Reproducibility and dietary correlates of plasma polyphenols in the JPHC-NEXT Protocol Area study.

BACKGROUND: In recent years, an increasing number of epidemiological studies have suggested a role of polyphenols in the prevention of chronic diseases. Prospective cohort studies have typically measured polyphenol concentrations in a single blood sample and the reproducibility of plasma polyphenol measurements is largely unknown. OBJECTIVE: We evaluated the reproducibility of 35 plasma polyphenols collected at an interval of 1-year. We also examined correlations of these polyphenols with food group intakes calculated from weighed food records (WFR) and food frequency questionnaire (FFQ). METHODS: The study included 227 middle-aged participants from the JPHC-NEXT Protocol Area in Japan. We measured 35 polyphenols in plasma collected at two points 1-year apart. Food group intakes were calculated from 12-day WFR and FFQ. For the reproducibility analysis, the intraclass correlation coefficient (ICC) of 35 polyphenol concentrations were examined between the two points. Pearson's partial correlations was used to assess the correlation between polyphenols and food groups. RESULTS: Moderate- to high ICCs were observed for tea-originated polyphenols such as gallic acid, quercetin, epigallocatechin, and kaempferol - and coffee-derived polyphenols, such as caffeic acid, and ferulic acid. For the dietary analyses, moderate correlations were observed for non-alcoholic beverages intake and epigallocatechin, epicatechin, catechin, and gallic acid. For green tea, higher correlations were observed with these polyphenols. CONCLUSION: Plasma concentrations of tea and coffee-related polyphenols, except for catechin, had good reproducibility over a 1-year period. The correlations between intake of non-alcoholic beverages, particularly green tea, and tea polyphenols, indicated moderate- to high correlations.

Green tea and coffee consumption and risk of kidney cancer in Japanese adults.

The study aimed to evaluate the association between green tea and coffee consumption and the risk of kidney cancer using data from a large prospective cohort study in Japan (the Japan Public Health Center-based Prospective Study: JPHC Study). A total of 102,463 participants aged 40-69 were followed during 1,916,421 person-years (mean follow-up period, 19 years). A total of 286 cases of kidney cancer (199 in men, 87 in women) were identified. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (95% CIs) while adjusting for potential confounders. No statistically significant association between green tea intake and kidney cancer risk was found in the total population. Among women who consumed more than five cups of green tea per day, a statistically significant decreased risk was shown with a HR of 0.45 (95% CI: 0.23-0.89), compared to women who rarely consumed green tea. For coffee consumption, the association of kidney cancer risk was not statistically significant. This large prospective cohort study indicated green tea intake may be inversely associated with kidney cancer risk in Japanese adults, particularly in Japanese women.

Prediagnostic plasma polyphenol concentrations and colon cancer risk: The JPHC nested case-control study.

BACKGROUND & AIMS: Epidemiological studies that assessed the associations between dietary polyphenol intakes and colon cancer risk have reported largely null results, possibly due to measurement error associated with dietary assessment. We adopted an objective approach by measuring prediagnostic plasma concentrations of 35 polyphenols and assessing associations with colon cancer risk. METHODS: We conducted a nested-case control study within the Japan Public Health Center-based prospective study (JPHC Study) utilizing plasma samples collected at the time of a five-year follow-up survey between 1995 and 1999. We identified colon cancer cases who developed cancer during the follow-up from the time of blood collection. Controls were matched by age, sex, area code, population size of the area, season of blood collection, year of blood collection, and duration of fasting time before the blood collection. Prediagnostic concentrations of 35 polyphenols from 375 incident colon cancer cases (followed until 2012) and 710 matched controls were measured by tandem mass spectrometry coupled with ultra-high-pressure liquid chromatography. We used multivariable conditional logistic regression models adjusted for established colon cancer risk factors to estimate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: In sexes combined log2-transformed multivariable models, circulating levels of 3,4-dihydroxyphenylpropionic acid (P = 0.02), ferulic acid (P = 0.02), and caffeic acid (P = 0.03) were inversely, and 3-hydroxybenzoic acid (P = 0.03) was positively, associated with colon cancer risk. For men only, circulating levels of 3,4-dihydroxyphenylpropionic acid was inversely, and 3,5-dihydroxyphenylpropionic acid, gallic acid, (+)-epigallocatechin, 3-hydroxybenzoic acid, and epicatechin were positively, associated with colon cancer risk. In women, plasma caffeic acid and ferulic acid concentration were inversely associated with colon cancer risk. However, all these associations were nonsignificant after adjustment for multiple comparisons. The remaining polyphenols were not associated with colon cancer risk. CONCLUSION: Coffee-derived 3,4-dihydroxyphenylpropionic acid, ferulic acid, and caffeic acid concentrations were inversely associated with colon cancer risk although the association were nonsignificant after adjustment for multiple comparisons. These results support a possible role of coffee polyphenols in preventing colorectal cancer.

Association between Meat, Fish, and Fatty Acid Intake and Non-Hodgkin Lymphoma Incidence: The Japan Public Health Center-Based Prospective Study.

BACKGROUND: Meat, fish, and fatty acid intakes have been reported to be associated with non-Hodgkin lymphoma (NHL), although results have been inconclusive. We hypothesized that red meat and SFA intakes increase NHL risk, and fish and PUFA intakes decrease NHL risk. OBJECTIVES: We investigated the association between NHL incidence and meat, fish, and various fatty acid type intakes using the Japan Public Health Center-based Prospective Study. METHODS: The current cohort study included 93,366 participants aged 45-74 y who were eligible for analysis; they were followed up until December 2012. Participants answered an FFQ between 1995 and 1999. We analyzed the effects of meat, fish, total fatty acid, SFA, and PUFA intakes on NHL incidence using the Cox proportional hazard model. RESULTS: The median age was 57 y (IQR: 51-63 y), and 46.5% of the participants were men. Participants were followed up for 1,345,001 person-years, and 230 patients with NHL were identified. Total fatty acid and SFA intakes were associated with an increased incidence of NHL, with an adjusted HR of 1.56 (95% CI: 1.04, 2.34 highest compared with lowest quartile; P-trend = 0.062), and 1.63 (95% CI: 1.11, 2.41; P-trend = 0.074), respectively. In subtype analysis, total fatty acid and SFA intakes were also associated with increased incidence of follicular lymphoma but were not significantly associated with diffuse large B-cell lymphoma. Conversely, total meat, processed meat, unprocessed meat, red meat, poultry, fish, MUFA, PUFA, n-3 (ω-3) PUFA, and n-6 (ω-6) PUFA intakes were not significantly associated with the incidence of NHL or its subtypes. CONCLUSIONS: Total fatty acid and SFA intakes were associated with increased incidence of NHL in the Japanese adult population. Further large-scale studies are warranted to test whether fatty acid intakes affect the development of NHL.

Coffee and tea consumption and mortality from all causes, cardiovascular disease and cancer: a pooled analysis of prospective studies from the Asia Cohort Consortium.

BACKGROUND: Accumulating evidence suggests that consuming coffee may lower the risk of death, but evidence regarding tea consumption in Asians is limited. We examined the association between coffee and tea consumption and mortality in Asian populations. METHODS: We used data from 12 prospective cohort studies including 248 050 men and 280 454 women from the Asia Cohort Consortium conducted in China, Japan, Korea and Singapore. We estimated the study-specific association of coffee, green tea and black tea consumption with mortality using Cox proportional-hazards regression models and the pooled study-specific hazard ratios (HRs) using a random-effects model. RESULTS: In total, 94 744 deaths were identified during the follow-up, which ranged from an average of 6.5 to 22.7 years. Compared with coffee non-drinkers, men and women who drank at least five cups of coffee per day had a 24% [95% confidence interval (CI) 17%, 29%] and a 28% (95% CI 19%, 37%) lower risk of all-cause mortality, respectively. Similarly, we found inverse associations for coffee consumption with cardiovascular disease (CVD)-specific and cancer-specific mortality among both men and women. Green tea consumption was associated with lower risk of mortality from all causes, CVD and other causes but not from cancer. The association of drinking green tea with CVD-specific mortality was particularly strong, with HRs (95% CIs) of 0.79 (0.68, 0.91) for men and 0.78 (0.68, 0.90) for women who drank at least five cups per day of green tea compared with non-drinkers. The association between black tea consumption and mortality was weak, with no clear trends noted across the categories of consumption. CONCLUSIONS: In Asian populations, coffee consumption is associated with a lower risk of death overall and with lower risks of death from CVD and cancer. Green tea consumption is associated with lower risks of death from all causes and CVD.

Association between Coffee Consumption and Risk of Prostate Cancer in Japanese Men: A Population-Based Cohort Study in Japan.

BACKGROUND: Although numerous epidemiological studies have examined whether coffee consumption is associated with prostate cancer risk, the results remain controversial. Moreover, there are few studies in Asian populations. Therefore, we investigated the association between coffee consumption and the risk of prostate cancer in a large-scale prospective population-based cohort study in Japan. METHODS: Study subjects were 48,222 men (40-69 years) who completed a questionnaire that included questions about their coffee consumption in 1990 for Cohort I and 1993 for Cohort II and were followed up until December 31, 2015. Newly diagnosed cases were classified into localized and advanced using information on local staging, the Gleason score, and degree of differentiation. Hazard ratios (HR) and 95% confidential intervals (95% CI) were estimated using Cox regression analysis. RESULTS: A total of 1,617 participants were newly diagnosed with prostate cancer during a mean follow-up period of 18.8 years. Of these, 1,099 and 461 patients had localized and advanced cancer, respectively. There was no association between coffee intake and prostate cancer risk. Comparison between the highest and lowest category of coffee consumption produced HRs of 1.08 (95% CI, 0.90-1.30), 1.08 (95% CI, 0.84-1.38), and 1.00 (95% CI, 0.67-1.47) for risk of total, localized, and advanced cancer, respectively. The same results were obtained even when we limited the analysis to patients with subjective symptoms. CONCLUSIONS: Our findings suggest that coffee consumption has no impact on prostate cancer risk in Japanese men. IMPACT: Coffee has no protective effects against prostate cancer among Japanese men.

Sugary drink consumption and risk of kidney and bladder cancer in Japanese adults.

Globally, sugary drinks are widely consumed, however, few epidemiologic studies have investigated the association between sugary drink consumption and risk of kidney and bladder cancer. We examined the association of sugary drinks with risk of kidney and bladder cancer in 73,024 participants from the Japan Public Health Center-based Prospective Study who reported no history of cancer. Sugary drink consumption was assessed using a validated food frequency questionnaire at study baseline (1995-1999). Individuals were followed to December 31, 2013. Multivariable Cox proportional hazards regression models were used to calculate hazard ratios (HR) and 95% confidence intervals (CIs). During 1,069,815 person years of follow-up, 169 kidney cancer and 297 bladder cancer cases were documented. After adjusting for potential confounders, no greater risk of kidney and bladder cancer was observed. However, sugary drink consumption was positively associated with the risk of kidney cancer (HR for 100 ml/day increase in consumption was 1.11 [95% CI 1.01-1.22]) and bladder cancer (HR for 100 ml/d increase in consumption was 1.11 [95% CI 1.01-1.22]) among women after exclusion of cases diagnosed in the first three years of follow-up. In this large prospective cohort, consumption of sugary drinks was significantly associated with a small increase in hazard ratio for kidney and bladder cancer among women after exclusion of cases diagnosed within the first three years.

Dietary glycemic index, glycemic load, and endometrial cancer risk: The Japan Public Health Center-based Prospective Study.

Evidence supporting the association of glycemic index (GI) and glycemic load (GL) with the risk of endometrial cancer is controversial and reports from Asia were limited. Therefore, we aimed to investigate the association in Japanese women. We evaluated 52 460 women in the Japan Public Health Center-based Prospective Study aged 45-74 years who responded to the 5-year follow-up survey. GI and GL were calculated from a validated food frequency questionnaire, and the participants were divided into three groups by GI and GL. The hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated with the Cox proportional hazard model adjusted for potential confounding factors. As a result, within 15.5 years of follow-up, 166 new cases of endometrial cancer were identified. Compared with the lowest GI and GL tertile groups, the HR of the risk of endometrial cancer in the highest GI tertile group was 0.80 (95% CI, 0.53-1.20; Ptrend  = .33), and that of the highest GL tertile group was 0.79 (95% CI, 0.52-1.19; Ptrend  = .82). The results were unchanged after stratification by body mass index, coffee consumption, and history of diabetes. In conclusion, we did not find any significant association between GI and GL with the risk of endometrial cancer. Further research is required to clarify the association.

Green tea and cancer and cardiometabolic diseases: a review of the current epidemiological evidence.

Green tea is commonly consumed in China, Japan, and Korea and certain parts of North Africa and is gaining popularity in other parts of the world. The aim of this review was to objectively evaluate the existing evidence related to green tea consumption and various health outcomes, especially cancer, cardiovascular disease and diabetes. This review captured evidence from meta-analyses as well as expert reports and recent individual studies. For certain individual cancer sites: endometrial, lung, oral and ovarian cancer, and non-Hodgkins lymphoma the majority of meta-analyses observed an inverse association with green tea. Mixed findings were observed for breast, esophageal, gastric, liver and a mostly null association for colorectal, pancreatic, and prostate cancer. No studies reported adverse effects from green tea related to cancer although consuming hot tea has been found to possibly increase the risk of esophageal cancer and concerns of hepatotoxity were raised as a result of high doses of green tea. The literature overall supports an inverse association between green tea and cardiovascular disease-related health outcomes. The evidence for diabetes-related health outcomes is less convincing, while the included meta-analyses generally suggested an inverse association between green tea and BMI-related and blood pressure outcomes. Fewer studies investigated the association between green tea and other health outcomes such as cognitive outcomes, dental health, injuries and respiratory disease. This review concludes that green tea consumption overall may be considered beneficial for human health.

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.

Coffee Drinking and Reduced Risk of Liver Cancer: Update on Epidemiological Findings and Potential Mechanisms.

PURPOSE OF REVIEW: We reviewed the available literature on observational studies, meta-analyses, expert reports, and umbrella reviews. Here, we summarize the latest findings on the association between coffee intake and liver cancer risk. RECENT FINDINGS: Most observational studies and meta-analyses show a protective effect of coffee intake on liver cancer risk, with dose-responsiveness and across different populations, and regardless of hepatitis virus infection status. Risk reduction by coffee consumption has also been observed for chronic liver diseases. Potential mechanisms include the effect of a number of bioactive compounds such as caffeine, chlorogenic acids, phenolic compounds and diterpenes; antioxidant properties; induction of defense mechanisms; and anti-inflammatory properties. Other potential mechanisms include improvement in insulin sensitivity and prevention of metabolic syndrome and diabetes. Accumulated evidence, with consistency across study designs and populations, suggests that coffee intake probably reduces the risk of liver cancer. Future research should aim to elucidate the mechanism of this preventive effect with establishing the causality of an association.

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.

Addition of high load of lysophosphatidic acid to standard and high-fat chows causes no significant changes of its circulating and peripheral tissue levels but affects body weight and visceral fat mass of mice.

Oral administration of lysophosphatidic acid (LPA), a critical intercellular lipid mediator, exerts wound healing and antiulcer effects on gastrointestinal system. To evaluate effects of food-derived LPA on body homeostasis, we measured LPA levels by liquid chromatography-tandem mass spectrometry in chows, feces, plasma, liver, and visceral fat of mice fed a normal or high-fat chow supplemented with or without LPA-rich soybean phospholipids for 30 days. Reductions in daily body weight gains and visceral fat mass were mainly related to lower chow intake by mice fed the LPA-rich high-fat chow, whereas reduced body weight gains and fat mass were mainly related to decreased intestinal triacylglycerol absorption in mice fed LPA-rich chow. Our results showed no significant increase in plasma, liver, or adipose LPA levels, even if a quite high LPA concentration (2.0%) in chows was ingested daily, suggesting limited effects of food-derived LPA on the lumen side of the digestive tract. © 2018 BioFactors, 44(6):548-557, 2018.

Plasma tea catechins and risk of cardiovascular disease in middle-aged Japanese subjects: The JPHC study.

BACKGROUND AND AIMS: Although a potential benefit of drinking green tea has been suggested to reduce the development of cardiovascular disease, no study has investigated the relationship between plasma tea catechin and risk of cardiovascular disease. METHODS: A prospective, nested case-control study was conducted to examine the association between plasma tea catechin and risk of stroke and coronary heart disease (CHD) in a cohort of 29,876 men and women aged 40-69 years without history of heart disease, stroke or cancer. Participants completed a survey and donated blood samples between 1990 and 1994, and were followed-up through 2008. A total of 1132 stroke cases and 209 CHD cases, matched 1:1 to controls (n = 1132) for stroke and 1:2 to controls (n = 418) for CHD, were included in the analysis. RESULTS: We found no significant association between plasma tea catechin and the incidence of stroke or CHD in either men or women. However, we found that high plasma levels of epigallocatechin gallate (EGCG) were associated with reduced risk of stroke in non-smoking men; the adjusted odds ratio (95% CI) for the highest vs. non-detectable levels was 0.53 (0.29-0.98). The respective OR in male smokers was 1.23 (0.75-2.16). A significant interaction by smoking status was found for the highest vs. non-detected plasma EGCG in relation to stroke (p-for-interaction: p = 0.09). CONCLUSIONS: Plasma tea catechin was not associated with reduced risks of either stroke or CHD, while a protective effect of certain tea catechin on stroke risk is suggested for male non-smokers.

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.

Dietary consumption of antioxidant vitamins and subsequent lung cancer risk: The Japan Public Health Center-based prospective study.

While many epidemiological studies have studied the association between lung cancer risk and fruits and vegetable consumption (the major sources of antioxidant vitamins), only a few have investigated the direct association with antioxidants in consideration of cancer subtypes and smoking status. Here, we examined the association between consumption of antioxidant vitamins and lung cancer risk in one of the largest prospective cohort studies in Japan. We investigated the association of dietary antioxidant vitamins intake, namely retinol, vitamin C, vitamin E, α-carotene, and ß-carotene and subsequent incidence of lung cancer among 38,207 men and 41,498 women in the Japan Public Health Center-based prospective study. Cox proportional hazard regression was performed with adjustment for potential confounders and by strata of cancer subtypes and smoking status. Antioxidant and other dietary intakes were assessed using a food frequency questionnaire (FFQ). During 1,233,096 person-years of follow-up between 1995 and 2013, a total of 1,690 lung cancer cases were newly diagnosed. In a multivariate regression model, while higher retinol intake was positively associated with overall lung cancer risk in men (HR 1.26; 95% CI 1.05-1.51; ptrend = 0.003), the estimates were more evident with small cell carcinoma (HR 1.92; 95% CI 1.13-3.24; ptrend < 0.001). Null associations were observed for other antioxidant vitamins. Our prospective study suggests that higher consumption of retinol may be associated with an increased risk of lung cancer in men, especially with small cell carcinoma, although confirmation is required.

Coffee Consumption and Lung Cancer Risk: The Japan Public Health Center-Based Prospective Study.

BACKGROUND: Many epidemiological studies have indicated a positive association between coffee intake and lung cancer risk, but such findings were suggested to be confounded by smoking. Furthermore, only a few of these studies have been conducted in Asia. Here, we investigated the association between coffee intake and lung cancer risk in one of the largest prospective cohort studies in Japan. METHODS: We investigated the association of coffee drinking and subsequent incidence of lung cancer among 41,727 men and 45,352 women in the Japan Public Health Center-based Prospective Study using Cox proportional hazards regression, with adjustment for potential confounders and by strata of smoking status. Coffee and other dietary intakes were assessed once at baseline with a food frequency questionnaire (FFQ). RESULTS: During 1,481,887 person-years of follow-up between 1990 and 2011, a total of 1,668 lung cancer cases were identified. In a multivariate regression model, coffee consumption was not associated with risk of lung cancer (HR 1.16; 95% CI, 0.82-1.63; Ptrend = 0.285 for men and HR 1.49; 95% CI, 0.79-2.83; Ptrend = 0.942 for women). However, there was a significant increase in the risk for small cell carcinoma (HR 3.52; 95% CI, 1.49-8.28; Ptrend < 0.001). CONCLUSION: Our prospective study suggests that habitual consumption of coffee is not associated with an increased risk of lung cancer incidence, despite observing a significant increase in the risk for small cell carcinoma.

Coffee and green tea consumption and subsequent risk of acute myeloid leukemia and myelodysplastic syndromes in Japan.

Although coffee and green tea are suggested to reduce the risk of some types of cancers, only a few epidemiological studies have investigated their effect on the risk of acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS). Here, we investigated the association of coffee and green tea consumption and the risk of AML and MDS in a large-scale population-based cohort study in Japan. A total of 95,807 Japanese subjects (45,937 men and 49,870 women; age 40-69 years at baseline) were followed to the end of 2012, for an average of 18 years. Hazard ratios (HRs) and 95% confidence intervals (95% CIs) for the association between coffee and green tea consumption at baseline and the risk of AML and MDS were assessed using a Cox proportional hazards model with adjustment for potential confounders. During 1,751.956 person-years, we identified 85 AML cases and 70 MDS cases. Our findings showed no significant association between coffee consumption and the risk of AML, or between green tea consumption and the risk of AML or MDS. In contrast, we observed a decreasing dose-response relationship between coffee consumption and the risk of MDS among men (almost none: reference, 1-4 times/week: HR = 0.83, 95% CI: 0.43-1.62; ≥1cups/day: HR = 0.47, 0.22-0.99, p for trend = 0.049). Stratified analysis by smoking status suggested that the observed relative risk for AML and MDS of coffee drinkers relative to non-coffee drinkers might be due to residual confounding by smoking. These findings deserve further investigation in future studies.

Coffee and Green Tea Consumption and Subsequent Risk of Malignant Lymphoma and Multiple Myeloma in Japan: The Japan Public Health Center-based Prospective Study.

Background: The aim of this study was to investigate the association of coffee and green tea consumption and the risk of malignant lymphoma and multiple myeloma in a large-scale population-based cohort study in Japan.Methods: In this analysis, a total of 95,807 Japanese subjects (45,937 men and 49,870 women; ages 40-69 years at baseline) of the Japan Public Health Center-based Prospective Study who completed a questionnaire about their coffee and green tea consumption were followed up until December 31, 2012, for an average of 18 years. HRs and 95% confidence intervals were estimated using a Cox regression model adjusted for potential confounders as a measure of association between the risk of malignant lymphoma and multiple myeloma associated with coffee and green tea consumption at baseline.Results: During the follow-up period, a total of 411 malignant lymphoma cases and 138 multiple myeloma cases were identified. Overall, our findings showed no significant association between coffee or green tea consumption and the risk of malignant lymphoma or multiple myeloma for both sexes.Conclusions: In this study, we observed no significant association between coffee or green tea consumption and the risk of malignant lymphoma or multiple myeloma.Impact: Our results do not support an association between coffee or green tea consumption and the risk of malignant lymphoma or multiple myeloma. Cancer Epidemiol Biomarkers Prev; 26(8); 1352-6. ©2017 AACR.