Coffee consumption and risk of cancers: a meta-analysis of cohort studies

[The psychological effects of taking in "Shikohin": A cross-sectional exploratory study]

This study explores the psychological effects that Japanese people experience when consuming their "Shikohin", such as alcohol, tea, coffee, and tobacco. We'conducted a cross-sectional study among 542 people, from 20-to 69-year-old; who regularly consumed any one of "Shikohin" in Tokyo, Kanagawa, Saitama, and Chiba. The participants responded to an anonymous questionnaire concerning the consumption patterns of their "Shikohin" and the psychological effects that they experienced in taking in their "Shikohin". Results obtained using the K-J methods showed three common psychological effects in each "Shikohin". These effects included an increase in relaxation response, the promotion of social relationships, and an increase in positive mood. Our findings suggest that Japanese people may get some common effects through consumption of different "Shikohin".

Coffee consumption and risk of endometrial cancer: a dose-response meta-analysis of prospective cohort studies

This is a dose-response (DR) meta-analysis to evaluate the association of coffee consumption on endometrial cancer (EC) risk. A total 1,534,039 participants from 13 published articles were added in this meta-analysis. The RR of total coffee consumption and EC were 0.80 (95% CI: 0.74–0.86). A stronger association between coffee intake and EC incidence was found in patients who were never treated with hormones, 0.60 (95% CI: 0.50–0.72), and subjects with a BMI ≥25 kg/m², 0.57 (95% CI: 0.46–0.71). The overall RRs for caffeinated and decaffeinated coffee were 0.66 (95% CI: 0.52–0.84) and 0.77 (95% CI: 0.63–0.94), respectively. A linear DR relationship was seen in coffee, caffeinated coffee, decaffeinated coffee and caffeine intake. The EC risk decreased by 5% for every 1 cup per day of coffee intake, 7% for every 1 cup per day of caffeinated coffee intake, 4% for every 1 cup per day of decaffeinated intake of coffee, and 4% for every 100 mg of caffeine intake per day. In conclusion, coffee and intake of caffeine might significantly reduce the incidence of EC, and these effects may be modified by BMI and history of hormone therapy.

Coffee Intake, Recurrence, and Mortality in Stage III Colon Cancer: Results From CALGB 89803 (Alliance)

PURPOSE

Observational studies have demonstrated increased colon cancer recurrence in states of relative hyperinsulinemia, including sedentary lifestyle, obesity, and increased dietary glycemic load. Greater coffee consumption has been associated with decreased risk of type 2 diabetes and increased insulin sensitivity. The effect of coffee on colon cancer recurrence and survival is unknown.

PATIENTS AND METHODS

During and 6 months after adjuvant chemotherapy, 953 patients with stage III colon cancer prospectively reported dietary intake of caffeinated coffee, decaffeinated coffee, and nonherbal tea, as well as 128 other items. We examined the influence of coffee, nonherbal tea, and caffeine on cancer recurrence and mortality using Cox proportional hazards regression.

RESULTS

Patients consuming 4 cups/d or more of total coffee experienced an adjusted hazard ratio (HR) for colon cancer recurrence or mortality of 0.58 (95% CI, 0.34 to 0.99), compared with never drinkers (Ptrend = .002). Patients consuming 4 cups/d or more of caffeinated coffee experienced significantly reduced cancer recurrence or mortality risk compared with abstainers (HR, 0.48; 95% CI, 0.25 to 0.91; Ptrend = .002), and increasing caffeine intake also conferred a significant reduction in cancer recurrence or mortality (HR, 0.66 across extreme quintiles; 95% CI, 0.47 to 0.93; Ptrend = .006). Nonherbal tea and decaffeinated coffee were not associated with patient outcome. The association of total coffee intake with improved outcomes seemed consistent across other predictors of cancer recurrence and mortality.

CONCLUSION

Higher coffee intake may be associated with significantly reduced cancer recurrence and death in patients with stage III colon cancer.

Dietary phenolics against colorectal cancer--From promising preclinical results to poor translation into clinical trials: Pitfalls and future needs

Colorectal cancer (CRC) remains a major cause of cancer death worldwide. Over 70% of CRC cases are sporadic and related to lifestyle. Epidemiological studies inversely correlate CRC incidence with the intake of fruits and vegetables but not with their phenolic content. Preclinical studies using in vitro (cell lines) and animal models of CRC have reported anticancer effects for dietary phenolics through the regulation of different markers and signaling pathways. Herein, we review and contrast the evidence between preclinical studies and clinical trials (patients with CRC or at risk, familial adenopolyposis or aberrant crypt foci) investigating the protective effects of curcumin, resveratrol, isoflavones, green tea extracts (epigallocatechin gallate), black raspberry powder (anthocyanins and ellagitannins), bilberry extract (anthocyanins), ginger extracts (gingerol derivatives), and pomegranate extracts (ellagitannins and ellagic acid). To date, curcumin is the most promising polyphenol as possible future adjuvant in CRC management. Overall, the clinical evidence of dietary phenolics against CRC is still weak and the amounts needed to exert some effects largely exceed common dietary doses. We discuss here the possible reasons behind the gap between preclinical and clinical research (inconsistence of results, lack of clinical endpoints, etc.), and provide an outlook and a roadmap to approach this topic.

Nutriepigenomics: the role of nutrition in epigenetic control of human diseases

PURPOSE OF REVIEW

Nutrients or even diets affect the epigenome by lifelong remodeling. Nutritional imbalances are associated with noncommunicable diseases. Thus, nutriepigenomics is a promising field in the treatment of complex human diseases.

RECENT FINDINGS

The epigenome is susceptible to changes and can be shaped by nutritional states, especially in prenatal period through transgenerational mechanisms and in early postnatal life when critical developmental processes are taking place. Although more stable, the epigenetic marks in adulthood are also dynamic and modifiable by environmental factors including diet.

SUMMARY

The present review is focused on the most recent knowledge of epigenetically active nutrients/diets including transgenerational inheritance and prenatal predispositions related to increased risk for cancer, metabolic syndrome, and neurodegenerative diseases.

Consumption of hot beverages and foods and the risk of esophageal cancer: a meta-analysis of observational studies

Background

Previous studies have mostly focused on the effects of specific constituents of beverages and foods on the risk of esophageal cancer (EC). An increasing number of studies are now emerging examining the health consequences of the high temperature of beverages and foods. We conducted a meta-analysis to summarize the evidence and clarify the association between hot beverages and foods consumption and EC risk.

Methods

We searched the PubMed, Embase, and Web of Science databases for relevant studies, published before May 1, 2014, with the aim to estimate the association between hot beverage and food consumption and EC risk. A random-effect model was used to pool the results from the included studies. Publication bias was assessed by using the Begg test, the Egger test, and funnel plot.

Results

Thirty-nine studies satisfied the inclusion criteria, giving a total of 42,475 non-overlapping participants and 13,811 EC cases. Hot beverage and food consumption was significantly associated with EC risk, with an odds ratio (OR) of 1.82 (95% confidence interval [CI], 1.53–2.17). The risk was higher for esophageal squamous cell carcinoma, with a pooled OR of 1.60 (95% CI, 1.29–2.00), and was insignificant for esophageal adenocarcinoma (OR: 0.79; 95% CI: 0.53–1.16). Subgroup analyses suggests that the association between hot beverage and food consumption and EC risk were significant in Asian population (OR: 2.06; 95% CI: 1.62-2.61) and South American population (OR: 1.52; 95% CI: 1.25-1.85), but not significant in European population (OR: 0.95; 95% CI: 0.68-1.34).

Conclusions

Hot beverage and food consumption is associated with a significantly increased risk of EC, especially in Asian and South American populations, indicating the importance in changing people’s dietary habits to prevent EC.

Serum biomarkers of habitual coffee consumption may provide insight into the mechanism underlying the association between coffee consumption and colorectal cancer

BACKGROUND

Coffee intake may be inversely associated with colorectal cancer; however, previous studies have been inconsistent. Serum coffee metabolites are integrated exposure measures that may clarify associations with cancer and elucidate underlying mechanisms.

OBJECTIVES

Our aims were 2-fold as follows: 1) to identify serum metabolites associated with coffee intake and 2) to examine these metabolites in relation to colorectal cancer.

DESIGN

In a nested case-control study of 251 colorectal cancer cases and 247 matched control subjects from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, we conducted untargeted metabolomics analyses of baseline serum by using ultrahigh-performance liquid-phase chromatography-tandem mass spectrometry and gas chromatography-mass spectrometry. Usual coffee intake was self-reported in a food-frequency questionnaire. We used partial Pearson correlations and linear regression to identify serum metabolites associated with coffee intake and conditional logistic regression to evaluate associations between coffee metabolites and colorectal cancer.

RESULTS

After Bonferroni correction for multiple comparisons (P = 0.05 ÷ 657 metabolites), 29 serum metabolites were positively correlated with coffee intake (partial correlation coefficients: 0.18-0.61; P < 7.61 × 10(-5)); serum metabolites most highly correlated with coffee intake (partial correlation coefficients >0.40) included trigonelline (N'-methylnicotinate), quinate, and 7 unknown metabolites. Of 29 serum metabolites, 8 metabolites were directly related to caffeine metabolism, and 3 of these metabolites, theophylline (OR for 90th compared with 10th percentiles: 0.44; 95% CI: 0.25, 0.79; P-linear trend = 0.006), caffeine (OR for 90th compared with 10th percentiles: 0.56; 95% CI: 0.35, 0.89; P-linear trend = 0.015), and paraxanthine (OR for 90th compared with 10th percentiles: 0.58; 95% CI: 0.36, 0.94; P-linear trend = 0.027), were inversely associated with colorectal cancer.

CONCLUSIONS

Serum metabolites can distinguish coffee drinkers from nondrinkers; some caffeine-related metabolites were inversely associated with colorectal cancer and should be studied further to clarify the role of coffee in the cause of colorectal cancer. The Prostate, Lung, Colorectal, and Ovarian trial was registered at clinicaltrials.gov as NCT00002540.

Prospective study of breast cancer in relation to coffee, tea and caffeine in Sweden

Studies of coffee and tea consumption and caffeine intake as risk factors for breast cancer are inconclusive. We assessed coffee and tea consumption, caffeine intake, and possible confounding factors among 42,099 women from the Swedish Women's Lifestyle and Health study, the participants of which were aged 30-49 years at enrollment in 1991-1992. Complete follow-up for breast cancer incidence was performed through 2012 via linkage to national registries. Poisson regression models were used to estimate relative risks (RRs) and 95% confidence intervals (CIs) for breast cancer. During follow-up 1,395 breast cancers were diagnosed. The RR was 0.97 (95% CI 0.94-0.99) for a 1-unit increase in cups of coffee/day, 1.14 (95% CI 1.05-1.24) for a 1-unit increase in cups of tea/day, and 0.97 (95% CI 0.95-1.00) for a 100 mg/day increase in caffeine intake. Although the RR for no consumption (RR = 0.86, 95% CI 0.69-1.08), a group with a relatively small number of women, was not statistically significant, women with higher consumption had a decreased breast cancer risk (3-4 cups/day: RR = 0.87, 95% CI 0.76-1.00; ≥5 cups/day: RR = 0.81, 95% CI 0.70-0.94) compared to women consuming 1-2 cups of coffee/day. Compared to no consumption, women consuming >1 cups tea/day showed an increased breast cancer risk (RR = 1.19, 95% CI 1.00-1.42). Similar patterns of estimates were observed for breast cancer risk overall, during pre- and postmenopausal years, and for ER+ or PR+ breast cancer, but not for ER- and PR- breast cancer. Our findings suggest that coffee consumption and caffeine intake is negatively associated with the risk of overall and ER+/PR- breast cancer, and tea consumption is positively associated with the risk of overall and ER+/PR+ breast cancer.

The Cytotoxicity of Kahweol in HT-29 Human Colorectal Cancer Cells Is Mediated by Apoptosis and Suppression of Heat Shock Protein 70 Expression

Although coffee is known to have antioxidant, anti-inflammatory, and antitumor properties, there have been few reports about the effect and mechanism of coffee compounds in colorectal cancer. Heat shock proteins (HSPs) are molecular chaperones that prevent cell death. Their expression is significantly elevated in many tumors and is accompanied by increased cell proliferation, metastasis and poor response to chemotherapy. In this study, we investigated the cytotoxicity of four bioactive compounds in coffee, namely, caffeine, caffeic acid, chlorogenic acid, and kahweol, in HT-29 human colon adenocarcinoma cells. Only kahweol showed significant cytotoxicity. Specifically, kahweol increased the expression of caspase-3, a pro-apoptotic factor, and decreased the expression of anti-apoptotic factors, such as Bcl-2 and phosphorylated Akt. In addition, kahweol significantly attenuated the expression of HSP70. Inhibition of HSP70 activity with triptolide increased kahweol-induced cytotoxicity. In contrast, overexpression of HSP70 significantly reduced kahweol-induced cell death. Taken together, these results demonstrate that kahweol inhibits colorectal tumor cell growth by promoting apoptosis and suppressing HSP70 expression.

Coffee consumption and prostate cancer risk: a meta-analysis of cohort studies

This meta-analysis was conducted to assess the association between coffee consumption and prostate cancer risk. Thirteen cohort studies with 34,105 cases and 539,577 participants were included in the meta-analysis. The summary relative risks (RRs) with 95% confidence intervals (CIs) for different coffee intake levels were calculated. Dose-response relationship was assessed using generalized least square trend estimation. The pooled RR for the highest vs. lowest coffee intake was 0.90 (95% CI: 0.85-0.95), with no significant heterogeneity across studies (P = 0.267; I(2) = 17.5%). The dose-response analysis showed a lower cancer risk decreased by 2.5% (RR = 0.975; 95% CI: 0.957-0.995) for every 2 cups/day increment in coffee consumption. Stratifying by geographic region, there was a statistically significant protective influence of coffee on prostate cancer risk among European populations. In subgroup analysis of prostate cancer grade, the summary RRs were 0.89 (95% CI: 0.83-0.96) for nonadvanced, 0.82 (95% CI: 0.61-1.10) for advanced and 0.76 (95% CI: 0.55-1.06) for fatal diseases. Our findings suggest that coffee consumption may be associated with a reduced risk of prostate cancer and it also has an inverse association with nonadvanced prostate cancer. Because of the limited number of studies, more prospective studies with large sample size are needed to confirm this association.

Tea, coffee, and caffeine and early-onset basal cell carcinoma in a case-control study

Tea and coffee are hypothesized to play a protective role in skin carcinogenesis through bioactive components, such as caffeine, yet the epidemiologic evidence is mixed. Existing data support an inverse association with basal cell carcinoma (BCC), more so than for melanoma or squamous cell carcinoma. To understand whether tea, coffee, and caffeine are related to early-onset BCC, we evaluated data from 767 non-Hispanic Whites under age 40 in a case-control study in Connecticut. BCC cases (n=377) were identified through Yale's Dermatopathology database. Controls (n=390) were randomly sampled from individuals in the same database with benign skin diagnoses and frequency matched to cases on age, sex, and biopsy site. Participants completed an in-person interview including assessment of caffeinated coffee and hot tea. We calculated multivariate odds ratios (ORs) and 95% confidence intervals (CIs) with unconditional logistic regression for regular consumption and frequency and duration measures. Combined regular consumption of caffeinated coffee plus hot tea was inversely associated with early-onset BCC (OR=0.60, 95% CI=0.38-0.96). Those in the highest category of caffeine from these sources had a 43% reduced risk of BCC compared with nonconsumers (OR=0.57, 95% CI=0.34-0.95, P-trend=0.037). Our findings suggest a modest protective effect for caffeinated coffee plus tea in relation to early-onset BCC that may, in part, be due to caffeine. This study adds to the growing body of literature suggesting potential health benefits from these beverages.

Boiled coffee consumption and the risk of prostate cancer: follow-up of 224,234 Norwegian men 20-69 years

BACKGROUND

There is insufficient epidemiological evidence on the relationship between type of coffee and the risk of prostate cancer.

METHODS

The risk of prostate cancer by use of boiled vs not boiled coffee were assessed in a prospective study of 224,234 men 20-69 years. 5740 incident prostate cancers were identified.

RESULTS

With no coffee as reference group the hazard ratios of <1-4, 5-8 and 9+ cups per day of boiled coffee only were 0.84 (0.73-0.96), 0.80 (0.70-0.92) and 0.66 (0.55-0.80), P-trend=0.00. The corresponding figures for not boiled coffee were 0.89 (0.80-0.99), 0.91 (0.81-1.02) and 0.86 (0.74-1.00), P-trend=0.22.

CONCLUSION

An inverse relationship between number of cups per day and the risk of prostate cancer was present only for the boiled coffee type.

Risk factors for pancreatic cancer: a summary review of meta-analytical studies

BACKGROUND

The aetiology of pancreatic cancer (PC) has been extensively studied and is the subject of numerous meta-analyses and pooled analyses. We have summarized results from these pooled and meta-analytical studies to estimate the fraction of PCs attributable to each of the identified risk factors.

METHODS

Using a comprehensive strategy, we retrieved 117 meta-analytical or pooled reports dealing with the association between specific risk factors and PC risk. We combined estimates of relative risk and estimates of exposure to calculate the fraction of PCs caused or prevented by a particular exposure.

RESULTS

Tobacco smoking ('strong' evidence) and Helicobacter pylori infection ('moderate' evidence) are the major risk factors associated with PC, with respective estimated population attributable fractions of 11-32% and 4-25%. The major protective factors are history of allergy ('strong' evidence) and increasing fruit or folate intake ('moderate' evidence), with respective population preventable fractions of 3-7% and 0-12%.

CONCLUSIONS

We summarized results of 117 meta-analytical or pooled data reports dealing with 37 aetiological exposures, to obtain robust information about the suspected causes of PC. By combining these estimates with their prevalences in the population, we calculated population attributable or population preventable fractions. About two-thirds of the major risk factors associated with PC are potentially modifiable, affording a unique opportunity for preventing one of our deadliest cancers.

Coffee and beverages are the major contributors to polyphenol consumption from food and beverages in Japanese middle-aged women

Food and beverages rich in polyphenols have been shown to reduce the risk of non-communicable diseases. The present study estimated polyphenol levels and consumption from food and beverages in Japanese women. Randomly recruited housewives living in the area around Tokyo (n 109; aged 21–56 years; Group 1) recorded all beverages and foods they ingested for 7 d, and the total polyphenol (TP) consumption was estimated based on the TP content of each item measured with a modified Folin–Ciocalteu method. For Group 1, TP was consumed at 841 (sd 403) mg/d (range 113–1759 mg/d), and beverages were a larger source of TP (79 %) than food (21 %). The largest single source of TP was coffee at 47 %, followed by green tea, black tea, chocolate, beer and soya sauce, at 16, 5·7, 3·3, 3·2 and 3·1 %, respectively. In terms of food groups, cereals/noodles, vegetables, fruits, beans and seeds, and seasonings (except for soya sauce) contributed 5·0, 4·0, 1·4, 1·8 and 2·4 %, respectively. Another group of housewives who consumed at least one cup of coffee per d were separately recruited (n 100; Group 2) in the same area. Their consumption of TP was higher at 1187 (sd 371) mg/d (range 440–2435 mg/d) than Group 1 (P < 0·001), and the difference mostly came from the coffee consumption. We conclude that not food but beverages, especially coffee, may be the major contributor to TP consumption in Japanese women.

Coffee consumption and mortality from all causes, cardiovascular disease, and cancer: a dose-response meta-analysis

Several studies have analyzed the relationship between coffee consumption and mortality, but the shape of the association remains unclear. We conducted a dose-response meta-analysis of prospective studies to examine the dose-response associations between coffee consumption and mortality from all causes, cardiovascular disease (CVD), and all cancers. Pertinent studies, published between 1966 and 2013, were identified by searching PubMed and by reviewing the reference lists of the selected articles. Prospective studies in which investigators reported relative risks of mortality from all causes, CVD, and all cancers for 3 or more categories of coffee consumption were eligible. Results from individual studies were pooled using a random-effects model. Twenty-one prospective studies, with 121,915 deaths and 997,464 participants, met the inclusion criteria. There was strong evidence of nonlinear associations between coffee consumption and mortality for all causes and CVD (P for nonlinearity < 0.001). The largest risk reductions were observed for 4 cups/day for all-cause mortality (16%, 95% confidence interval: 13, 18) and 3 cups/day for CVD mortality (21%, 95% confidence interval: 16, 26). Coffee consumption was not associated with cancer mortality. Findings from this meta-analysis indicate that coffee consumption is inversely associated with all-cause and CVD mortality.

Exposure to polycyclic aromatic hydrocarbons (PAHs) and bladder cancer: evaluation from a gene-environment perspective in a hospital-based case-control study in the Canary Islands (Spain)

BACKGROUND

Exposure to polycyclic aromatic hydrocarbons (PAHs) has been linked to bladder cancer.

OBJECTIVE

To evaluate the role of PAHs in bladder cancer, PAHs serum levels were measured in patients and controls from a case-control study.

METHODS

A total of 140 bladder cancer patients and 206 healthy controls were included in the study. Sixteen PAHs were analyzed from the serum of subjects by gas chromatography-mass spectrometry.

RESULTS

Serum PAHs did not appear to be related to bladder cancer risk, although the profile of contamination by PAHs was different between patients and controls: pyrene (Pyr) was solely detected in controls and chrysene (Chry) was exclusively detected in the cases. Phenanthrene (Phe) serum levels were inversely associated with bladder cancer (OR = 0·79, 95%CI = 0·64-0·99, P = 0·030), although this effect disappeared when the allelic distribution of glutathione-S-transferase polymorphisms of the population was introduced into the model (multinomial logistic regression test, P = 0·933). Smoking (OR = 3·62, 95%CI = 1·93-6·79, P<0·0001) and coffee consumption (OR = 1·73, 95%CI = 1·04-2·86, P = 0·033) were relevant risk factors for bladder cancer.

CONCLUSIONS

Specific PAH mixtures may play a relevant role in bladder cancer, although such effect seems to be highly modulated by polymorphisms in genes encoding xenobiotic-metabolizing enzymes.

Caffeic acid directly targets ERK1/2 to attenuate solar UV-induced skin carcinogenesis

Caffeic acid (3,4-dihydroxycinnamic acid) is a well-known phenolic phytochemical present in coffee and reportedly has anticancer activities. However, the underlying molecular mechanisms and targeted proteins involved in the suppression of carcinogenesis by caffeic acid are not fully understood. In this study, we report that caffeic acid significantly inhibits colony formation of human skin cancer cells and EGF-induced neoplastic transformation of HaCaT cells dose-dependently. Caffeic acid topically applied to dorsal mouse skin significantly suppressed tumor incidence and volume in a solar UV (SUV)-induced skin carcinogenesis mouse model. A substantial reduction of phosphorylation in mitogen-activated protein kinase signaling was observed in mice treated with caffeic acid either before or after SUV exposure. Caffeic acid directly interacted with ERK1/2 and inhibited ERK1/2 activities in vitro. Importantly, we resolved the cocrystal structure of ERK2 complexed with caffeic acid. Caffeic acid interacted directly with ERK2 at amino acid residues Q105, D106, and M108. Moreover, A431 cells expressing knockdown of ERK2 lost sensitivity to caffeic acid in a skin cancer xenograft mouse model. Taken together, our results suggest that caffeic acid exerts chemopreventive activity against SUV-induced skin carcinogenesis by targeting ERK1 and 2.

Coffee consumption and risk of gastric cancer: a large updated meta-analysis of prospective studies

The potential role of coffee consumption in the development of various types of cancer has been extensively investigated in epidemiologic studies. How coffee consumption may modulate risk of gastric cancer, however, remains a subject open for investigation. To better quantify this relation, we quantitatively summarized evidence from prospective studies. Eligible studies were identified on PubMed databases. The summary risk estimates were obtained using the random-effects model. Subgroup, sensitivity and dose-response analyses were conducted. The present meta-analysis included 12 prospective cohort studies. A pooled analysis of these studies suggested that coffee consumption (highest vs. lowest consumption) was not associated with risk of gastric cancer (RR = 1.12, 95% CI = 0.93–1.36). In the subgroup analysis, significant increased risk was detected in the U.S. studies (RR = 1.36, 95% CI = 1.06–1.74) and in the studies with <10 years of follow-up (RR = 1.24, 95% CI = 1.00–1.54), and the greatest increase in risk was observed in those studies without adjustment for smoking (RR = 1.48, 95% CI = 1.13–1.93). There was some evidence of publication bias (P for Egger’s test = 0.03). Cumulative evidence from prospective studies suggests that coffee consumption is not associated with risk of gastric cancer. The observed positive results may be confounded by smoking and need further investigation.

Endometrial cancer in relation to coffee, tea, and caffeine consumption: a prospective cohort study among middle-aged women in Sweden

This study aimed to add to prospective data on the possible inverse association between coffee consumption and endometrial cancer risk, already supported by several case-control studies. Coffee and tea consumption and possible confounding factors were assessed among 42,270 women aged 30-49 years at enrollment in 1991-1992 in the Swedish Women's Lifestyle and Health cohort study, with complete follow-up through 2009. We calculated caffeine intake per day; Cox proportional hazard models were used to estimate multivariable relative risks (mRR) for endometrial cancer with 95% confidence intervals (CIs). One hundred forty-four endometrial cancers were diagnosed during follow-up. Women with and without endometrial cancer had a similar mean daily coffee consumption (549 vs. 547 g), tea consumption (104 vs. 115 g), and caffeine intake (405 vs. 406 mg). Compared to those consuming <2 cups of coffee per day, women consuming >3 cups had a mRR of 1.56 (95% CI: 0.94-2.59; P for trend = 0.17). Compared with the lowest tertile of caffeine intake, the highest tertile had a mRR of 1.32 (95% CI: 0.87-1.99; P for trend = 0.27). Our study provides no convincing evidence of an association between coffee consumption, tea consumption, or caffeine intake and endometrial cancer risk among middle-aged women.

Association of coffee drinking with all-cause mortality: a systematic review and meta-analysis

OBJECTIVE

We aimed to use the meta-analysis method to assess the relationship between coffee drinking and all-cause mortality.

DESIGN

Categorical and dose-response meta-analyses were conducted using random-effects models.

SETTING

We systematically searched and identified eligible literature in the PubMed and Scopus databases.

SUBJECTS

Seventeen studies including 1 054 571 participants and 131 212 death events from all causes were included in the present study.

RESULTS

Seventeen studies were included and evaluated in the meta-analysis. A U-shaped dose-response relationship was found between coffee consumption and all-cause mortality (P for non-linearity <0.001). Compared with non/occasional coffee drinkers, the relative risks for all-cause mortality were 0.89 (95 % CI 0.85, 0.93) for 1-<3 cups/d, 0.87 (95 % CI 0.83, 0.91) for 3-<5 cups/d and 0.90 (95 % CI 0.87, 0.94) for ≥5 cups/d, and the relationship was more marked in females than in males.

CONCLUSIONS

The present meta-analysis of prospective cohort studies indicated that light to moderate coffee intake is associated with a reduced risk of death from all causes, particularly in women.

Patient-centered perspectives on the access to educational opportunities specific to lifestyle modification in men at risk for primary or secondary prostate cancer

Educating men at risk for primary or secondary prostate cancer on lifestyle modification may help prevent the development of the disease, reduce the risk of recurrence in those treated for cancer, and slow the progression of active disease. To date, substantial literature on male patient attitudes towards risk modification does not exist. In this project, we evaluate the attitudes and educational needs of men at high-risk for primary or secondary prostate cancer to assess the need for a dedicated clinic focused on education and prevention. Two clinic nurses administered surveys to 76 male patients seen at the University Kansas Cancer Center (KUCC) and Urology clinics. Survey responses showed the patients' perspectives and desire for more support and education regarding late effects of treatment, management of risk, and lifestyle modification. Findings from this survey inspired the establishment of the Burns & McDonnell High-Risk Prostate Cancer Prevention Program at KUCC.

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.

Habitual consumption of coffee and green tea in relation to serum adipokines: a cross-sectional study

PURPOSE

Coffee and green tea consumption may be associated with circulating adipokines, but data are inconsistent, scarce or lacking. We examined the association of coffee and green tea consumption with serum adiponectin, leptin, visfatin, resistin and plasminogen activator inhibitor-1 (PAI-1) among a Japanese working population.

METHODS

The authors analyzed data (n = 509) from a cross-sectional survey among Japanese workers aged 20-68 years. Serum adipokines were measured using a Luminex suspension bead-based multiplexed array. Coffee and green tea consumption was assessed using a validated diet history questionnaire, and caffeine consumption from these beverages was estimated. Multiple regression analysis was performed with adjustment for potential confounding variables.

RESULTS

Coffee consumption was significantly, inversely associated with leptin and PAI-1 (P for trend = 0.007 and 0.02, respectively); compared with subjects consuming <1 cup per day, those consuming ≥4 cups per day had 13 and 10 % lower means of leptin and PAI-1, respectively. Similar associations were observed for caffeine consumption (P for trend = 0.02 for both leptin and PAI-1). Additionally, we noted a significant positive association between coffee consumption and adiponectin in men (P for trend = 0.046), but not in women (P for trend = 0.43, P for interaction = 0.11). Moreover, there was a positive association between coffee consumption and resistin in current male smokers (P for trend = 0.01), but not in male non-smokers (P for trend = 0.35, P for interaction = 0.11). Green tea consumption was not associated with any adipokine.

CONCLUSIONS

Higher consumption of coffee and caffeine but not green tea was associated with lower serum levels of leptin and PAI-1 in Japanese adults.

Insights on the antitumor effects of kahweol on human breast cancer: decreased survival and increased production of reactive oxygen species and cytotoxicity

The present study aims to identify the modulatory effects of kahweol, an antioxidant diterpene present in coffee beans, on a panel of human tumor cell lines. Kahweol inhibits tumor cell proliferation and clonogenicity and induces apoptosis in several kinds of human tumor cells. In the estrogen receptor-negative MDA-MB231 human breast cancer, the mentioned effects are accompanied by caspases 3/7 and 9 activation and cytochrome c release. On the other hand, kahweol increases the production of reactive oxygen species and their cytotoxicity in human breast cancer cells but not in normal cells. Taken together, our data suggest that kahweol is an antitumor compound with inhibitory effects on tumor cell growth and survival, especially against MDA-MB231 breast cancer cells.

High coffee consumption and different brewing methods in relation to postmenopausal endometrial cancer risk in the Norwegian women and cancer study: a population-based prospective study

Background

Coffee and its compounds have been proposed to inhibit endometrial carcinogenesis. Studies in the Norwegian population can be especially interesting due to the high coffee consumption and increasing incidence of endometrial cancer in the country.

Methods

A total of 97 926 postmenopausal Norwegian women from the population-based prospective Norwegian Women and Cancer (NOWAC) Study, were included in the present analysis. We evaluated the general association between total coffee consumption and endometrial cancer risk as well as the possible impact of brewing method. Multivariate Cox regression analysis was used to estimate risks, and heterogeneity tests were performed to compare brewing methods.

Results

During an average of 10.9 years of follow-up, 462 incident endometrial cancer cases were identified. After multivariate adjustment, significant risk reduction was found among participants who drank ≥8 cups/day of coffee with a hazard ratio of 0.52 (95% confidence interval, CI 0.34-0.79). However, we did not observe a significant dose-response relationship. No significant heterogeneity in risk was found when comparing filtered and boiled coffee brewing methods. A reduction in endometrial cancer risk was observed in subgroup analyses among participants who drank ≥8 cups/day and had a body mass index ≥25 kg/m², and in current smokers.

Conclusions

These data suggest that in this population with high coffee consumption, endometrial cancer risk decreases in women consuming ≥8 cups/day, independent of brewing method.

Coffee consumption and prostate cancer risk: an updated meta-analysis

PURPOSE

Many epidemiological studies have been conducted to explore the association between coffee consumption and prostate cancer. However, the results remain inconsistent. We performed a large meta-analysis of relevant studies to derive a more precise estimation of this relationship.

METHODS

Systematic searches of PubMed and several other databases up to June 2013 were retrieved. All epidemiologic studies regarding coffee consumption and prostate cancer risk were included, and odds ratios (ORs) with 95 % confidence intervals (CIs) were calculated to estimate the strength of the association.

RESULTS

Twelve case-control studies involving 7,909 prostate cancer cases and 9,461 controls and nine cohort studies involving 455,123 subjects were included in our analysis. Compared with the lowest category, the unstratified highest category of coffee consumption showed a significance reduction in prostate cancer risk of a fixed-effects model (OR 0.91, CI 0.86-0.97). A borderline significant influence was also found when the stratified highest category (US ≥ 4, Europe ≥ 5) of coffee consumption was compared with the reference category (OR 0.96, CI 0.92-1.00), but no relationships were observed for the other two categories. In another analysis conducted by coffee consumption and prostate cancer stage and Gleason grade, our results showed a significant inverse association in all categories of prostate cancer except Gleason <7 grade in a fixed-effects model; the results remained the same, except for advanced prostate cancer, in a random-effects model.

CONCLUSIONS

Our meta-analysis suggests that high (e.g., highest ≥ 4 or 5 cups/day) coffee consumption may not only be associated with a reduced risk of overall prostate cancer, but also inversely associated with fatal and high-grade prostate cancer.

Coffee consumption and risk of nonaggressive, aggressive and fatal prostate cancer--a dose-response meta-analysis

BACKGROUND

Existing epidemiological evidence is controversial regarding the possible associations between coffee consumption and risk of prostate cancer (PCa) by aggressiveness of the disease.

MATERIALS AND METHODS

We conducted a random-effects dose-response meta-analysis to assess the relationships between coffee consumption and nonaggressive, aggressive and fatal PCa risk. Studies were identified by a search of Medline and Embase databases to 15 July 2013. We carried out separate analyses by grade (Gleason score: low-grade, high-grade) and stage (TNM staging system: localized, advanced) of the tumors. Nonaggressive tumors were defined as low-grade or localized, while aggressive tumors were defined as high-grade or advanced.

RESULTS

Eight studies (three case-control and five cohort) were included in this meta-analysis. Gleason 7 tumors were classified as high-grade in one study, while in another study, Gleason 7(4 + 3) tumors were classified as high-grade and Gleason 7(3 + 4) as low-grade. In the remaining four studies, Gleason 7 tumors were excluded from the analyses or analyzed separately. The pooled relative risk (RR) for a consumption increment of 3 cups/day was 0.97 [95% confidence interval (CI) 0.92-1.03] for low-grade PCa (n = 6), 0.97 (95% CI 0.94-0.99) for localized PCa (n = 6), 0.89 (95% CI 0.78-1.00) for high-grade PCa (n = 6), 0.95 (95% CI 0.85-1.06) for advanced PCa (n = 6) and 0.89 (95% CI 0.82-0.97) for fatal PCa (n = 4). No evidence of publication bias was observed. Heterogeneity was absent or marginal (I(2) range = 0-26%), with the only exception of the analysis on advanced PCa, where moderate heterogeneity was observed (I(2) = 60%). When restricting the analyses only to those studies that defined high-grade tumors as Gleason 8-10, the inverse association became slightly stronger [RR: 0.84 (95% CI 0.72-0.98); n = 4].

CONCLUSIONS

Results from this dose-response meta-analysis suggest that coffee consumption may be inversely associated with the risk of fatal PCa. No clear evidence of an association with PCa incidence was observed.

Report of the Japan Diabetes Society/Japanese Cancer Association Joint Committee on Diabetes and Cancer

In recent years, diabetes has been shown to be associated with cancer risk, and this has led to a joint committee being formed, enlisting experts from the Japan Diabetes Society and the Japanese Cancer Association to address this issue. Epidemiological data in Japan provides evidence to demonstrate that diabetes is associated with increased risk for cancers, especially colorectal, liver, and pancreatic cancers. The mechanisms through which diabetes is assumed to promote oncogenesis include insulin resistance and associated hyperinsulinemia, hyperglycemia, and inflammation. Common risk factors for type 2 diabetes and cancer include aging, male sex, obesity, physical inactivity, inappropriate diet (excessive red/processed meat intake, inadequate vegetable/fruit/dietary fiber intake), excessive alcohol drinking, and smoking. Given that inappropriate diet/exercise, smoking and excessive alcohol drinking are common risk factors for diabetes and cancer, diet/exercise therapy, smoking cessation and alcohol moderation may be associated with decreased risk for cancer in diabetic patients. There is as yet limited evidence as to whether any particular antidiabetic agents may influence cancer risk.

Lifestyle and dietary factors in prostate cancer prevention

The etiology of prostate cancer (PCa) is still largely unknown and the only well-established risk factors are those that are non-modifiable (age, race, and family history). Therefore, the identification of lifestyle and dietary factors which might prevent PCa development and progression is of paramount importance from a public health point of view. Accumulating evidence indicates that obesity may have a dual effect on PCa: an increased risk of aggressive PCa and a decreased risk of localized PCa. Both occupational and leisure time physical activity have been observed to be associated with a reduced PCa risk. Different dietary factors including coffee have been examined in several epidemiological studies, but results have been mostly inconsistent. However, these inconsistencies can be, at least partly, explained by the fact that the majority of those studies examined total PCa risk only and, in addition, they did not take into account the different genetic characteristics within the study populations. Therefore, the future epidemiological studies should focus on the analysis of PCa subtypes separately in order to examine possible etiological heterogeneity of PCa in relation to some exposures. In addition, differences in the genetic characteristics of the study participants should be taken into account to explore the possibility of gene-environment interactions.

Coffee and green tea consumption is associated with upper aerodigestive tract cancer in Japan

The impact of coffee and green tea consumption on upper aerodigestive tract (UADT) cancer risk has not been established. Evaluation of the possible anticarcinogenic properties of their ingredients is confounded by the potential increase in risk owing to the high temperatures at which these beverages are generally consumed. We conducted a case-control study to evaluate the association between coffee and tea consumption and the risk of UADT cancer. The study enrolled 961 patients with UADT cancer and 2,883 noncancer outpatients who visited Aichi Cancer Center between 2001 and 2005. Information on coffee and green tea consumption and other lifestyle factors was collected via a self-administered questionnaire. Consumption of three or more cups of coffee per day had a significant inverse association with UADT cancer [odds ratio (OR) 0.73, 95% confidence interval (CI) 0.55-0.96]. In contrast, consumption of three or more cups of green tea per day had a significant positive association with UADT cancer (OR 1.39, 95% CI 1.13-1.70). These associations were evident for head and neck cancer but not for esophageal cancer. The association of coffee consumption with head and neck cancer was observed only among never smokers and alcohol drinkers. Similarly, the association of green tea consumption was observed among never smokers and never alcohol drinkers. No change in these associations was seen on stratification by each confounding factors. These findings suggest that consumption of coffee might be associated with a decreased risk of UADT cancer, whereas that of green tea might be associated with an increased risk.

Coffee consumption and risk of prostate cancer: an up-to-date meta-analysis

BACKGROUND/OBJECTIVES

Epidemiologic findings concerning the association between coffee consumption and prostate cancer risk yielded mixed results. We aimed to investigate the association by performing a meta-analysis of all available studies.

SUBJECTS/METHODS

We searched PubMed, Web of Science and EMBASE for studies published up to July 2013. We calculated the summary relative risk (RR) and 95% confidence intervals (CIs) for ever, moderate and highest consumption of coffee vs non/lowest consumption. The dose-response relationship was assessed by restricted cubic spline model and multivariate random-effect meta-regression.

RESULTS

A total of 12 case-control studies and 12 cohort studies with 42,179 cases were selected for final meta-analysis. No significant associations were found among overall analysis. A borderline positive association was found for highest drinkers in five small hospital-based case-control (HCC) studies involving 2278 cases. However, compared with non/lowest drinkers, the summary RRs were 0.92 (95% CI=0.85-0.99) for ever drinkers, 0.92 (95% CI=0.85-1.00) for moderate drinkers and 0.83 (95% CI=0.72-0.96) for highest drinkers from 12 cohort studies, comprising a total of 34,424 cases. An increase in coffee intake of two cups/day was associated with a 7% decreased risk of prostate cancer according to cohort studies. A significant inverse relationship was also found for fatal prostate cancers and high-grade prostate cancers.

CONCLUSIONS

Case-control studies especially HCC ones might be prone to selection bias and recall bias that might have contributed to the conflicting results. Therefore, the present meta-analysis suggests a borderline significant inverse association between coffee consumption and prostate cancer risk based on cohort studies.

Diet and supplements and their impact on colorectal cancer

BACKGROUND

Colorectal cancer is the third commonest cancer and the third leading cause of cancer death among men and women. It has been proposed that dietary factors are responsible for 70-90% of colorectal cancer and diet optimization may prevent most cases.

AIM

To evaluate the role of dietary components and supplements in colorectal cancer.

METHODS

Bibliographical searches were performed in Pubmed for the terms "diet and colorectal cancer", "diet and colon cancer", "diet and rectal cancer", "nutrition and colorectal cancer", "probiotics and colorectal cancer", "prebiotics and colorectal cancer", "alcohol and cancer" and "colorectal cancer epidemiology".

RESULTS

Consumption of processed or red meat, especially when cooked at high temperatures may be associated with increased risk of colorectal cancer. The evidence for dietary fibre is unclear but foods that contain high amounts of fibre are usually rich in polyphenols which have been shown to alter molecular processes that can encourage colorectal carcinogenesis. Meta-analyses provide evidence on the benefits of circulating, diet-derived and supplemented, vitamin D and Calcium. We also found that diets rich in Folate may prevent colorectal carcinoma. The evidence on dietary micronutrients such as Zinc and Selenium in association with colorectal cancer is not conclusive. It has been suggested that there may be a direct association between alcohol intake and colorectal cancer. In vitro and in vivo studies have highlighted a possible protective role of prebiotics and probiotics.

CONCLUSIONS

The lack of randomized trials and the presence of confounding factors including smoking, physical activity, obesity and diabetes may often yield inconclusive results. Carefully designed randomized trials are recommended.

Coffee consumption and total mortality: a meta-analysis of twenty prospective cohort studies

Coffee consumption has been shown to be associated with various health outcomes, but no comprehensive review and meta-analysis of the association between coffee consumption and total mortality has been conducted. To quantitatively assess this association, we conducted a meta-analysis of prospective cohort studies. Eligible studies were identified by searching the PubMed and EMBASE databases for all articles published through June 2013 and reviewing the reference lists of the retrieved articles. Pooled relative risks (RR) with 95% CI were calculated using a random-effects model. We identified twenty studies of coffee consumption and total mortality, including 129,538 cases of deaths among the 973,904 participants. The RR of total mortality for the high v. low category of coffee consumption was 0.86 (95% CI 0.80, 0.92). The pooled RR for studies using ≥ 2-4 cups/d as a cut-off for the high category was similar to that for studies using ≥ 5-9 cups/d as the cut-off. By geographical region, the inverse association tended to be stronger for the eight studies conducted in Europe (RR 0.78, 95% CI 0.70, 0.88) and three studies carried out in Japan (RR 0.82, 95% CI 0.73, 0.92) than for the nine studies conducted in the USA (RR 0.92, 95% CI 0.84, 1.00). The inverse association was similar for men (RR 0.81, 95% CI 0.73, 0.90) and women (RR 0.84, 95% CI 0.79, 0.89). A weak, but significant, inverse association was found with moderate coffee consumption (1-2 cups/d; RR 0.92, 95% CI 0.87, 0.98). High decaffeinated coffee consumption was also found to be associated with a lower risk of death, but the data are limited. Our findings indicate that coffee consumption is associated with a reduced risk of total mortality.

A meta-analysis of prospective studies of coffee consumption and mortality for all causes, cancers and cardiovascular diseases

Several prospective studies considered the relation between coffee consumption and mortality. Most studies, however, were underpowered to detect an association, since they included relatively few deaths. To obtain quantitative overall estimates, we combined all published data from prospective studies on the relation of coffee with mortality for all causes, all cancers, cardiovascular disease (CVD), coronary/ischemic heart disease (CHD/IHD) and stroke. A bibliography search, updated to January 2013, was carried out in PubMed and Embase to identify prospective observational studies providing quantitative estimates on mortality from all causes, cancer, CVD, CHD/IHD or stroke in relation to coffee consumption. A systematic review and meta-analysis was conducted to estimate overall relative risks (RR) and 95 % confidence intervals (CI) using random-effects models. The pooled RRs of all cause mortality for the study-specific highest versus low (≤1 cup/day) coffee drinking categories were 0.88 (95 % CI 0.84-0.93) based on all the 23 studies, and 0.87 (95 % CI 0.82-0.93) for the 19 smoking adjusting studies. The combined RRs for CVD mortality were 0.89 (95 % CI 0.77-1.02, 17 smoking adjusting studies) for the highest versus low drinking and 0.98 (95 % CI 0.95-1.00, 16 studies) for the increment of 1 cup/day. Compared with low drinking, the RRs for the highest consumption of coffee were 0.95 (95 % CI 0.78-1.15, 12 smoking adjusting studies) for CHD/IHD, 0.95 (95 % CI 0.70-1.29, 6 studies) for stroke, and 1.03 (95 % CI 0.97-1.10, 10 studies) for all cancers. This meta-analysis provides quantitative evidence that coffee intake is inversely related to all cause and, probably, CVD mortality.

The association of coffee intake with liver cancer incidence and chronic liver disease mortality in male smokers

Background:

Coffee intake is associated with reduced risk of liver cancer and chronic liver disease as reported in previous studies, including prospective ones conducted in Asian populations where hepatitis B viruses (HBVs) and hepatitis C viruses (HCVs) are the dominant risk factors. Yet, prospective studies in Western populations with lower HBV and HCV prevalence are sparse. Also, although preparation methods affect coffee constituents, it is unknown whether different methods affect disease associations.

Methods:

We evaluated the association of coffee intake with incident liver cancer and chronic liver disease mortality in 27 037 Finnish male smokers, aged 50–69, in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study, who recorded their coffee consumption and were followed up to 24 years for incident liver cancer or chronic liver disease mortality. Multivariate relative risks (RRs) and 95% confidence intervals (CIs) were estimated by Cox proportional hazard models.

Results:

Coffee intake was inversely associated with incident liver cancer (RR per cup per day=0.82, 95% CI: 0.73–0.93; P-trend across categories=0.0007) and mortality from chronic liver disease (RR=0.55, 95% CI: 0.48–0.63; P-trend<0.0001). Inverse associations persisted in those without diabetes, HBV- and HCV-negative cases, and in analyses stratified by age, body mass index, alcohol and smoking dose. We observed similar associations for those drinking boiled or filtered coffee.

Conclusion:

These findings suggest that drinking coffee may have benefits for the liver, irrespective of whether coffee was boiled or filtered.

Coffee and risk of prostate cancer incidence and mortality in the Cancer of the Prostate in Sweden Study

PURPOSE

Coffee intake has recently been associated with significantly lower risk of lethal and advanced prostate cancer in a US population.

METHODS

We studied the association between coffee and prostate cancer risk in the population-based case-control study Cancer of the Prostate in Sweden. Dietary data were available for 1,499 cases and 1,112 controls. We calculated odds ratios (ORs) for the risk of prostate cancer in high versus low categories of coffee intake using logistic regression. We studied overall prostate cancer risk as well as risk of fatal, advanced, localized, high-grade, grade 7, and low-grade disease.

RESULTS

Mean coffee intake was 3.1 cups per day among both cases and controls. Coffee intake was not associated with overall prostate cancer risk. Risk of fatal prostate cancer was inversely, but not statistically significantly, associated with coffee intake, with an odds ratio of 0.64 [95 % confidence interval (CI) 0.34-1.19, p value for linear trend = 0.81] for men consuming greater than 5 cups per day compared to men drinking less than 1 cup per day. The highest intake of coffee was associated non-significantly with lower risk of advanced disease (OR = 0.73, 95 % CI 0.41-1.30, p trend = 0.98) and associated significantly with lower risk of high-grade cancer (Gleason 8-10; OR = 0.50, 95 % CI 0.26-0.98, p trend = 0.13). Risk of localized, grade 7, and low-grade cancers was not associated with coffee intake.

CONCLUSIONS

This study provides some support of an inverse association between coffee and lethal and high-grade prostate cancer.

Coffee consumption and the risk of overall and fatal prostate cancer in the NIH-AARP Diet and Health Study

PURPOSE

Evidence on the association between coffee consumption and prostate cancer risk is inconsistent; furthermore, few studies have examined the relationship between coffee consumption and fatal prostate cancer. The aim of this study was to investigate whether coffee intake is associated with the risk of overall and fatal prostate cancer.

METHODS

We conducted a prospective analysis among 288,391 men in the National Institutes of Health AARP Diet and Health Study who were between 50 and 71 years old at baseline in 1995-1996. Coffee consumption was assessed at baseline. Cox proportional hazards models were used to calculate the age- and multivariable-adjusted hazard ratios (HR)s and 95 % confidence intervals (CIs).

RESULTS

Over 11 years of follow-up, 23,335 cases of prostate cancer were ascertained, including 2,927 advanced and 917 fatal cases. Coffee consumption was not significantly associated with prostate cancer risk. The multivariable-adjusted HRs (95 % CI), comparing those who drank six or more cups per day to nondrinker, were as follows: 0.94 (0.86-1.02), p trend = 0.08 for overall prostate cancer, 1.13 (0.91-1.40), p trend = 0.62 for advanced prostate cancer, and 0.79 (0.53-1.17), p trend = 0.20 for fatal prostate cancer. The findings remained nonsignificant when we stratified by prostate-specific antigen testing history or restricted to nonsmokers.

CONCLUSIONS

We found no statistically significant association between coffee consumption and the risk of overall, advanced, or fatal prostate cancer in this cohort, though a modest reduction in risk could not be excluded.

Coffee consumption and the risk of prostate cancer: the Ohsaki Cohort Study

Background:

Epidemiological evidence regarding the effect of coffee on the incidence of prostate cancer is inconsistent. We aimed to investigate coffee consumption and the risk of prostate cancer risk in a general Japanese population.

Methods:

We conducted a prospective cohort study in Ohsaki city, Japan, where 18 853 men aged 40–79 years participated in a baseline survey. Coffee consumption was assessed via a validated self-administered questionnaire. During 11 years of follow-up (from January 1 1995 to December 31, 2005), 318 incident cases of prostate cancer were detected. The Cox proportional hazards regression model was used to calculate the hazard ratios (HRs) and 95% confidence interval (CIs).

Results:

There was a significant inverse association between coffee consumption and the incidence risk of prostate cancer. Compared with those who did not drink coffee, the multivariate adjusted HRs were 0.81 (95% CI: 0.61–1.07), 0.73 (95% CI: 0.53–1.00), and 0.63 (095% CI: 0.39–1.00) for those who drank coffee occasionally, 1–2 cups per day, and ⩾3 cups per day, respectively, with a P for trend of 0.02.

Conclusion:

This prospective finding from a Japanese population adds evidence that coffee intake is inversely associated with the incidence of prostate cancer.