Alcohol is now recognized as a major carcinogen, responsible for increasing the risk of at least seven types of cancer: cancers of the lip and oral cavity, pharynx, larynx, breast, colon, rectum, liver, and esophagus. The relationship is dose-dependent—the more alcohol consumed, the higher the cancer risk. Globally, alcohol contributes to about 4.1% of all new cancer diagnoses, translating to over 300,000 cases each year. In the United States, it is the third leading preventable cause of cancer after smoking and obesity, accounting for 5.4% of new cancers and 4.1% of cancer deaths in adults over 30 years old. In Europe, the burden is even greater, with alcohol causing approximately 10% of cancers in men and 3% in women.
What is the link between alcohol and cancer?
Those who drink at most one drink per day (light drinkers) versus those who drink at least four drinks per day (heavy drinkers) have markedly different risks of developing each of these cancers. For oral and pharyngeal cancers that occur in the back of the mouth and upper throat, heavy drinkers are 4–5 times more likely to develop these cancers than light drinkers. Light drinkers’ risk is just slightly above average, with about a 10% increase, whereas heavy drinkers may have up to a 660% increased risk compared with non-drinkers.
For cancers of the esophagus (the tube that connects the mouth to the stomach) and stomach, heavy drinkers have 2.5–5 times the risk of light drinkers. Heavy drinkers also have about a 150% increased risk of colon, liver, and female breast cancers. There may even be elevated risks of melanoma, an aggressive skin cancer, and gallbladder cancers.
Lip, Oral Cavity, Pharynx, and Larynx Cancers
Lip and Oral Cavity: 15,000 new cases from alcohol use every year.
Pharynx (top of the throat): 8,700 new cases from alcohol use every year.
Larynx (top of the airway or ‘voice box’): 4,100 new cases from alcohol use every year.
Esophagus (and upper stomach): 60000 new cases from alcohol use every year.
Drinking alcohol can raise the risk of cancers in the mouth (oral and lip cancers), top of the throat (pharynx), voice box (larynx), and even in the tube that connects the mouth to the stomach (esophagus) and top of the stomach because of the way the body—and even the bacteria in the mouth—process alcohol. When alcohol is broken down, it forms a substance called acetaldehyde, which is toxic and can damage DNA, making it easier for cells to become cancerous. Over time, heavy drinking also changes how cells in the mouth grow and behave, making cancers more aggressive and harder to treat. Alcohol is a solvent, or liquid that dissolves components of solids, allowing harmful chemicals from things like tobacco to get into the mouth’s lining more easily. On top of that, regular alcohol use causes ongoing irritation and inflammation of the mouth, and changes in the balance of bacteria in the mouth, all of which further increase the chance of cancer developing.
Liver cancer
26,800 new cases from alcohol use every year.
Similar to how alcohol can cause cancers of the mouth to stomach, alcohol causes cancers of the liver, primarily hepatocellular carcinoma. Alcohol itself is a poison, and metabolized in the liver itself into acetaldehyde, a direct toxin to the DNA in the liver. There is also a dose-dependent relationship between alcohol consumption, starting at just one drink or (10 grams per day) of alcohol that increases the risk of hepatocellular carcinoma. Alcohol has synergistic effects in the liver as well to create cancer, but with a broader range than just with tobacco. Viral infections, like hepatitis B and C as well as obesity and diabetes confer increased risk for liver cancer with alcohol consumption, primarily through chronic inflammation of the organ.
Colon & Rectum Cancers
Colon: 7,400 new cases from alcohol use every year.
Rectum: 6,000 new cases from alcohol use every year.
The colon and rectum are the final parts of digestion, where water is absorbed and stool is stored. Again, similar to the above cancers, alcohol increases colon cancer risk by its conversion to the toxic metabolite, acetaldehyde and the direct effects on the tissues in the colon to damage DNA, beginning the conversion of a normal cell to a cancerous or malignant cell. More alcohol consumption and more years of exposure increase cancer risk in a dose- and time-dependent manner, especially in men, where risk may be up to 2.5 times higher. Unfortunately, quitting drinking does not remove or decrease cancer risk from previous alcohol exposure, unlike quitting smoking does. Additional factors that amplify alcohol’s effects include folate deficiency, low-fiber diets (common in heavy drinkers due to poor nutrition), and tobacco use.
Female Breast Cancer
4,325 new cases from alcohol use every year.
Acetaldehyde also plays a key role in breast cancer development. Risk rises with rising alcohol intake, beginning as early as three drinks per week, which increases breast cancer risk by at least 4% compared with non-drinkers. Drinking after menopause appears to raise risk more than drinking before menopause. Unlike other alcohol-related cancers, tobacco does not seem to compound risk for breast cancer, although folate deficiency does.
Key Points
Alcohol is a proven carcinogen and third leading cause of cancers, second only to smoking and obesity in the United States. Alcohol consumption is linked to cancers of the mouth, throat, voice box, esophagus, liver, colon, rectum, and breast. The risk rises with both the amount consumed and the number of years of drinking, with heavy use multiplying cancer risk several times over. Alcohol damages DNA through its toxic breakdown product, acetaldehyde, while also amplifying the effects of other risk factors like poor nutrition, smoking, and chronic inflammation. Unlike smoking, where quitting lowers risk over time, past alcohol exposure leaves a lasting imprint on cancer risk. Understanding alcohol’s role as a cancer-causing agent is critical, both for personal health decisions and for broader public health efforts to reduce preventable cancers worldwide.
Sources
- https://jamanetwork.com/journals/jama/article-abstract/2837352
- https://www.sciencedirect.com/science/article/pii/S187778211630176X?via%3Dihub
- https://pmc.ncbi.nlm.nih.gov/articles/PMC4453639/
- https://www.nejm.org/doi/full/10.1056/NEJMsr2306723
- https://pmc.ncbi.nlm.nih.gov/articles/PMC5574999/
- https://pubmed.ncbi.nlm.nih.gov/30658729/
- https://pubmed.ncbi.nlm.nih.gov/39689032/
- https://pubmed.ncbi.nlm.nih.gov/27943267/
- https://pubmed.ncbi.nlm.nih.gov/29385712/
- https://pmc.ncbi.nlm.nih.gov/articles/PMC11629438/
- https://jamanetwork.com/journals/jama/fullarticle/1104580