Numerous studies have established the relationship between alcohol consumption and colorectal cancer risk. Research shows a positive correlation, with heavy drinkers facing the highest risk.
During digestion, ethanol in alcohol is broken down into toxic substances like acetaldehyde in the gut. These substances can damage the DNA of colon and rectal cells. Damaged DNA can cause uncontrolled cell replication and formation of tumors. Ethanol may also alter gut microbiome, leading to inflammation in the intestines and activation of enzymes that increase cancer risk.
One study found that individuals with alcohol use disorder had a 63.1% higher risk of colorectal cancer than those without, and risk increased with longer duration of heavy drinking. Another study demonstrated a direct correlation between alcohol intake and colorectal cancer incidence - drinking over three drinks per day increased risk by 25%. It's not recommended to use alcohol to lower cancer risk as its negative impacts outweigh potential benefits.
Previous research also linked drinking to higher risks of other cancers.
Oropharyngeal cancer (cancer of the mouth and throat):
Moderate drinking increased risk by 1.8 times compared to non-drinkers.
Esophageal cancer (cancer of the gullet or food pipe):
Light drinking increased risk by 1.3 times.
Heavy drinking increased risk substantially more, by 5 times.
Liver cancer:
Heavy drinking doubled the risk compared to non-drinkers.
Breast cancer:
Light drinking led to a small increased risk of 1.04 times.
Moderate drinking saw a slightly higher rise in risk of 1.23 times.
Heavy drinking corresponded to the highest breast cancer risk increase of 1.6 times.
Most studies show risk decreases after stopping alcohol, but may take years to reach levels of lifetime non-heavy drinkers. The most effective way to lower colorectal cancer risk according to CDC is regular screening from age 45. Other lifestyle changes like increased physical activity, maintaining a healthy weight, limiting alcohol intake (if drinking), not smoking (if applicable), and dietary modifications can also help lower colorectal cancer risk.
