Alcohol and Cancer Risk: What the Latest Science Tells Us

A strong and consistent body of evidence demonstrates a clear link between alcohol consumption and an increased risk of several types of cancer. This risk exists even at low levels of consumption and increases with the amount and frequency of alcohol intake. The underlying mechanisms are complex but include the production of toxic byproducts like acetaldehyde, oxidative stress, impaired nutrient absorption, and hormonal disruption. While some studies have suggested potential benefits of light drinking on cardiovascular health, the current consensus is that any potential benefits are outweighed by the risks, especially cancer risk. There is an increasing push for stronger health warning labels on alcoholic beverages to raise public awareness about these risks.

Key Themes and Findings --

 

Alcohol is a Carcinogen:

• Alcohol, specifically ethanol, is metabolized into acetaldehyde, a known carcinogen. This damages DNA and hinders cellular repair, promoting the growth of cancerous cells.
• "When the body breaks down ethanol, it becomes acetaldehyde, which Bevers says is a known carcinogen. 'This compound damages DNA and stops our cells from repairing the damage. This can allow cancerous cells to grow,' she explains." - MD Anderson Cancer Center
• "metabolizing (breaking down) ethanol in alcoholic drinks to acetaldehyde, which is a toxic chemical and a probable human carcinogen; acetaldehyde can damage both DNA...and proteins" - NCI Fact Sheet
• Alcohol can also generate reactive oxygen species which further damage DNA, proteins, and lipids.
• Alcohol can impair the body’s ability to absorb key nutrients that might be protective against cancer.

Types of Cancers Linked to Alcohol:

• Strongly Established Links: Alcohol consumption is consistently associated with increased risk of the following cancers:
• Oral cavity (mouth) and pharynx (throat)
• "Moderate drinkers have 1.8-fold higher risks of oral cavity...and pharynx (throat) cancers... and heavy drinkers have 5-fold higher risks of oral cavity and pharynx cancers..." - NCI Fact Sheet
• Larynx (voice box)
• "Moderate drinkers have... 1.4-fold higher risks of larynx (voice box) cancers... and heavy drinkers have... 2.6-fold higher risks of larynx cancers" - NCI Fact Sheet
• Esophagus (especially squamous cell carcinoma)
• "The risks, compared with no alcohol consumption, range from 1.3-fold higher for light drinking to nearly 5-fold higher for heavy drinking" - NCI Fact Sheet
• Liver
• "Heavy alcohol consumption is associated with approximately 2-fold increased risks of two types of liver cancer..." - NCI Fact Sheet
• Breast
• "light drinkers have a slightly increased (1.04-fold higher) risk of breast cancer, compared with nondrinkers. The risk increase is greater in moderate drinkers (1.23-fold higher) and heavy drinkers (1.6-fold higher)" - NCI Fact Sheet
• Colorectal
• "Moderate to heavy alcohol consumption is associated with 1.2- to 1.5-fold increased risks of cancers of the colon and rectum compared with no alcohol consumption." - NCI Fact Sheet
• Stomach - MD Anderson Cancer Center
• Emerging Links: There's growing evidence for links between alcohol and melanoma, and pancreatic and prostate cancers.

Dose-Response Relationship:

• The risk of cancer increases with increased alcohol consumption. Even light drinking has been shown to elevate risk compared to abstaining.
• "Pooled data from 118 individual studies indicates that light drinkers have a slightly increased (1.04-fold higher) risk of breast cancer, compared with nondrinkers. The risk increase is greater in moderate drinkers (1.23-fold higher) and heavy drinkers (1.6-fol