A major study from the United States has revealed that long-term heavy alcohol consumption significantly increases the risk of developing colorectal cancer (CRC). The research, published in the journal Cancer, utilized data from the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial to assess how cumulative alcohol intake over a lifetime correlates with the onset of colorectal adenomas, which are precancerous polyps, and invasive cancer.
The findings indicate that individuals with a history of high alcohol consumption face a notably higher risk of CRC. Specifically, current drinkers who averaged 14 or more drinks per week were found to have a 25% greater risk of developing CRC compared to those consuming less than one drink per week. The study also demonstrated that stopping alcohol consumption may reduce the chances of developing early-stage nonadvanced adenomas.
Link Between Alcohol and Colorectal Cancer
Colorectal cancer remains a leading cause of cancer-related mortality, ranking as the third most common cancer in the United States. Although overall incidence rates have declined, diagnoses among adults under the age of 55 are on the rise. This trend has prompted health officials to prioritize the identification and management of modifiable risk factors, with alcohol consumption recognized as a significant contributor. The International Agency for Research on Cancer (IARC) has classified alcoholic beverages as carcinogenic to humans, specifically associating them with colorectal cancer risks.
Previous studies often focused on short-term alcohol consumption, providing only a snapshot of participants’ drinking habits. This approach overlooks the protracted nature of cancer development, which can take decades. The current study sought to fill this gap by reconstructing participants’ alcohol intake histories from age 18 onward, emphasizing the importance of understanding cumulative exposure.
Study Methodology and Key Findings
The research analyzed data from a cohort of 88,092 participants who were followed for clinically diagnosed cancer. The study also included an incident adenoma cohort of 12,327 individuals who underwent flexible sigmoidoscopy screening. Participants provided detailed dietary histories regarding their beer, wine, and liquor consumption across four age groups: 18–24, 25–39, 40–54, and 55 years and older.
Using this data, researchers categorized participants based on their lifetime average alcohol consumption. Those consuming less than one drink per week served as the reference group. The analysis revealed that consistent heavy drinkers faced a 91% higher risk of CRC compared to consistent light drinkers. Notably, heavy drinking was particularly linked to rectal cancer, with heavy drinkers nearly doubling their risk when compared to light drinkers.
The study also found a nonlinear association for moderate drinkers. Participants averaging 7 to <14 drinks per week exhibited a lower risk of CRC compared to those consuming less than one drink per week, especially for distal colon cancer. However, researchers cautioned that this finding may not suggest a protective effect of alcohol consumption but could stem from various confounding factors.
Former drinkers showed a marked decrease in the likelihood of developing nonadvanced adenomas, underscoring the potential health benefits of reducing alcohol consumption, even later in life.
In conclusion, the study highlights the crucial link between cumulative alcohol exposure and colorectal cancer risk. The data suggest that heavy drinking is a significant risk factor, particularly for rectal cancer, while cessation may lower the odds of developing precancerous lesions. Despite the observational nature of the study and its limitations, including reliance on self-reported alcohol intake, the findings call for an emphasis on lifestyle changes to mitigate long-term cancer risks. Public health strategies may need to focus not just on immediate health outcomes but also on the broader implications of alcohol consumption on cancer risk over a lifetime.
The research was led by O’Connell CP and is set for publication in 2026.
