Search

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 ., (©2017 American Association for Cancer Research.)

Few prospective studies have investigated the etiology of brain tumor, especially among Asian populations. Both coffee and green tea are popular beverages, but their relation with brain tumor risk, particularly with glioma, has been inconsistent in epidemiological studies. In this study, we evaluated the association between coffee and greed tea intake and brain tumor risk in a Japanese population. We evaluated a cohort of 106,324 subjects (50,438 men and 55,886 women) in the Japan Public Health Center-Based Prospective Study (JPHC Study). Subjects were followed from 1990 for Cohort I and 1993 for Cohort II until December 31, 2012. One hundred and fifty-seven (70 men and 87 women) newly diagnosed cases of brain tumor were identified during the study period. Hazard ratio (HR) and 95% confidence intervals (95%CIs) for the association between coffee or green tea consumption and brain tumor risk were assessed using a Cox proportional hazards regression model. We found a significant inverse association between coffee consumption and brain tumor risk in both total subjects (≥3 cups/day; HR = 0.47, 95%CI = 0.22-0.98) and in women (≥3 cups/day; HR = 0.24, 95%CI = 0.06-0.99), although the number of cases in the highest category was small. Furthermore, glioma risk tended to decrease with higher coffee consumption (≥3 cups/day; HR = 0.54, 95%CI = 0.16-1.80). No association was seen between green tea and brain tumor risk. In conclusion, our study suggested that coffee consumption might reduce the risk of brain tumor, including that of glioma, in the Japanese population., (© 2016 UICC.)

Green tea and coffee consumption may decrease the risk of some types of cancers. However, their effects on biliary tract cancer (BTC) have been poorly understood. In this population-based prospective cohort study in Japan, we investigated the association of green tea (total green tea, Sencha, and Bancha/Genmaicha) and coffee consumption with the risk for BTC and its subtypes, gallbladder cancer, and extrahepatic bile duct cancer. The hazard ratios and 95% confidence intervals were calculated using the Cox proportional hazard model. A total of 89 555 people aged 45-74 years were enrolled between 1995 and 1999 and followed up for 1 138 623 person-years until 2010, during which 284 cases of BTC were identified. Consumption of >720 mL/day green tea was significantly associated with decreased risk compared with consumption of ≤120 mL/day (hazard ratio = 0.67 [95% confidence interval, 0.46-0.97]), and a non-significant trend of decreased risk associated with increased consumption was observed (P-trend = 0.095). In the analysis according to the location of the primary tumor, consuming >120 mL green tea tended to be associated with decreased risk of gallbladder cancer and extrahepatic bile duct cancer. When Sencha and Bancha/Genmaicha were analyzed separately, we observed a non-significant trend of decreased risk of BTC associated with Sencha but no association with Bancha/Genmaicha. For coffee, there was no clear association with biliary tract, gallbladder, or extrahepatic bile duct cancer. Our findings suggest that high green tea consumption may lower the risk of BTC, and the effect may be attributable to Sencha consumption., (© 2015 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)

Purpose: We examined the association between green tea consumption and mortality due to all causes, cancer, heart disease, cerebrovascular disease, respiratory disease, injuries, and other causes of death in a large-scale population-based cohort study in Japan., Methods: We studied 90,914 Japanese (aged between 40 and 69 years) recruited between 1990 and 1994. After 18.7 years of follow-up, 12,874 deaths were reported. The association between green tea consumption and risk of all causes and major causes of mortality was assessed using the Cox proportional hazards regression model with adjustment for potential confounders., Results: Hazard ratios for all-cause mortality among men who consumed green tea compared with those who drank less than 1 cup/day were 0.96 (0.89-1.03) for 1-2 cups/day, 0.88 (0.82-0.95) for 3-4 cups/day, and 0.87 (0.81-0.94) for more than 5 cups/day (P for trend <.001). Corresponding hazard ratios for women were 0.90 (0.81-1.00), 0.87 (0.79-0.96), and 0.83 (0.75-0.91; P for trend <.001). Green tea was inversely associated with mortality from heart disease in both men and women and mortality from cerebrovascular disease and respiratory disease in men. No association was found between green tea and total cancer mortality., Conclusions: This prospective study suggests that the consumption of green tea may reduce the risk of all-cause mortality and the three leading causes of death in Japan., (Copyright © 2015 Elsevier Inc. All rights reserved.)

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.

Background: The anticarcinogenic potential of green tea and coffee might be expected to reduce the risk of thyroid cancer, but epidemiological evidence is sparse. We examined green tea and coffee consumption in association with thyroid cancer risk in a general Japanese population., Methods: We analyzed data from a prospective cohort of 100,507 persons (48,802 men; 51,705 women) aged 40-69. Green tea and coffee consumption were assessed via a self-administered questionnaire. During a mean 14.2-year follow-up, we documented 159 thyroid cancer cases (26 in men; 133 in women), and Cox regression were used to calculated hazard ratios (HRs)., Results: Green tea consumption was not found to be associated with thyroid cancer risk in general. However, when women were stratified by menopausal status, the multivariable HR for ≥ 5 cups/day versus <1 cup/day was 1.66 (95% confidence interval (CI) = 0.85-3.23, trend p = 0.04) in premenopausal women, and was 0.47 (95% CI = 0.23-0.96, trend p = 0.06) in postmenopausal women. We found no association between coffee consumption and thyroid cancer risk in either sex., Conclusions: High green tea consumption may be positively associated with premenopausal thyroid cancer risk, but inversely associated with postmenopausal thyroid cancer risk.

Although many in vitro and animal studies have suggested a protective effect of green tea against breast cancer, findings from epidemiological studies have been inconsistent. No study has used prediagnostic biomarkers of tea polyphenols, which might play a protective role. A total of 24,226 women aged 40 to 69 years in the Japan Public Health Center-based Prospective Study who responded to the baseline questionnaire and provided blood in 1990-1995 were followed to December 2002. During a mean 10.6 years of follow-up, 144 newly diagnosed breast cancers were identified. Two matched controls for each case were selected from the cohort. Plasma levels of (-)-epigallocatechin (EGC), (-)-epicatechin (EC), (-)-epigallocatechin-3-gallate (EGCG), and (-)-epicatechin-3-gallate (ECG) were measured, and the odds ratio (OR) of breast cancer according to plasma level was estimated using a conditional logistic regression model. We found no statistically significant association between plasma tea polyphenol levels and breast cancer risk. Adjusted ORs for the highest versus lowest group were 0.90 (95% CI 0.42-1.96; P for trend = 0.98) for EGC, 0.95 (95% CI 0.43-2.08; P for trend = 0.86) for EC, 1.21 (95% CI 0.52-2.80; P for trend = 0.53) for EGCG, and 1.75 (95% CI 0.81-3.78; P for trend = 0.15) for ECG. Stratified analyses according to baseline menopausal status showed no remarkable difference between two strata. This nested case-control study found no overall association between plasma tea polyphenols and the risk of breast cancer in Japan.

Introduction: Although many in-vitro and animal studies have demonstrated a protective effect of green tea against breast cancer, findings from epidemiological studies have been inconsistent, and whether high green tea intake reduces the risk of breast cancer remains unclear., Methods: In this Japan Public Health Center-based Prospective Study, 581 cases of breast cancer were newly diagnosed in 53,793 women during 13.6 years' follow-up from the baseline survey in 1990-94. After the 5-year follow-up survey in 1995-98, 350 cases were newly diagnosed in 43,639 women during 9.5 years' follow-up. The baseline questionnaire assessed the frequency of total green tea drinking while the 5-year follow-up questionnaire assessed that of two types of green tea, Sencha and Bancha/Genmaicha, separately., Results: Compared with women who drank less than 1 cup of green tea per week, the adjusted hazard ratio [HR] for women who drank 5 or more cups per day was 1.12 (95% confidence interval [CI] 0.81-1.56; P for trend = 0.60) in the baseline data. Similarly, compared with women who drank less than 1 cup of Sencha or Bancha/Genmaicha per week, adjusted HRs for women who drank 10 or more cups per day were 1.02 (95% CI 0.55-1.89; P for trend = 0.48) for Sencha and 0.86 (0.34-2.17; P for trend = 0.66) for Bancha/Genmaicha. No inverse association was found regardless of hormone receptor-defined subtype or menopausal status., Conclusions: In this population-based prospective cohort study in Japan we found no association between green tea drinking and risk of breast cancer.

Background: Previous experimental studies have suggested many possible anti-cancer mechanisms for green tea, but epidemiological evidence for the effect of green tea consumption on gastric cancer risk is conflicting., Objective: To examine the association between green tea consumption and gastric cancer., Methods: We analysed original data from six cohort studies that measured green tea consumption using validated questionnaires at baseline. Hazard ratios (HRs) in the individual studies were calculated, with adjustment for a common set of variables, and combined using a random-effects model., Results: During 2 285 968 person-years of follow-up for a total of 219 080 subjects, 3577 cases of gastric cancer were identified. Compared with those drinking <1 cup/day, no significant risk reduction for gastric cancer was observed with increased green tea consumption in men, even in stratified analyses by smoking status and subsite. In women, however, a significantly decreased risk was observed for those with consumption of > or =5 cups/day (multivariate-adjusted pooled HR = 0.79, 95% confidence interval (CI) = 0.65 to 0.96). This decrease was also significant for the distal subsite (HR = 0.70, 95% CI = 0.50 to 0.96). In contrast, a lack of association for proximal gastric cancer was consistently seen in both men and women., Conclusions: Green tea may decrease the risk of distal gastric cancer in women.

Coffee and caffeine consumption are thought to increase the risk of bladder cancer. However, few studies have stratified this risk by smoking status, which is a potential confounder. Here, we investigated the association between coffee, green tea (another major source of caffeine), and caffeine, and bladder cancer incidence in relation to smoking status. We conducted a population-based prospective study in a cohort of Japanese, comprising a total of 49 566 men and 54 874 women aged 40–69 years who reported their coffee and green tea consumption at baseline. During follow-up from 1990 through 2005, 164 men and 42 women were newly diagnosed with bladder cancer. Cigarette smoking was associated with an increased risk of bladder cancer, with a strong dose–response relationship. Coffee was positively associated with bladder cancer risk in men, without statistical significance. When stratified by smoking status, coffee and caffeine consumption were associated with an increased risk of bladder cancer in never- or former-smoking men, with hazard ratios (95% confidence interval) in the highest categories of coffee (one or more cups per day) and caffeine consumption compared with the lowest of 2.24 (95% CI = 1.21–4.16) and 2.05 (95% CI = 1.15–3.66), respectively. In conclusion, cigarette smoking was confirmed as a risk factor for bladder cancer. Coffee and caffeine may be associated with an increased bladder cancer risk in never or former smokers among Japanese men.

Abundant in vitro and animal studies have shown a protective effect of green tea against various types of cancer, but the evidence from epidemiologic studies is inconclusive. In this nested case-control study, we used plasma biomarkers to directly investigate the effect of tea polyphenols on the risk of gastric cancer. Subjects were followed up from 1990 to 2004. Among 36,745 subjects who answered the baseline questionnaire and provided blood samples, 494 gastric cancer cases matched to 494 controls were used in the analysis. The validated method used high-performance liquid chromatography to analyze baseline plasma samples. For men, a high plasma level of (-)-epigallocatechin was associated with an increased risk of gastric cancer. For women, a high plasma level of (-)-epicatechin-3-gallate (ECG) was associated with a decreased risk of gastric cancer; the adjusted odds ratios (95% confidence intervals) for ECG levels 0.32 to 9.2 and 9.3+ ng/mL were 1.03 (0.41-2.59) and 0.25 (0.08-0.73), respectively, compared with those whose ECG level was under the detection limit (P for trend = 0.02). Cigarette smoking was suggested to play a role as an effect modifier, which explains in part the different patterns observed by gender.

The incidence of prostate cancer is much lower in Asian than Western populations. Given that environmental factors such as dietary habits may play a major role in the causation of prostate cancer and the high consumption of green tea in Asian populations, this low incidence may be partly due to the effects of green tea. The JPHC Study (Japan Public Health Center-based Prospective Study) was established in 1990 for cohort I and in 1993 for cohort II. The subjects were 49,920 men aged 40-69 years who completed a questionnaire that included their green tea consumption habit at baseline and were followed until the end of 2004. During this time, 404 men were newly diagnosed with prostate cancer, of whom 114 had advanced cases, 271 were localized, and 19 were of an undetermined stage. Green tea was not associated with localized prostate cancer. However, consumption was associated with a dose-dependent decrease in the risk of advanced prostate cancer. The multivariate relative risk was 0.52 (95% confidence interval: 0.28, 0.96) for men drinking 5 or more cups/day compared with less than 1 cup/day (p(trend) = 0.01). Green tea may be associated with a decreased risk of advanced prostate cancer.

Pancreatic cancer is one of the most aggressive and treatment-refractory malignancies in humans. The most effective means of reducing pancreatic cancer mortality may be primary prevention. Although laboratory studies have demonstrated that green tea possesses anticancer activities, results from epidemiological studies have failed to show a consistent cancer-preventive effect. In addition, there is a lingering concern that coffee mighty increase the risk of pancreatic cancer although the most recent epidemiological studies showed no overall association between coffee and risk. Here, we examined the association between the drinking of green tea or coffee and the risk of pancreatic cancer in a large population-based cohort study in Japan (JPHC study). In total, 102 137 participants were followed for an average of 11 years through to the end of 2003. A total of 233 incident cases of pancreatic cancer were identified among 1 116 945 person-years of follow-up. Overall, the risk of pancreatic cancer was not associated with either green tea or coffee intake in our population, although a reduced risk was apparent among men who drank at least three cups of coffee per day compared with those who did not drink any or only rarely drank coffee. In conclusion, our findings support the idea that green tea or coffee consumption does not have a substantial impact on pancreatic cancer risk in general.

Objective: To investigate the relationship between green tea consumption and subsequent risk of gastric cancer at different anatomical subsites in a population-based prospective study., Methods: The Japan Public Health Center-based prospective study (JPHC Study) was established in 1990 for Cohort I and in 1993 for Cohort II. Among 72,943 subjects (34,832 men and 38,111 women), 892 gastric cancer cases (665 men and 227 women) were identified from 1990 to 2001., Results: While no association between green tea consumption and gastric cancer was observed among men, a decreased risk of gastric cancer was observed among women after adjustment for potential confounding factors. This result was more remarkable when only the tumors in the distal portion were analyzed; for that subsite, the relative risk was 0.51 (95% confidence interval 0.30-0.86) in the highest category of green tea consumption (5 or more cups per day versus less than 1 cup per day) (p for trend = 0.01). The null association for upper-third gastric cancer was consistent for both sexes., Conclusions: An inverse association between green tea consumption and distal gastric cancer was observed among women. More prospective studies with detailed information are needed to confirm the role of green tea in the occurrence of gastric cancer., (Copyright 2004 Kluwer Academic Publishers)

Purpose: To examine the relation between green tea consumption and arteriographically determined coronary atherosclerosis., Methods: Study subjects were 512 patients (302 men and 210 women) aged 30 years or older who underwent coronary arteriography for the first time at four hospitals in Fukuoka City or one hospital in an adjacent city between September 1996 and August 1997. Lifestyle characteristics including green tea consumption were ascertained before arteriography by a questionnaire supported with interview., Results: 117 men (38.7%) and 50 women (23.8%) had significant stenosis of one or more coronary arteries. Green tea consumption tended to be inversely associated with coronary atherosclerosis in men, but not in women. An evident, protective association between green tea and coronary atherosclerosis was observed in a subgroup of 262 men excluding those under dietary or drug treatment for diabetes mellitus. In this subgroup, after adjustment for traditional coronary risk factors and coffee, odds ratios of significant stenosis for consumption of 2-3 cups and 4 or more cups per day were 0.5 (95% confidence interval 0.2-1.2) and 0.4 (0.2-0.9), respectively, as compared with a consumption of one cup per day or less., Conclusions: The results indicate that green tea may be protective against coronary atherosclerosis at least in men.