Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
, 16, 66
eCollection

Association Between Coffee Consumption and Risk of Bladder Cancer in a Meta-Analysis of 16 Prospective Studies

Affiliations

Association Between Coffee Consumption and Risk of Bladder Cancer in a Meta-Analysis of 16 Prospective Studies

Zhi-Wei Dai et al. Nutr Metab (Lond).

Abstract

Background: Current evidence remains equivocal as to whether and how consumption of coffee may be associated with risk of bladder cancer, and potential influence of confounding by smoking on this association is yet to be elucidated. We conducted an updated meta-analysis of prospective studies to address these issues.

Methods: Relevant studies were identified by searching PubMed and EMBASE databases from inception to April 2019. A random-effects model was used to estimate summary relative risk (RR) with corresponding 95% confidence interval (CI) of bladder cancer associated with coffee consumption.

Results: The final analysis included 16 prospective studies comprising 2,122,816 participants and 11,848 bladder cancer cases. Overall, coffee consumption was not associated with risk of bladder cancer (RR high-vs-low = 1.07, 95% CI: 0.96-1.20). The lack of association persisted in the strata defined by sex or participants' smoking status. Meta-regression analyses identified the number cases (P difference = 0.06) and the degree of adjustment for smoking (P difference = 0.04) as potential sources of heterogeneity. There was an increased risk of bladder cancer related to higher coffee consumption among studies with fewer cases (RR high-vs-low = 1.38, 95% CI: 1.05-1.81) and among those with poorer adjustment for smoking (RR high-vs-low = 1.48, 95% CI: 1.14-1.93). Results were similar in the dose-response analyses (RR 1 cup/d = 1.01, 95% CI: 0.98-1.03).

Conclusion: Best evidence available to date does not support an independent association between coffee consumption and bladder cancer risk. Some direct associations observed in individual studies may be a result of residual confounding by smoking.

Supplementary information: Supplementary information accompanies this paper at 10.1186/s12986-019-0390-3.

Keywords: Bladder cancer; Coffee; Cohort studies; Meta-analysis.

Conflict of interest statement

Competing interestsThe authors declare that they have no competing interests.

Figures

Fig. 1
Fig. 1
Flow chart of study selection
Fig. 2
Fig. 2
Forest plots for the meta-analysis of coffee consumption and risk of bladder cancer. a highest vs. lowest analysis; b dose-response analysis of 1 cup/d increment. M, men; W, women

Similar articles

See all similar articles

References

    1. Poole R, Kennedy OJ, Roderick P, Fallowfield JA, Hayes PC, Parkes J. Coffee consumption and health: umbrella review of meta-analyses of multiple health outcomes. BMJ. 2017;359:j5024. doi: 10.1136/bmj.j5024. - DOI - PMC - PubMed
    1. Alicandro G, Tavani A, La Vecchia C. Coffee and cancer risk: a summary overview. Eur J Cancer Prev. 2017;26(5):424–432. doi: 10.1097/CEJ.0000000000000341. - DOI - PubMed
    1. Cancer IAfRo . IARC Monograph on the Evaluation of Carcinogenic Risk of Chemicals to Humans Suppl. 1991. Coffee, tea, mate, Methylxanthines, and Methyglyoxal; p. 51. - PubMed
    1. Loomis D, Guyton KZ, Grosse Y, Lauby-Secretan B, El Ghissassi F, Bouvard V, et al. Carcinogenicity of drinking coffee, mate, and very hot beverages. Lancet Oncol. 2016;17(7):877–878. doi: 10.1016/S1470-2045(16)30239-X. - DOI - PubMed
    1. Gapstur SM, Anderson RL, Campbell PT, Jacobs EJ, Hartman TJ, Hildebrand JS, et al. Associations of coffee drinking and Cancer mortality in the Cancer prevention study-II. Cancer Epidemiol Biomark Prev. 2017;26(10):1477–1486. doi: 10.1158/1055-9965.EPI-17-0353. - DOI - PubMed

LinkOut - more resources

Feedback