Chronic Alcohol Consumption Associated With Higher Rectal Cancer Rates: Study

Lifetime heavy alcohol consumption significantly raises the risk of developing colorectal cancer, particularly rectal cancer, according to a new study published in CANCER. The findings emphasize that cumulative alcohol exposure over decades, not just current drinking habits, plays a major role in cancer risk.

Researchers analyzed health data from 88,092 adults who were cancer-free at enrollment in the National Cancer Institute’s Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Participants were followed for up to 20 years, during which 1,679 individuals were diagnosed with colorectal cancer.

Among current drinkers, those classified as heavy lifetime drinkers—averaging 14 or more drinks per week—had a 25% higher risk of colorectal cancer compared with people who averaged less than one drink per week over their lifetime.

The association was even more pronounced for rectal cancer, where heavy drinkers faced a 95% higher risk. Additionally, individuals who drank heavily across many years of adulthood had a 91% greater risk of colorectal cancer than consistent light drinkers.

Encouragingly, former drinkers did not show an increased colorectal cancer risk compared to light drinkers. They also had lower odds of developing colorectal adenomas, which are noncancerous growths that can later become malignant.

Although data on former drinkers were limited, the findings suggest that quitting alcohol may help lower long-term cancer risk.

Scientists believe alcohol may contribute to cancer development through toxic breakdown products like acetaldehyde or by disrupting gut microbiota and promoting inflammation. Further research is needed to clarify these mechanisms, but the results reinforce public health advice to limit alcohol intake to reduce cancer risk.

REFERENCE: Caitlin P. O’Connell, Sonja I. Berndt, Kenechukwu Chudy‐Onwugaje, Andrew Kunzmann, Wen‐Yi Huang, Kathryn Hughes Barry, Erikka Loftfield. Association of alcohol intake over the lifetime with colorectal adenoma and colorectal cancer risk in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Cancer, 2026; 132 (3) DOI: 10.1002/cncr.70201