The Effect of Alcohol on the Digestive System: Does Alcohol Cause Cancer?

Alcohol is toxic to your digestive system. It can cause cancer of your mouth, throat, esophagus, liver, colon, and rectum. New studies show that even one drink a day can increase your risk for digestive cancer.

saying no to alcohol, long term effects of alcohol

According to a WHO study, even one drink of alcohol per day may raise your risk for digestive cancer. It may be best to avoid alcohol all together.

© itakdalee | Getty Images

Alcohol is the most commonly used drug in the world. When you drink alcohol, it is absorbed in your digestive system and moves into your blood. In your blood, alcohol travels to your liver, where 90 percent of alcohol is broken down and eliminated. The rest comes out in your sweat, urine, and breath.  Along its course through your digestive system, alcohol can cause cancer of your mouth, throat, esophagus, liver, colon, and rectum.

How Does Alcohol Affect your Digestive System?

A substance that can cause cancer is called a carcinogen. For example, the many carcinogens found in tobacco smoke. A molecule of alcohol is also a carcinogen. Alcohol can cause damage to the cells of your digestive system because alcohol interferes with the ability of cell DNA to repair cell damage. Damaged cells are more likely to become cancer cells.

If you smoke and drink alcohol, alcohol acts as a solvent and allows more of the carcinogens in tobacco smoke to enter the cells of your mouth and throat. That is why these cancers are highest in people who both smoke and drink alcohol.

Alcohol has its worst effects on your liver. When your liver breaks down alcohol, a carcinogen called acetaldehyde is formed. This carcinogen directly damages cells of the liver. Liver damage leads to liver scarring called cirrhosis. About 30 percent of liver cancers occur in people with cirrhosis.

How Risky Is Alcohol for Cancer of Your Digestive System?

According to the Centers for Disease Control and Prevention (CDC), and the 2025 Dietary Guidelines for Americans, if you chose to drink alcohol, you should drink in moderation. Moderate drinking is no more than two drinks in a day for men or one drink in a day for women. One drink could be 12 ounces of beer, 5 ounces of wine, or one shot of vodka, gin, whisky, or rum.

However, according to the WHO study, even one drink of alcohol per day may raise your risk for digestive cancer significantly. The findings of their study are published in the medical journal Lancet. These were some of the key findings on alcohol and digestive cancer:

  • Cancers were highest in men, close to 80 percent were in men.
  • The most common cancers were of the esophagus and liver.
  • One in seven cancers were linked to one or two drinks per day.
  • Having one or two drinks per day was estimated to cause more than 100,000 cancers in 2020.

A 2021 study that reviewed the effects of alcohol on digestive health was published in the journal Nutrients. This study found that alcohol caused 2.8 million deaths in 2016, and was the leading cause of death in people under age 50 worldwide.

A growing amount of evidence is showing that no amount of alcohol is safe. For women, alcohol is strongly linked to breast cancer. Alcohol use is also a cause of alcohol addiction, malnutrition, heart disease, and accidental deaths. In fact, the CDC is now saying drinking in moderation should not be considered safe drinking. CDC also says that older studies suggesting that moderate drinking is good for heart health have not been supported by more recent studies.

What Are the Long Term Effects of Alcohol?

Drinking one to two drinks of alcohol in a day may increase your risk of death, mainly from heart disease or cancer. The researchers from the WHO say that it is time for public policy to catch up to recent research. They suggest ways to lower alcohol use like banning advertising, increasing alcohol taxes, and putting warning labels on alcohol. In other words, they suggest starting to treat alcohol more like cigarettes. You can still choose to drink but you need to know the risk.

As a service to our readers, University Health News offers a vast archive of free digital content. Please note the date published or last update on all articles. No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.

Tags: , , , , , , , , , , , , , , , , ,

Chris Iliades, MD

Dr. Chris Iliades is board-certified in Ear, Nose and Throat and Head and Neck Surgery from the American Board of Otolaryngology and Head and Neck Surgery. He holds a medical … Read More

View all posts by Chris Iliades, MD

Enter Your Login Credentials
This setting should only be used on your home or work computer.