The evidence regarding the effect of alcohol on bladder cancer is still inconclusive. But a new meta-analysis1 tries to shed light on the matter. It finds no effect of alcohol consumption on the risk of bladder cancer in the general population, but it does find an increased risk of heavy alcohol consumption on the risk in males, and an increased risk with drinking spirits. More research is needed.
What is already known? Previous meta-analyses find no increased risk of bladder cancer with moderate alcohol consumption, but the results of heavy alcohol consumption are inconsistent.2,3 One meta-analysis2 finds no association, but another finds an increased risk with heavy alcohol consumption in Japanese.3 All in all, the World Cancer Research Fund (WCRF) states that the evidence regarding the effect of alcohol on bladder cancer is limited and draws no conclusions.4
What does this study add? This meta-analysis only includes cohort studies and analyses whether the association between alcohol consumption and the risk of bladder cancer is different in men and women and different for the different types of alcoholic drinks. In total, nine studies are included.
Higher risk in males
At first glance, there is no association between alcohol consumption and bladder cancer. But when the authors look at the data of men and women separately, alcohol does increase the risk in men. More than two glasses a day gives a 23% increased risk of bladder cancer compared to non-drinking.
Increased risk with spirits
Looking at the different types of alcoholic beverages, data also show an increased risk with spirits. Every additional glass a day increases the risk with 9%.
Bladder cancer
Bladder cancer is the 10th most commonly diagnosed cancer worldwide with an estimated 549,000 new cases and 200,000 deaths each year. Men are more commonly affected by bladder cancer than women. Cigarette smoking is the biggest risk factor contributing to half of the risk of developing the disease.1
Strengths
- Only cohort studies included
- Separate analysis for type of drink
- Separate analysis for men and women
- Quality of studies assessed
Limitations
- Observational research – cannot prove causality
- Not accounted for ex-drinker
References
- Lao, Y., Li, X., He, L., Guan, X., Li, R., Wang, Y., … & Dong, Z. (2021). Association Between Alcohol Consumption and Risk of Bladder Cancer: A Dose-Response Meta-Analysis of Prospective Cohort Studies. Frontiers in oncology, 3381.
- Pelucchi, C., Galeone, C., Tramacere, I., Bagnardi, V., Negri, E., Islami, F., … & La Vecchia, C. (2011). Alcohol drinking and bladder cancer risk: a meta-analysis. Annals of oncology, 23(6), 1586-1593.
- Vartolomei, M. D., Iwata, T., Roth, B., Kimura, S., Mathieu, R., Ferro, M., … & Seitz, C. (2019). Impact of alcohol consumption on the risk of developing bladder cancer: a systematic review and meta-analysis. World journal of urology, 1-12.
- WCRF (2015) Diet, nutrition, physical activity and bladder cancer. Revised 2018.