancer in men and women, respectively. However, for men, compared with the group of 'none or less than once per day' of green tea consumption, the multiple-adjusted relative risks (95% CIs) for colon cancer were 1.32 (0.90, 1.94), 0.76 (0.57, 1.02), and 0.78 (0.49, 1.22), respectively, in the group of 'once per day,' '2-3 times per day', and 'four times per day or more' (trend P = 0.045). CONCLUSIONS: This study observed no overall significant associations between green tea consumption and colorectal cancer risk, except that there was a weak trend for greater consumption of green tea with decreased risk of male colon cancer.

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.

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.

Associations between coffee consumption and all-cause and cause-specific mortality in a Japanese city: the Takayama study.

OBJECTIVE: Epidemiological studies suggest that coffee consumption is inversely associated with all-cause and cause-specific mortality. Evidence from studies targeting non-white, non-Western populations is still sparse, although coffee is popular and widely consumed in Asian countries. DESIGN: Population-based, prospective cohort study. We used Cox proportional hazards models with adjustment for dietary and lifestyle factors to estimate associations between coffee consumption and all-cause and cause-specific mortality. Dietary intake including coffee consumption was assessed only at baseline using a validated FFQ. SETTING: A Japanese city. PARTICIPANTS: Individuals aged 35 years or older without cancer, CHD and stroke at baseline (n 29 079) and followed from 1992 to 2008. RESULTS: From 410 352 person-years, 5339 deaths were identified (mean follow-up = 14·1 years). Coffee consumption was inversely associated with mortality from all causes and CVD among all participants, but not from cancer. Compared with the category of 'none', the multivariate hazard ratio (95 % CI) for all-cause mortality was 0·93 (0·86, 1·00) for <1 cup/d, 0·84 (0·76, 0·93) for 1 cup/d and 0·81 (0·71, 0·92) for 2-3 cups/d. The multivariate hazard ratio (95 % CI) for cardiovascular mortality were 0·87 (0·77, 0·99) for <1 cup/d, 0·76 (0·63, 0·92) for 1 cup/d and 0·67 (0·50, 0·89) for 2-3 cups/d. Inverse associations were also observed for mortality from other causes, specifically infectious and digestive diseases. CONCLUSION: Drinking coffee, even 1 cup/d, was inversely associated with all-cause mortality and mortality from cardiovascular, infectious and digestive diseases.

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.

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.

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.

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.

Associations of Plasma 25-Hydroxy Vitamin D and Dietary Vitamin D Intake with Insulin Resistance in Healthy Japanese Women.

We investigated the associations of plasma 25-hydroxy vitamin D (25(OH)D) concentration and the dietary intake of vitamin D with insulin resistance in Japanese women. Study participants were 406 Japanese women attended a health examination. They were not taking hormones or medications for diabetes and had no history of cancer, ischemic heart disease, or stroke. Information regarding medical history and lifestyle factors was obtained by a self-administered questionnaire, while hours of sun exposure were determined through interviews. Dietary intake of vitamin D was evaluated using a validated food frequency questionnaire. Fasting plasma glucose and insulin concentrations were measured, and insulin resistance (HOMA-IR) scores were calculated based on homeostasis model assessment. Women with vitamin D deficiency (25(OH)D<20 ng/mL) had significantly higher fasting plasma insulin concentration and HOMA-IR than did the other women. Plasma 25(OH)D concentration was significantly and inversely associated with fasting plasma insulin level and HOMA-IR after controlling for age, season, menopausal status, BMI, smoking status, alcohol intake, physical exercise, and intakes of fat and calcium. Dietary vitamin D intake was not associated with HOMA-IR concentration after adjusting for these covariates and hours of sun exposure. Although significant inverse association between plasma 25(OH)D concentration and HOMA-IR was observed in women with a low BMI, low fat intake, or a high calcium intake, the interaction terms were not statistically significant. Data suggest that plasma vitamin D, but not dietary vitamin D, is inversely associated with fasting plasma insulin concentration and HOMA-IR in non-diabetic Japanese women.

Birth month and mortality in Japan: a population-based prospective cohort study.

Epidemiologic studies investigating the association between birth season and risk of mortality in adulthood are limited and have yielded inconclusive results. We aimed to examine the relationship between birth month and all-cause and cause-specific mortality, after controlling for potential confounders, including lifestyle and medical factors, in a population-based cohort study in Japan. We included 28,884 subjects (13,262 men and 15,622 women) from Takayama City, aged 35 years or older without cancer, stroke, and ischemic heart disease, who were born in Japan at baseline. Participants who were enrolled in 1992 were followed up for over 16 years. Information including place of birth, lifestyles, and medical history was obtained from a baseline questionnaire. We performed a Cox proportional hazards analysis to determine the association between birth month and all-cause and cause-specific mortality after adjusting for potential confounders. During the follow-up period (mean follow-up: 14.1 years), 5,303 deaths (2,881 men and 2,422 women) were identified. After controlling for multiple covariates, it was found that being born in April or June was associated with an increased risk of all-cause mortality compared to being born in January (hazard ratio [HR] 1.138; 95% confidence interval [CI], 1.006-1.288 and HR 1.169; 95% CI, 1.028-1.329, respectively). The HRs for cardiovascular mortality were significantly higher in participants born in March and May (HR 1.285; 95% CI, 1.056-1.565 and HR 1.293; 95% CI, 1.040-1.608, respectively). Our findings indicate that an individual's birth month may be an indicator of the susceptibility to mortality in later life.