Many studies have found a connection between alcohol consumption and colorectal cancer. Most of these studies suggest that the link becomes stronger the more alcohol you consume.

Consuming alcohol in moderate to large quantities can have many negative health effects, including increasing your chance of developing colorectal cancer. Colorectal cancer develops in your large intestines or your rectum.

Read on to learn more about the connection between drinking alcohol and the risk of developing colorectal cancer.

Alcohol consumption is a major risk factor for the development of colorectal cancer. The connection has been well-established, and the risk seems to be highest for heavy drinkers.

Alcohol found in alcoholic drinks is called ethanol. The breakdown of ethanol by your gastrointestinal tract can generate toxic substances like acetaldehyde. These substances can damage the DNA of cells in your colon and rectum. Damage to their DNA can cause the cells to replicate uncontrollably and form a tumor.

Ethanol may also cause changes to your gut’s microbiome that cause bowel inflammation and possibly activate enzymes that make you more prone to developing cancer.

What are 95% confidence intervals?

When reporting cancer risk, researchers often give 95% confidence intervals (CI) to help account for statistical error.

For example, if researchers report the chances of developing cancer are 50% higher in a certain population with 95% CI from 40–60%, there’s a 95% chance that this group of people have between a 40–60% increased cancer risk.

Was this helpful?

Alcohol use disorder and colorectal cancer

In a large study from Taiwan, researchers analyzed the association between alcohol use disorder and colorectal cancer risk among 49,095 people who developed colorectal cancer. Alcohol use disorder is defined as:

  • habitual alcohol consumption
  • loss of control over alcohol intake
  • negative emotional state when not using alcohol

The researchers found that people with alcohol use disorder had a 63.1% higher chance of developing colorectal cancer (95% CI between 56.5% and 69.9%) than people without alcohol use disorder.

The risk became higher with a longer duration of alcohol use disorder, reaching 167% (95% confidence intervals of 151.1–198.9%) after 11 years.

Heavy drinking and colorectal cancer

In a 2019 review of 16 studies, researchers collected information from 14,276 people with colorectal cancer and 15,802 people without colorectal cancer. They found supporting evidence that the link between alcohol consumption and colorectal cancer follows a J-curve, with higher amounts of alcohol causing rapidly higher rates of colorectal cancer.

They found:

  • drinking up to two drinks per day was associated with an 8% lower risk (95% confidence intervals of 2–12%) of developing colorectal cancer compared with not drinking or occasional drinking
  • drinking two to three drinks per day was not associated with a higher risk of colorectal cancer (11% higher risk with 99% CI ranging from 1% lower to 24% higher)
  • drinking more than three drinks per day was associated with a 25% higher risk of colorectal cancer (95% CI 11–40%)

Drinking alcohol in an attempt to lower the risk of getting cancer is not recommended, as the negative effects of alcohol outweigh the potential benefits.

Alcohol consumption and early colorectal cancer risk

In a 2023 study, researchers investigated the link between daily alcohol consumption and the risk of early onset colorectal cancer using national health insurance data from more than 5.6 million people in South Korea between the ages of 20 and 49 years.

The researchers found that 8,314 people developed colorectal cancer during the 10-year study period. Light drinkers had a 9% (95% CI 2–16%) higher risk of developing colorectal cancer than non-drinkers. Heavy drinkers had a 20% higher chance (95% CI 11–29%).

Alcohol consumption and early colorectal cancer risk by ethnicity

In a 2019 study, researchers analyzed data from nearly 200,000 people in Hawaii or California in the following racial or ethnic groups:

  • Black
  • Native Hawaiian
  • Japanese-American
  • Latino
  • white

The researchers found an increased risk of colorectal cancer with alcohol consumption among all of these groups other than Black. They also found alcohol consumption was associated with a higher risk among people with:

Alcohol and other types of cancer

According to the National Cancer Institute, alcohol consumption increases the risk of other cancers.

CancerRisk
head and neck cancer1.8 times increased risk for moderate drinkers
esophageal cancer1.3 times increased risk for light drinkers and 5 times increased risk for heavy drinkers
liver cancer 2 times increased risk for heavy alcohol consumption
breast cancer1.04 times increased risk for light drinking, 1.23 times increased risk for moderate drinking, and 1.6 times risk for heavy drinking

Researchers are investigating the compound resveratrol found in grapes for possible health effects, such as cancer prevention. According to the National Cancer Institute, no association has been found between moderate consumption of red wine and the risk of prostate or colorectal cancer.

In a 2023 review of studies, researchers found no association between wine consumption and the risk of developing any type of cancer.

Approximately 10% of people who develop colorectal cancer have associated genes passed through families.

Consuming alcohol has been linked to a higher risk of developing colorectal among people with a family history of colorectal cancer compared to people without a family history.

Most studies suggest that cancer risk declines once you stop drinking alcohol. Although, most of these studies have examined the risk of head and neck or esophageal cancers.

It may take years for the risk of cancer to fall to the same risk for people who never drank heavily.

According to the Centers for Disease Control and Prevention (CDC), the most effective way to reduce your risk of colorectal cancer is to get screened regularly beginning at age 45. Screenings can help identify small growths called polyps before they turn into cancer.

Other lifestyle habits that may reduce your risk of colorectal cancer include:

Learn more about preventing colon cancer.

Alcohol consumption is a well-established risk factor for the development of colorectal cancer. The risk seems to be highest if you drink heavily for many years.

Reducing your alcohol consumption may help lower your risk of developing colorectal cancer. However, it may take many years for your risk to drop to that of somebody who never drank heavily.