The association between personal habits and bladder cancer in Turkey

Exploring the casual association between coffee intake and bladder cancer risk using Mendelian Randomization

Objective: Several observational studies have suggested that coffee consumption is associated with a lower risk of bladder cancer. However, observational studies are susceptible to confounding factors and reverse causality. We used a two-sample Mendelian randomization (MR) method to assess the causal nature of this association. Methods: At the genome-wide significance level (p < 5 × 10^-8), 12 single nucleotide polymorphisms (SNPs) strongly associated with coffee consumption were used as instrumental variables (IVs). Summary-level data on genetic variation in bladder cancer were obtained from the United Kingdom biobank (420,838 samples) and FinnGen consortium (175,121 samples). Multiple MR methods were used. Heterogeneity and horizontal pleiotropy were detected using Cochran's Q test and MR-Egger. Results: Twelve SNPs were included in the primary analysis. After excluding 8 SNPs with potential secondary phenotypes, the remaining 4 SNPs were included in the sensitivity analysis. In all analyses, Cochran's Q statistic indicated that there was no heterogeneity among SNPs, and the MR-Egger analysis did not reveal the existence of horizontal pleiotropy (p > 0.05). In the United Kingdom Biobank, the odds ratio (OR) for bladder cancer was 1.022 (95% confidence interval (CI), 0.679-1.537) for per 50% increase in coffee consumption. Consistent results were obtained in the FinnGen consortium (OR = 0.890, 95% CI, 0.467-1.697). Sensitivity analysis showed consistent results with primary analysis. Conclusion This study does not support a causal association between habitual coffee consumption and bladder cancer risk.

Coffee consumption and risk of bladder cancer: a pooled analysis of 501,604 participants from 12 cohort studies in the BLadder Cancer Epidemiology and Nutritional Determinants (BLEND) international study

Recent epidemiological studies have shown varying associations between coffee consumption and bladder cancer (BC). This research aims to elucidate the association between coffee consumption and BC risk by bringing together worldwide cohort studies on this topic. Coffee consumption in relation to BC risk was examined by pooling individual data from 12 cohort studies, comprising of 2601 cases out of 501,604 participants. Pooled multivariate hazard ratios (HRs), with corresponding 95% confidence intervals (CIs), were obtained using multilevel Weibull regression models. Furthermore, dose-response relationships were examined using generalized least squares regression models. The association between coffee consumption and BC risk showed interaction with sex (P-interaction < 0.001) and smoking (P-interaction = 0.001). Therefore, analyses were stratified by sex and smoking. After adjustment for potential confounders, an increased BC risk was shown for high (> 500 ml/day, equivalent to > 4 cups/day) coffee consumption compared to never consumers among male smokers (current smokers: HR = 1.75, 95% CI 1.27-2.42, P-trend = 0.002; former smokers: HR = 1.44, 95% CI 1.12-1.85, P-trend = 0.001). In addition, dose-response analyses, in male smokers also showed an increased BC risk for coffee consumption of more than 500 ml/day (4 cups/day), with the risk of one cup (125 ml) increment as 1.07 (95% CI 1.06-1.08). This research suggests that positive associations between coffee consumption and BC among male smokers but not never smokers and females. The inconsistent results between sexes and the absence of an association in never smokers indicate that the associations found among male smokers is unlikely to be causal and is possibly caused by residual confounding of smoking.

Impact of alcohol consumption on the risk of developing bladder cancer: a systematic review and meta-analysis

BACKGROUND

Epidemiologic studies that investigated alcohol consumption in relation to the risk of bladder cancer (BCa) have demonstrated inconsistent results. We conducted a systematic review and meta-analysis of the literature to investigate the association of alcohol including different types of alcoholic beverages consumption with the risk of BCa.

MATERIALS AND METHODS

A systematic search of Web of Science, Medline/PubMed and Cochrane library was performed in May 2018. Studies were considered eligible if they assessed the risk of BCa due to alcohol consumption (moderate or heavy dose) and different types of alcoholic beverages (moderate or heavy dose) in multivariable analysis in the general population (all genders, males or females) or compared with a control group of individuals without BCa.

STUDY DESIGN

observational cohorts or case-control.

RESULTS

Sixteen studies were included in this meta-analysis. Moderate and heavy alcohol consumption did not increase the risk of BCa in the entire population. Sub-group and sensitivity analyses revealed that heavy alcohol consumption increased significantly the risk of BCa in the Japanese population, RR 1.31 (95% CI 1.08-1.58, P < 0.01) in the multivariable analysis, and in males RR of 1.50 (95% CI 1.18-1.92, P < 0.01), with no significant statistical heterogeneity. Moreover, heavy consumption of spirits drinks increased the risk of BCa in males, RR 1.42 (95% CI 1.15-1.75, P < 0.01).

CONCLUSION

In this meta-analysis, moderate and heavy alcohol consumption did not increase the risk of bladder cancer significantly. However, heavy consumption of alcohol might increase the risk of BCa in males and in some specific populations.

Microbial Ecology of Fermented Vegetables and Non-Alcoholic Drinks and Current Knowledge on Their Impact on Human Health

Fermented foods are currently experiencing a re-discovery, largely driven by numerous health benefits claims. While fermented dairy, beer, and wine (and other alcoholic fermented beverages) have been the subject of intensive research, other plant-based fermented foods that are in some case widely consumed (kimchi/sauerkraut, pickles, kombucha) have received less scientific attention. In this chapter, the current knowledge on the microbiology and potential health benefits of such plant-based fermented foods are presented. Kimchi is the most studied, characterized by primarily acidic fermentation by lactic acid bacteria. Anti-obesity and anti-hypertension properties have been reported for kimchi and other pickled vegetables. Kombucha is the most popular non-alcoholic fermented drink. Kombucha's microbiology is remarkable as it involves all fermenters described in known fermented foods: lactic acid bacteria, acetic acid bacteria, fungi, and yeasts. While kombucha is often hyped as a "super-food," only antioxidant and antimicrobial properties toward foodborne pathogens are well established; and it is unknown if these properties incur beneficial impact, even in vitro or in animal models. The mode of action that has been studied and demonstrated the most is the probiotic one. However, it can be expected that fermentation metabolites may be prebiotic, or influence host health directly. To conclude, plant-based fermented foods and drinks are usually safe products; few negative reports can be found, but more research, especially human dietary intervention studies, are warranted to substantiate any health claim.

Tea Consumption and Risk of Bladder Cancer: A Dose-Response Meta-Analysis

Background and Objective: Controversial results of the association between tea (black tea, green tea, mate, and oolong tea) consumption and risk of bladder cancer were reported among epidemiological studies. Thus, we performed a meta-analysis of observational studies to investigate the association. Methods: We searched the PubMed and Embase for studies of tea consumption and bladder cancer that were published in any language up to March, 2016. Cohort or case-control studies were included in the meta-analysis. All statistical analyses were performed in Stata 12.0 software. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the relationship between tea consumption and risk of bladder cancer. Results: Totally, 25 case-control studies (15 643 cases and 30 795 controls) and seven prospective cohort studies (1807 cases and 443 076 participants) were included. The meta-analysis showed that tea consumption was not significantly associated with bladder cancer risk (OR = 0.96, 95% CI 0.86-1.06) (in a comparison of highest vs. lowest category). No non-linearity association was observed between tea consumption and bladder cancer risk (P = 0.51 for non-linearity). Specific analysis for black tea, green tea, and mate yielded similar results. The dose-response analysis showed the summary OR for an increment of 1 cup/day of tea consumption was 1.01 (95% CI 0.97-1.05). Conclusion: Results based on current meta-analysis indicated that no significant association was observed between tea consumption and risk of bladder cancer.

Quantified relations between exposure to tobacco smoking and bladder cancer risk: a meta-analysis of 89 observational studies

BACKGROUND

Smoking is a major risk factor for bladder cancer (BC). This meta-analysis updates previous reviews on smoking characteristics and BC risk, and provides a more quantitative estimation of the dose-response relationship between smoking characteristics and BC risk.

METHODS

In total, 89 studies comprising data from 57 145 BC cases were included and summary odds ratios (SORs) were calculated. Dose-response meta-analyses modelled relationships between smoking intensity, duration, pack-years and cessation and BC risk. Sources of heterogeneity were explored and sensitivity analyses were conducted to test the robustness of findings.

RESULTS

Current smokers (SOR = 3.14, 95% CI = 2.53-3.75) and former smokers(SOR = 1.83, 95% CI = 1.52-2.14) had an increased risk of BC compared with never smokers. Age at first exposure was negatively associated with BC risk. BC risk increased gradually by smoking duration and a risk plateau at smoking 15 cigarettes a day and 50 pack-years was observed. Smoking cessation is most beneficial from 20 years before diagnosis. The population-attributable risk of BC for smokers has decreased from 50% to 43% in men and from 35% to 26% in women from Europe since estimated in 2000. Results were homogeneous between sources of heterogeneity, except for lower risk estimates found in studies of Asian populations.

CONCLUSIONS

Active smokers are at an increased risk of BC. Dose-response meta-analyses showed a BC risk plateau for smoking intensity and indicate that even after long-term smoking cessation, an elevated risk of bladder cancer remains.

Possible relation between the NOS3 gene GLU298ASP polymorphism and bladder cancer in Turkey

Endothelial nitric oxide synthase (eNOS), encoded by the NOS3 gene, has been suggested to play an important role in uncontrolled cell growth in several cancer types. The objective of this study was to evaluate the role of the NOS3 Glu298Asp polymorphism in bladder cancer susceptibility in a Turkish population. We determined the genotypes of 66 bladder cancer cases and 88 healthy controls. Genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism analysis. A significant association for NOS3 Glu298Asp heterozygotes genotypes and T allely were found between healthy controls and bladder cancer, respectively (p<0.001: p=0.002). There were no significant associations between any genotypes and the stage, grade, and histological type of bladder cancer. Our study suggested an increased risk role of NOS3 GT genotype in bladder cancer susceptibility in our Turkish population.

A meta-analysis of tea consumption and the risk of bladder cancer

OBJECTIVE

Previous studies on the association between tea consumption and bladder cancer risk have only illustrated contradictory results. The role of tea in bladder carcinogenesis still remains conflicting. In order to illustrate the potential relationship between tea consumption and bladder cancer, a meta-analysis of case-control and cohort studies was conducted.

METHODS

Eligible studies were retrieved via both computerized searches and review of references. Stratified analyses on types of tea, gender, study design, ethnicity and smoking status were performed. Fixed- or random-effect models were used to summarize the estimates of OR with 95% CIs.

RESULTS

Seventeen studies were eligible for our analysis. No statistical significance was detected between tea consumption and bladder cancer risk when comparing the highest with the lowest intake of tea (OR = 0.825, 95% CI 0.652-1.043). In the subgroup of green tea, we observed it illustrated a protective effect on bladder cancer (OR = 0.814, 95% CI 0.678-0.976).

CONCLUSION

Our analysis indicated that green tea may have a protective effect on bladder cancer in Asian people. Further studies need to be conducted to better clarify the biological mechanisms.

Tea consumption and risk of bladder cancer: a meta-analysis

Background

Tea consumption has been reported to be associated with an decreased risk of several types of cancers. However, the results based on epidemiological studies on the association of tea consumption with bladder cancer were inconsistent. This meta-analysis was undertaken to evaluate the relationship between tea consumption and bladder cancer risk.

Methods

Eligible studies were retrieved via both computer searches and review of references. The summary relative risk (RR) with 95% confidence interval (CI) was calculated.

Results

Twenty three studies met the inclusion criteria of the meta-analysis. No association with bladder cancer was observed in either overall tea consumption group (OR =0.94, 95% CI 0.85-1.04) or subgroups stratified by sex, study design, geographical region or tea types.

Conclusions

Our findings did not support that tea consumption was related to the decreased risk of bladder cancer.

Evaluation of smoking genotoxicity in Turkish young adults

BACKGROUND:

For the past few decades, it has been widely known in developed countries that tobacco is dangerous, but it is still insufficiently realized how big these dangers really are.

AIMS:

To determine and evaluate micronuclei (MN) frequencies of young smokers and nonsmokers in three different tissues (peripheric blood lymphoctes, buccal mucosa, and exfoliative urothelial cells) at the same time.

MATERIALS AND METHODS:

MN assay was performed on buccal mucosa, urothelial cells, and peripheric blood lymphocyte samples obtained from 15 healthy male smokers (>5 pack-years) and 15 healthy male nonsmoker controls who had not been exposed to any known genotoxic agent.

STATISTICAL ANALYSIS USED:

The statistical differences between smoker and nonsmoker groups were calculated by using student t test. The differences between smoker-group tissues were compared by ANOVA.

RESULTS:

It was found that MN frequency (mean value ± standard deviation) in oral mucosa cells from smokers and controls were 1.20 ± 0.22% and 0.26 ± 0.10%; in urothelial exfoliative cells, 1.29 ± 0.28% and 0.12 ± 0.08%; in peripheric blood lymphocytes, 1.53 ± 0.23% and 0.38 ± 0.12%, respectively. The mean MN frequencies in buccal mucosa, urothelial exfoliative cells, and peripheric blood lymphocytes were significantly higher in smokers than in those of controls (P<0.05). All tissues were affected from smoking, but the most destructive effect was seen in urothelial cells of smokers (P<0.05).

CONCLUSIONS:

Our data showed that cigarette smoke is a DNA damage causitive agent on exfoliative buccal mucosa and urothelial cells and peripheric blood lymphocytes of young smokers, but it has most destructive effect on urothelial cells.

Coffee and its consumption: benefits and risks

Coffee is the leading worldwide beverage after water and its trade exceeds US $10 billion worldwide. Controversies regarding its benefits and risks still exist as reliable evidence is becoming available supporting its health promoting potential; however, some researchers have argued about the association of coffee consumption with cardiovascular complications and cancer insurgence. The health-promoting properties of coffee are often attributed to its rich phytochemistry, including caffeine, chlorogenic acid, caffeic acid, hydroxyhydroquinone (HHQ), etc. Many research investigations, epidemiological studies, and meta-analyses regarding coffee consumption revealed its inverse correlation with that of diabetes mellitus, various cancer lines, Parkinsonism, and Alzheimer's disease. Moreover, it ameliorates oxidative stress because of its ability to induce mRNA and protein expression, and mediates Nrf2-ARE pathway stimulation. Furthermore, caffeine and its metabolites help in proper cognitive functionality. Coffee lipid fraction containing cafestol and kahweol act as a safeguard against some malignant cells by modulating the detoxifying enzymes. On the other hand, their higher levels raise serum cholesterol, posing a possible threat to coronary health, for example, myocardial and cerebral infarction, insomnia, and cardiovascular complications. Caffeine also affects adenosine receptors and its withdrawal is accompanied with muscle fatigue and allied problems in those addicted to coffee. An array of evidence showed that pregnant women or those with postmenopausal problems should avoid excessive consumption of coffee because of its interference with oral contraceptives or postmenopausal hormones. This review article is an attempt to disseminate general information, health claims, and obviously the risk factors associated with coffee consumption to scientists, allied stakeholders, and certainly readers.

A meta-analysis of alcohol intake and risk of bladder cancer

OBJECTIVE

Epidemiologic studies have reported conflicting results relating alcohol intake to bladder cancer risk. A meta-analysis of cohort and case-control studies was conducted to pool the risk estimates of the association between alcohol intake and bladder cancer.

METHODS

Eligible studies were retrieved via both computer searches and review of references. We analyzed abstracted data with random effects models to obtain the summary risk estimates. Dose-response meta-analysis was performed for studies reporting categorical risk estimates for a series of exposure levels.

RESULTS

Nineteen studies met the inclusion criteria of the meta-analysis. No association with bladder cancer was observed in either overall alcohol intake group (OR = 1.00, 95% CI 0.89-1.10) or subgroups stratified by sex, study design, geographical region, or smoking status. However, in the analysis by specific beverages, both beer (OR = 0.86, 95% CI 0.76-0.96) and wine (OR = 0.85, 95% CI 0.71-1.00) consumption exhibited a negative dose-response relationship with bladder cancer.

CONCLUSION

The overall current literature on alcohol consumption and the risk of bladder cancer suggested no association, while the consumption of beer and wine was associated with reduced risk of bladder cancer. Further efforts should be made to confirm these findings and clarify the underlying biological mechanisms.

Coffee, green tea, and caffeine consumption and subsequent risk of bladder cancer in relation to smoking status: a prospective study in Japan

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.