Nutritional Adequacy Assessment of the Japanese Diet Using the Number of Dishes Compared to Existing Dietary Diversity Indices: A Cross-Sectional Analysis from the 2012 National Health and Nutrition Survey, Japan.

The Japanese diet has attracted attention as a factor contributing to the Japanese population's longevity. A typical Japanese meal, traditionally called "ichiju-sansai," is composed of various dishes. This study assessed the nutritional adequacy of the Japanese diet using the number of dishes in all meals (NDAM) compared to existing dietary diversity indices (DDIs). This cross-sectional study used data from the 2012 National Health and Nutrition Survey. A total of 25,976 participants aged ≥20 y were included in this study. NDAM was calculated for whole dishes or single foods (except supplements and beverages) from one-day weighted dietary records. The food variety score (FVS), number of foods, dietary diversity score (DDS), and number of food groups are some of the existing DDIs. NDAM had relatively high positive correlation coefficients with potassium, magnesium, and dietary fiber. The partial correlation coefficients with an indicator of the overall nutrient adequacy of NDAM was 0.42 for men and 0.42 for women. It was almost the same as that of the FVS (men: 0.44, women: 0.42) and DDS (men: 0.44, women: 0.43). On the other hand, NDAM, similar to existing DDIs, was also positively correlated with nutrient restriction in both sexes. These findings indicate that the nutrient adequacy of NDAM is similar to that of the existing DDIs. Because of the higher sodium intake and cholesterol intake in higher NDAM and existing DDIs, the effect of higher NDAM on health outcomes must be investigated in future studies.

Coffee and Green Tea Consumption and Cardiovascular Disease Mortality Among People With and Without Hypertension.

Background This study was conducted to examine the impacts of coffee and green tea consumption on cardiovascular disease (CVD) mortality among people with severe hypertension. Methods and Results In the JACC (Japan Collaborative Cohort Study for Evaluation of Cancer Risk), 18 609 participants (6574 men and 12 035 women) aged 40 to 79 years at baseline who completed a lifestyle, diet, and medical history questionnaire, and health examinations, were followed up until 2009. We classified the participants into four blood pressure (BP) categories: optimal and normal BP, high-normal BP, grade 1 hypertension, and grade 2-3 hypertension. A Cox proportional hazard model was used to calculate the multivariable hazard ratios with 95% CIs of CVD mortality. During the 18.9 years of median follow-up, a total of 842 CVD deaths were documented. Coffee consumption was associated with an increased risk of CVD mortality among people with grade 2-3 hypertension; the multivariable hazard ratios (95% CI) of CVD mortality were 0.98 (0.67-1.43) for <1 cup/day, 0.74 (0.37-1.46) for 1 cup/day, and 2.05 (1.17-3.59) for ≥2 cups/day, compared with non-coffee drinkers. Such associations were not found among people with optimal and normal, high-normal BP, and grade 1 hypertension. Green tea consumption was not associated with an increased risk of CVD across any BP categories. Conclusions Heavy coffee consumption was associated with an increased risk of CVD mortality among people with severe hypertension, but not people without hypertension and with grade 1 hypertension. In contrast, green tea consumption was not associated with an increased risk of CVD mortality across all categories of BP.

Association between dietary intake of n-3 polyunsaturated fatty acids and risk of colorectal cancer in the Japanese population: The Japan Collaborative Cohort Study.

BACKGROUND: Epidemiological studies of the dietary intake of specific n-3 polyunsaturated fatty acids (PUFA) and anatomical subsite-specific colorectal cancer (CRC) are limited. We examined the prospective associations of total n-3 PUFA, marine-derived n-3 PUFA [combined eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA)], and alpha-linolenic acid (ALA) as plant-derived n-3 PUFA with the risk of CRC by subsite in the Japan Collaborative Cohort Study. METHODS: The participants completed a self-administered food frequency questionnaire and had no prior history of CRC. Cox proportional hazards model was used to determine the associations between n-3 PUFAs intake and CRC risk overall and by anatomical subsite. RESULTS: During the median 13.8-year follow-up period, 699 of the 42,536 participants aged 40-79 years developed incident CRC. An inverse association was found between dietary ALA intake and the risk of distal colon cancer; the multivariable hazard ratios and 95% confidence intervals for the highest quartiles (Q4) were 0.41 (0.21-0.81; p trend = 0.01) compared with the lowest quartiles (Q1). Marine n-3 PUFA intake was not associated with CRC risk in the overall or anatomical subsite-specific analyses. CONCLUSION: Our findings suggest that higher ALA intake may be beneficial for lowering the risk of distal colon cancer.

Green Tea Consumption and Risk of Depression Symptoms: A Systematic Review and Meta-Analysis of Observational Studies.

This systematic review and meta-analysis aimed to investigate the association between green tea consumption and depression symptom risk, using subgroup analyses concerning study design, geographical region of study, adjustment factors, age, cut-off for the highest consumption category, and depression assessment methods applied. We used PubMed to search for relevant literature. The inclusion criteria were studies that (a) investigated this association as a primary or secondary outcome; (b) published in English; (c) assessed and reported hazard ratios or odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) for depression symptoms, or included sufficient information to allow their calculation; (d) included at least two groups differentiated based on green tea consumption (e.g., high and low); (e) reported the prevalence of depression symptoms in each group; and (f) reported the sample size for each group. Eight articles were found to meet all criteria. The results indicated that high green tea consumption is inversely associated with depression symptoms. The pooled OR was 0.66 (95% CI 0.58-0.74), and significant heterogeneity was not observed. Subgroup analysis showed that study design impacted results (cohort study [one study]: OR=0.29, 95% CI=0.04-2.14; cross-sectional study [seven studies]: OR=0.66, 95% CI=0.59-0.75). These findings suggest that green tea consumption reduces the risk of depression symptoms. This association was also observed in the cohort study included, but the results in which did not reach the significant level. Therefore, further cohort studies are needed to confirm the potential causal relationship in this regard.

Comparison of dimension reduction methods on fatty acids food source study.

Serum fatty acids (FAs) exist in the four lipid fractions of triglycerides (TGs), phospholipids (PLs), cholesteryl esters (CEs) and free fatty acids (FFAs). Total fatty acids (TFAs) indicate the sum of FAs in them. In this study, four statistical analysis methods, which are independent component analysis (ICA), factor analysis, common principal component analysis (CPCA) and principal component analysis (PCA), were conducted to uncover food sources of FAs among the four lipid fractions (CE, FFA, and TG + PL). Among the methods, ICA provided the most suggestive results. To distinguish the animal fat intake from endogenous fatty acids, FFA variables in ICA and factor analysis were studied. ICA provided more distinct suggestions of FA food sources (endogenous, plant oil intake, animal fat intake, and fish oil intake) than factor analysis. Moreover, ICA was discovered as a new approach to distinguish animal FAs from endogenous FAs, which will have an impact on epidemiological studies. In addition, the correlation coefficients between a published dataset of food FA compositions and the loading values obtained in the present ICA study suggested specific foods as serum FA sources. In conclusion, we found that ICA is a useful tool to uncover food sources of serum FAs.

Green Tea and Coffee Consumption and All-Cause Mortality Among Persons With and Without Stroke or Myocardial Infarction.

BACKGROUND AND PURPOSE: The effect of green tea and coffee consumption on mortality among cardiovascular diseases survivors is unknown. We examined the association between green tea and coffee consumption and mortality among persons with and without stroke or myocardial infarction (MI). METHODS: In the Japan Collaborative Cohort Study, 46 213 participants (478 stroke survivors, 1214 MI survivors, and 44 521 persons without a history of stroke or MI), aged 40 to 79 years at baseline (1988-1990), completed a lifestyle, diet, and medical history questionnaire and were followed up regarding mortality until 2009. The Cox proportional hazard model was used to calculate the multivariable hazard ratios with 95% CIs of all-cause mortality after adjusting for potential confounding factors. RESULTS: During the 18.5-year median follow-up period, 9253 cases were documented. Green tea consumption was inversely associated with all-cause mortality among stroke or MI survivors; the multivariable hazard ratios (95% CIs) for stroke survivors were 0.73 (0.42-1.27) for 1 to 6 cups/wk, 0.65 (0.36-1.15) for 1 to 2 cups/d, 0.56 (0.34-0.92) for 3 to 4 cups/d, 0.52 (0.31-0.86) for 5 to 6 cups/d, and 0.38 (0.20-0.71) for ≥7 cups/d, compared with nondrinkers. A similar inverse association was observed for MI survivors, but not evident for those without a history of stroke or MI. Coffee consumption was inversely associated with all-cause mortality in persons without a history of stroke or MI; the multivariable hazard ratios (95% CIs) were 0.86 (0.82-0.91) for 1 to 6 cups/wk, 0.86 (0.80-0.92) for 1 cup/d, and 0.82 (0.77-0.89) for ≥2 cups/d, compared with nondrinkers. The corresponding hazard ratios (95% CIs) for MI survivors were 0.69 (0.53-0.91), 0.78 (0.55-1.10), and 0.61 (0.41-0.90). No such association was observed for stroke survivors. CONCLUSIONS: Green tea consumption can be beneficial in improving the prognosis for stroke or MI survivors, whereas coffee consumption can also be so for persons without a history of stroke or MI as well as MI survivors.

Association of tea consumption and the risk of gastric cancer in Japanese adults: the Japan Collaborative Cohort Study.

OBJECTIVE: To examine the possible relationship between tea consumption and risk of gastric cancer (GC) among Japanese men and women included in a large Japanese population-based study titled the Japan Collaborative Cohort (JACC) Study. DESIGN: Prospective cohort study. SETTING: A population-based cohort included subjects who were recruited from 24 areas of JACC Study, in which data regarding the incidence of cancer were available. PARTICIPANTS: 63 848 participants (26 025 men and 37 823 women), aged 40-79, were included in the analyses and underwent follow-up (median 13.3 years) prospectively in research on cancer incidence. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome variable was the risk of GC according to the frequency intakes of total tea, green tea, black tea and oolong tea. The adjusted HRs for the risk of GC associated with tea consumption were calculated using the Cox proportional hazards model. RESULTS: 1494 cases of GC were detected (960 men and 534 women) during the follow-up period. The multivariable-adjusted HRs for the risk of GC in the highest versus lowest quintiles of total tea intake were 1.05 (0.83-1.33); p trend=0.50 in men, and 0.82 (0.60-1.12); p trend=0.45 in women. There was no association found between the consumption of green tea, black tea or oolong tea with the risk for GC in either gender. CONCLUSIONS: In this large community-based prospective cohort study, tea consumption was not associated with the risk of GC in either gender.

Coffee, green tea and liver cancer risk: an evaluation based on a systematic review of epidemiologic evidence among the Japanese population.

BACKGROUND: Coffee and green tea, two popular drinks in the Japanese, have recently drawn much attention as potential protective factors against the occurrence of liver cancer. METHODS: We systematically reviewed epidemiologic studies on coffee, green tea and liver cancer among Japanese populations. Original data were obtained by searching the MEDLINE (PubMed) and Ichushi databases, complemented with manual searches. The evaluation was performed in terms of the magnitude of association in each study and the strength of evidence ('convincing', 'probable', 'possible', or 'insufficient'), together with biological plausibility. RESULTS: We identified four cohort and four case-control studies on coffee and liver cancer and six cohort and one case-control studies on green tea and liver cancer. All cohort and case-control studies on coffee reported a weak to strong inverse association, with a summary relative risk (RR) for one cup increase being 0.72 (95% confidence interval [CI] 0.66-0.79). Conversely, all studies but two cohort studies on green tea reported no association, with a corresponding summary RR of 0.99 (95% CI 0.97-1.01, P = 0.37). CONCLUSION: Coffee drinking 'probably' decreases the risk of primary liver cancer among the Japanese population whereas the evidence on an association between green tea and liver cancer is 'insufficient' in this population.

Green tea consumption and mortality in Japanese men and women: a pooled analysis of eight population-based cohort studies in Japan.

The aim of our study was to assess the association between green tea consumption and all-cause and cause-specific mortality in a pooled analysis of eight Japanese population-based cohort studies. Pooled hazard ratios (HR) and 95% confidence intervals (CI), derived from random effects models, were used to evaluate the associations between green tea consumption, based on self-report at baseline, and risk of all-cause and cause-specific mortality. During a mean follow-up of 17.3 years, among 313,381 persons, 52,943 deaths occurred. Compared with individuals who consumed < 1 cup/day, those in the highest consumption category (≥ 5 cups/day) had a decreased risk of all-cause mortality [the multivariate-adjusted HR was 0.90 (95% CI 0.87-0.94) for men and 0.82 (0.74-0.90) for women]. A similar inverse association was observed for heart disease mortality [HR 0.82 (0.75-0.90) for men, and 0.75 (0.68-0.84) for women], and cerebrovascular disease mortality [HR 0.76 (0.68-0.85) for men, and 0.78 (0.68-0.89) for women]. Among women, green tea consumption was associated with decreased risk of total cancer mortality: 0.89 (0.83-0.96) for the 1-2 cups/day category and 0.91 (0.85-0.98) for the 3-4 cups/day category. Results for respiratory disease mortality were [HR 0.75 (0.61-0.94)] among 3-4 cup daily consumers and [HR 0.66 (0.55-0.79)] for ≥ 5 cups/day. Higher consumption of green tea is associated with lower risk for all-cause mortality in Japanese, especially for heart and cerebrovascular disease. Moderate consumption decreased the risk of total cancer and respiratory disease mortality in women.

Green tea consumption and risk of hematologic neoplasms: the Japan Collaborative Cohort Study for Evaluation of Cancer Risk (JACC Study).

PURPOSE: Experimental studies suggested that green tea may have an anticancer effect on hematologic neoplasms. However, few prospective studies have been conducted. METHODS: A total of 65,042 individuals aged 40-79 years participated in this study and completed a self-administered questionnaire about their lifestyle and medical history at baseline (1988-1990). Of these, 52,462 individuals living in 24 communities with information on incident hematologic neoplasms available in the cancer registry, who did not have a history of cancer and provided valid information on frequency of green tea consumption, were followed through 2009. Hazard ratios (HRs) and 95% confidence intervals (CIs) for the incidence of hematologic neoplasms according to green tea consumption were analyzed. RESULTS: The incidence of hematologic neoplasms during a median follow-up of 13.3 years was 323. Compared with the never-drinkers of green tea, the multivariate HRs and 95% CIs for total hematologic neoplasms in green tea drinkers of ≤ 2 cups/day, 3-4 cups/day, and ≥ 5 cups/day were 0.65 (0.42-1.00), 0.73 (0.47-1.13), and 0.63 (0.42-0.96), respectively. The association was more prominent for acute myeloid leukemias and follicular lymphomas. CONCLUSIONS: The present cohort study suggests a protective effect of green tea against hematologic neoplasms, especially acute myeloid leukemias.

Coffee consumption and mortality in Japanese men and women: A pooled analysis of eight population-based cohort studies in Japan (Japan Cohort Consortium).

Coffee consumption is increasing globally. We aimed to assess the effect of coffee consumption on the risk of all-cause and cause-specific mortality in a pooled analysis of eight population-based cohort studies in Japan (Japan Cohort Consortium). Data came from eight Japanese cohort studies (144,750 men and 168,631 women). During a mean follow-up time of 17 years, 52,943 deaths occurred. More specifically, 19,495 cancer deaths, 7321 deaths due to heart disease, 6387 cerebrovascular, 3490 respiratory disease and 3382 injuries and accidents. A random effects model was applied to obtain pooled hazard ratios (HRs) and 95% confidence intervals (95%CIs). In both sexes, coffee consumption up to 5 cups/day was overall protective in relation to all-cause mortality, with the association attenuating in the highest category of coffee consumption (≥5 cups/day). In men, a similar inverse association was observed for major causes of mortality except cancer. In women, coffee consumption decreased the risk for mortality due to heart disease in the 1-2 cups/day category, but increased the risk in the ≥5 cups/day category. Coffee consumption was not associated with cancer in both sexes. Results were similar among male current smokers and female never-smokers. Based on available data, this pooled analysis suggests that coffee consumption under five cups per day may be beneficial for reducing the risk of mortality due to major causes.

Circulating isoflavone and lignan concentrations and prostate cancer risk: a meta-analysis of individual participant data from seven prospective studies including 2,828 cases and 5,593 controls.

Phytoestrogens may influence prostate cancer development. This study aimed to examine the association between prediagnostic circulating concentrations of isoflavones (genistein, daidzein, equol) and lignans (enterolactone and enterodiol) and the risk of prostate cancer. Individual participant data were available from seven prospective studies (two studies from Japan with 241 cases and 503 controls and five studies from Europe with 2,828 cases and 5,593 controls). Because of the large difference in circulating isoflavone concentrations between Japan and Europe, analyses of the associations of isoflavone concentrations and prostate cancer risk were evaluated separately. Prostate cancer risk by study-specific fourths of circulating concentrations of each phytoestrogen was estimated using multivariable-adjusted conditional logistic regression. In men from Japan, those with high compared to low circulating equol concentrations had a lower risk of prostate cancer (multivariable-adjusted OR for upper quartile [Q4] vs. Q1 = 0.61, 95% confidence interval [CI] = 0.39-0.97), although there was no significant trend (OR per 75 percentile increase = 0.69, 95 CI = 0.46-1.05, ptrend = 0.085); Genistein and daidzein concentrations were not significantly associated with risk (ORs for Q4 vs. Q1 = 0.70, 0.45-1.10 and 0.71, 0.45-1.12, respectively). In men from Europe, circulating concentrations of genistein, daidzein and equol were not associated with risk. Circulating lignan concentrations were not associated with the risk of prostate cancer, overall or by disease aggressiveness or time to diagnosis. There was no strong evidence that prediagnostic circulating concentrations of isoflavones or lignans are associated with prostate cancer risk, although further research is warranted in populations where isoflavone intakes are high.

Fish Intake and Death From Pulmonary Embolisms Among Japanese Men and Women　- The Japan Collaborative Cohort (JACC) Study.

BACKGROUND: Numerous studies have reported the association of cardiovascular risk factors with pulmonary embolism (PE), but the association of dietary factors, especially fish intake, with the risk of PE has not been fully established.Methods and Results:Using a prospective design, we studied the risk of PE mortality in relation to fish intake in 90,791 community-dwelling men and women in Japan aged 40-79 years. The hazard ratios (HRs) and 95% confidence intervals (CIs) for PE death were estimated using the Cox proportional hazards model. Compared with participants in the lowest fresh fish intake group (<1 time/month), the HRs (95% CIs) for PE death for those in the other intake groups were 0.35 (0.08-1.59) for 1-2 times/month, 0.19 (0.05-0.69) for 1-2 times/week, 0.20 (0.06-0.74) for 3-4 times/week, and 0.18 (0.05-0.66) for fish intake every day. In addition to these findings, compared with the participants in the lowest 10% of ω3 polyunsaturated fatty acid intake, those in the other groups had a 60-76% lower risk of PE death. CONCLUSIONS: Fresh fish intake, even 1-2 times/week, is associated with a lower risk of death from PE among Japanese men and women.

Coffee drinking and colorectal cancer and its subsites: A pooled analysis of 8 cohort studies in Japan.

Coffee is a rich source of bioactive compounds that have potential anticarcinogenic effects. However, it remains unclear whether coffee drinking is associated with colorectal cancer. Also, despite different etiological factors involved in gut physiology, few studies have investigated this association by anatomical site of the lesion. To address these issues, this study examined the association between coffee drinking and colorectal cancer in a pooled analysis from 8 cohort studies conducted in Japan. Among 320,322 participants followed up for 4,503,274 person-years, 6,711 incident colorectal cancer cases were identified. Study-specific hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models and then pooled using the random effects model. Coffee drinking was not materially associated with colorectal cancer risk in men or women (pooled HR 0.92, 95% CI 0.82-1.03 in men and pooled HR 0.90, 95% CI 0.76-1.07 in women). Analysis by subsite showed a lower risk of colon cancer among female drinkers of ≥3 cups coffee/day (pooled HR 0.80, 95% CI 0.64-0.99). There was no such association in men. Coffee drinking was not associated with risk of rectal cancer in men or women. Results were virtually the same among never smokers except for an increased risk of rectal cancer associated with frequent coffee consumption. Coffee drinking may be associated with lower risk of colon cancer in Japanese women.

Coffee drinking and colorectal cancer risk: an evaluation based on a systematic review and meta-analysis among the Japanese population.

OBJECTIVE: It remains unclear whether coffee drinking is associated with colorectal cancer risk. We performed a systematic review and meta-analysis of epidemiologic studies on this issue among the Japanese population. METHODS: Original data were obtained from MEDLINE searches using PubMed or from searches of the 'Ichushi' database, complemented with manual searches. Meta-analysis was performed by using the random effects model to estimate the summary relative risk with 95% confidence interval according to the study design. The final judgment was made based on a consensus of the research group members with consideration for both epidemiological evidence and biological plausibility. RESULTS: We identified five cohort studies and nine case-control studies. Of these, one cohort study reported a strong inverse association (in women only), whereas three case-control studies reported a strong inverse association with colon or rectal cancer. In meta-analysis, high consumption of coffee was not appreciably associated with colorectal cancer risk among cohort studies, whereas it was associated with significantly lower risk of colorectal or colon cancer among case-control studies. The summary relative risk/odds ratio (95% confidence interval) for the highest versus lowest categories of coffee consumption was 0.95 (0.77-1.17) and 0.78 (0.65-0.95) for cohort and case-control studies, respectively. CONCLUSIONS: The evidence is insufficient to support that coffee drinking increases or decreases the risk of colorectal cancer among the Japanese population.

Multivitamin use and risk of stroke mortality: the Japan collaborative cohort study.

BACKGROUND AND PURPOSE: An effect of multivitamin supplement on stroke risk is uncertain. We aimed to examine the association between multivitamin use and risk of death from stroke and its subtypes. METHODS: A total of 72 180 Japanese men and women free from cardiovascular diseases and cancers at baseline in 1988 to 1990 were followed up until December 31, 2009. Lifestyles including multivitamin use were collected using self-administered questionnaires. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) of total stroke and its subtypes in relation to multivitamin use. RESULTS: During a median follow-up of 19.1 years, we identified 2087 deaths from stroke, including 1148 ischemic strokes and 877 hemorrhagic strokes. After adjustment for potential confounders, multivitamin use was associated with lower but borderline significant risk of death from total stroke (HR, 0.87; 95% confidence interval, 0.76-1.01), primarily ischemic stroke (HR, 0.80; 95% confidence interval, 0.63-1.01), but not hemorrhagic stroke (HR, 0.96; 95% confidence interval, 0.78-1.18). In a subgroup analysis, there was a significant association between multivitamin use and lower risk of mortality from total stroke among people with fruit and vegetable intake <3 times/d (HR, 0.80; 95% confidence interval, 0.65-0.98). That association seemed to be more evident among regular users than casual users. Similar results were found for ischemic stroke. CONCLUSIONS: Multivitamin use, particularly frequent use, was associated with reduced risk of total and ischemic stroke mortality among Japanese people with lower intake of fruits and vegetables.

Coffee consumption and risk of colorectal cancer: the Japan Collaborative Cohort Study.

BACKGROUND: Epidemiologic studies have reported coffee consumption to be associated with various health conditions. The purpose of this study was to examine the relationship of coffee consumption with colorectal cancer incidence in a large-scale prospective cohort study in Japan. METHODS: We used data from the Japan Collaborative Cohort Study for Evaluation of Cancer Risk (JACC Study). Here, we analyzed a total of 58 221 persons (23 607 men, 34 614 women) followed from 1988 to the end of 2009. During 738 669 person-years of follow-up for the analysis of colorectal cancer risk with coffee consumption at baseline, we identified 687 cases of colon cancer (355 males and 332 females) and 314 cases of rectal cancer (202 males and 112 females). We used the Cox proportional-hazard regression model to estimate hazard ratio (HR). RESULTS: Compared to those who consumed less than 1 cup of coffee per day, men who consumed 2-3 cups of coffee per day had an HR of 1.26 (95% confidence interval [CI] 0.93-1.70), and men who consumed more than 4 cups of coffee per day had an HR of 1.79 (95% CI 1.01-3.18). A statistically significant increase in the risk of colon cancer was associated with increasing coffee consumption among men (P for trend = 0.03). On the other hand, coffee consumption in women was not associated with incident risk of colon cancer. Coffee consumption was also not associated with rectal cancer incidence in men or women. CONCLUSIONS: This large-scale population-based cohort study showed that coffee consumption increases the risk of colon cancer among Japanese men.

Green tea consumption and gastric cancer risk: an evaluation based on a systematic review of epidemiologic evidence among the Japanese population.

OBJECTIVE: Numerous in vitro and animal studies have shown that green tea has a protective effect against cancer. However, results from epidemiologic studies are conflicting. We evaluated the association between green tea consumption and risk for gastric cancer risk among the Japanese population based on a systematic review of epidemiologic evidence. METHODS: Original data were obtained from MEDLINE searches using PubMed or from searches of the Ichushi database, complemented with manual searches. Evaluation of associations was based on the strength of evidence and the magnitude of association, together with biologic plausibility. RESULTS: Eight cohort studies and three case-control studies were identified. Overall, we found no preventive effect on gastric cancer for green tea intake in cohort studies. However, a small, consistent risk reduction limited to women was observed, which was confirmed by pooling data of six cohort studies (hazard ratio = 0.79, 95% confidence interval 0.65-0.96 with ≥5 cups/day of green tea intake). Case-control studies consistently showed a weak inverse association between green tea intake and gastric cancer risk. CONCLUSIONS: We conclude that green tea possibly decreases the risk of gastric cancer in women. However, epidemiologic evidence is still insufficient to demonstrate any association in men.

Effect of coffee consumption on all-cause and total cancer mortality: findings from the JACC study.

Coffee consumption is known to be related to various health conditions. Recently, its antioxidant effects have been suggested to be associated with all-cause or cancer mortality by various cohort studies. However, there has been only one small Asian cohort study that has assessed this association. Thus, we tried to assess the association of coffee with all-cause and total cancer mortality by conducting a large-scale cohort study in Japan. A total of 97,753 Japanese men and women aged 40-79 years were followed for 16 years. Hazard ratios and 95% confidence intervals of all-cause and total cancer mortality in relation to coffee consumption were calculated from proportional-hazards regression models. A total of 19,532 deaths occurred during the follow-up period; 34.8% of these deaths were caused by cancer. The all-cause mortality risk decreased with increasing coffee consumption in both men and women, with a risk elevation at the highest coffee consumption level (≥4 cups/day) compared with the 2nd highest consumption level in women, although the number of subjects evaluated at this level was small. No association was found between coffee consumption and total cancer mortality among men, whereas a weak inverse association was found among women. The present cohort study among the Japanese population suggested that there are beneficial effects of coffee on all-cause mortality among both men and women. Furthermore, the results showed that coffee consumption might not be associated with an increased risk of total cancer mortality.

Coffee, green tea, black tea and oolong tea consumption and risk of mortality from cardiovascular disease in Japanese men and women.

BACKGROUND: The effects of coffee and green, black and oolong teas and caffeine intake on cardiovascular disease (CVD) mortality have not been well defined in Asian countries. METHODS: To examine the relationship between the consumption of these beverages and risk of mortality from CVD, 76,979 individuals aged 40-79 years free of stroke, coronary heart disease (CHD) and cancer at entry were prospectively followed. The daily consumption of beverages was assessed by questionnaires. RESULTS: 1362 deaths were documented from strokes and 650 deaths from CHD after 1,010,787 person-years of follow-up. Compared with non-drinkers of coffee, the multivariable HR and 95% CI for those drinking 1-6 cups/week, 1-2 cups/day and ≥ 3 cups/day were 0.78 (0.50 to 1.20), 0.67 (0.47 to 0.96) and 0.45 (0.17 to 0.87) for strokes among men (p = 0.009 for trend). Compared with non-drinkers of green tea, the multivariable HR for those drinking 1-6 cups/week, 1-2 cups/day, 3-5 cups/day and ≥ 6 cups/day were 0.34 (0.06-1.75), 0.28 (0.07-1.11), 0.39 (0.18-0.85) and 0.42 (0.17-0.88) for CHD among women (p = 0.038 for trend). As for oolong tea, the multivariable HR of those drinking 1-6 cups/week and ≥ 1 cups/day were 1.00 (0.65-1.55) and 0.39 (0.17-0.88) for total CVD among men (p = 0.049 for trend). Risk reduction for total CVD across categories of caffeine intake was most prominently observed in the second highest quintile, with a 38% lower risk among men and 22% among women. CONCLUSIONS: Consumption of coffee, green tea and oolong tea and total caffeine intake was associated with a reduced risk of mortality from CVD.