Question & Answer

The Evidence

• We looked for studies to find out whether or not drinking alcohol causes cancer.
• We found several relevant systematic reviews carried out in the last five years. Some were high quality, and some were medium-to-low quality reviews. However, it is important to note that sometimes even a high quality review can have low quality studies in it.
• One systematic review explored the link between light alcohol drinking and the risk of cancer. The systematic review looked at a type of study that follows people over time called a cohort study. These studies reported that very light or light alcohol drinking can cause breast cancer in women and cancer of the colon/large intestine in men.
• We identified three systematic reviews on cancer of the colon/ large intestine.
  • The first systematic review looked at cohort studies and case-control studies. The studies reported that drinking alcohol is an important risk factor for developing cancer of the colon/ large intestine.
  • The second systematic review looked at cohort studies. These studies found that drinking alcohol is linked to a higher risk of dying from colon or large intestine cancer.
  • The third systematic review looked at three different types of studies, including ones that tracked groups over time (cohort studies), studies comparing people with and without a condition (case-control studies), and studies that looked at one point in time (cross-sectional studies). However, cross-sectional studies can’t show that one thing causes another because they don’t compare two similar groups — one that drinks alcohol and one that doesn’t. Despite this limitation, this review also found that alcohol has a strong link to colon or large intestine cancer.
• Another systematic review looked at case-control studies in African population.  The studies reported a relationship between drinking alcohol and cancer of the throat.
• We identified two systematic reviews on liver cancer.
  • The first systematic review looked at cohort studies and case-control studies. The studies reported that drinking alcohol regularly is linked to liver cancer.
  • The second systematic review looked at case-control studies conducted in China. The studies reported that drinking alcohol increased the risks of liver, throat and stomach cancers.
• There was one systematic review on breast cancer. This review looked at cohort studies, case-control studies, and cross-sectional studies. The studies reported that drinking alcohol has no link to developing breast cancer. The review authors felt that underreporting of alcohol consumption or absence of alcohol in some countries could help explain the absence of the link between alcohol consumption and breast cancer risk.
• There was one systematic review on urinary bladder cancer. The studies reported that drinking alcohol increases the risk of men getting urinary bladder.
• One systematic review found no link between wine drinking and the risk of developing any type of cancer. However, this review focused only on wine drinking, not other types of alcohol.

Guidelines and recommendations

• We searched several national and international organisations, including WHO, CDC, and HSE, for related guidelines and recommendations.
• The World Health Organization (WHO) states that even light or moderate alcohol consumption can lead to the development of cancer.
• The Centers for Disease Control and Prevention (CDC) has indicated that consuming alcohol increases the risk of various types of cancer.
• The Health Service Executive (HSE) states that drinking alcohol is linked to several kinds of cancer.