The intoxicating truth: Alcohol’s connection to cancer

It’s Friday night! The possibilities are endless, the drinks are flowing, and as the burn of the last shot fades away, so do the anxieties of its adverse effects in the morning. However, consuming alcohol is now being linked to much larger consequences than just a hangover. 

Former United States Surgeon General Dr. Vivek Murthy released a new advisory on alcohol and its direct link to cancer on January 3, 2025. The advisory indicates that alcohol use is the third leading preventable cause of cancer in the United States, following tobacco use and obesity. Evidence of a direct relationship between alcohol use and an increased risk for cancer has been identified for seven kinds of cancer, including mouth, larynx, pharynx, liver, esophagus, colorectum, and breast (in women). The risk of cancer is greater as more alcohol is consumed, however, less than half of adults in the U.S. are aware of the risk alcohol poses.

Alcohol was first classified as a carcinogen in 1988 by the International Agency for Research on Cancer. Studies showing evidence of this connection have continued to be published since, but still, 72% of adults in the U.S. reported consuming at least one drink or more each week in 2019-2020. In 2020, there were 741,300 reported cancer cases related to alcohol consumption worldwide. Annually, there are nearly 20,000 deaths related to cancers that were linked to alcohol use. To put that into perspective, 13,500 traffic fatalities involve alcohol annually. 

“The advisory indicates that alcohol use is the third leading preventable cause of cancer in the United States, following tobacco use and obesity.”

When alcohol is consumed, it is broken down by an enzyme called alcohol dehydrogenase, which metabolizes the alcohol into acetaldehyde, a known carcinogen that has the ability to damage DNA. Acetaldehyde can cause cells to grow uncontrollably, leading to cancer. Fortunately, acetaldehyde is only present in the body briefly before it is further broken down by another enzyme called aldehyde dehydrogenase, which turns the acetaldehyde into acetate, a much less harmful byproduct. Alcohol’s metabolism has other dangerous side effects and pathways to cancer, including the production of unstable reactive oxygen species which can further damage cells and cause cancer, as well as the disruption of hormones, like estrogen playing a direct role in the development of breast cancer. 

Alcohol causing an increased risk of cancer is not as well known as other preventable causes, including radiation and tobacco use. 91% of Americans recognized radiation as increasing the risk of cancer, and 89% recognized tobacco as increasing the risk. In comparison, only 45% of Americans recognized alcohol’s connection to cancer. The difference in this recognition between tobacco products and alcohol can also be seen on the required warning labels on either product. Cigarette packaging requires the warning to take up at least 50% of the front and back of the packaging and requires various warnings, which include the risk of cancer. In contrast, on alcohol, there are two required warnings stating that the consumption of alcohol is dangerous during pregnancy, and not to operate a car or machinery when drinking. 

The Surgeon General’s advisory calls for the warning label on alcoholic beverages to be updated to include the risk of alcohol-related cancers to stress the danger that alcohol consumption has always had. An increased awareness of this risk may cause Friday night’s plans to change, but to avoid cancer and a nasty hangover, this sobering change could be quite beneficial.