A Lifetime of Drinking Alcohol Increases Colorectal Cancer Risk

While many consumers are cutting back on their drinking habits and adopting a sober lifestyle, the damage may already be done for those with lifelong drinking habits. In fact, a recent study suggests that long-term alcohol use may lead to higher risks of colorectal cancer.

Lifelong Alcohol Use and Colorectal Cancer

Affecting the colon or rectum, colorectal cancer is the third most common cancer worldwide and the second-leading cause of cancer-related deaths globally.

Alongside a family history of colorectal cancer, factors that can increase colorectal cancer include obesity, long-term tobacco use, a diet high in red meats and processed foods, and excessive alcohol use. That said, data on the link between lifetime alcohol drinking and colorectal cancer risk is limited.

As such, this article will explore how researchers sought to evaluate the association between average lifetime alcohol drinking, as well as changes in alcohol consumption over adulthood, with incident colorectal adenoma (precancerous lesions that can develop into cancer) and cancer. Because colorectal cancer has a 90% or higher 5-year survival rate when detected early, screening for and detecting colorectal adenomas is critical to survival.

For the study, the scientists analyzed existing data on 88 092 U.S. adults enrolled in the National Cancer Institute (NCI) Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. The participants had reported their alcohol use beginning in early adulthood and were followed for nearly a decade to track cancer outcomes. At baseline, the participants did not have cancer, yet over 20 years of follow-up, 1679 colorectal cancer cases did occur.

Lifetime Alcohol Consumption Causes Colorectal Cancer

Per the findings, published in Cancer Research, higher lifetime consumption of alcohol was associated with a higher risk for colorectal cancer.

For lifetime average heavy drinkers (≥14 drinks per week), they had a 25% higher risk of developing colorectal cancer and a 95% higher risk of developing rectal cancer when compared to lifetime average light drinkers (<1 drink per week).

What’s more, the researchers found zero evidence of increased colorectal cancer risk among former drinkers. Former drinkers also had a lower likelihood of developing noncancerous colorectal tumors, or adenomas, than current light drinkers. This then suggests that quitting alcohol may lower individuals’ risks and protect their health. That said, these data were limited.

The association between alcohol consumption and increased risks observed in this and other studies might be explained by carcinogens produced from alcohol metabolism or alcohol’s effects on gut microbes. Additional studies are needed to test whether these mechanisms are involved.

“Our study is one of the first to explore how drinking alcohol over the life course relates to both colorectal adenoma and colorectal cancer risk. While the data on former drinkers were sparse, we were encouraged to see that their risk may return to that of the light drinkers,” – Erikka Loftfield, PhD, MPH, of the NCI, co–senior author

Screening

Adopting a healthy lifestyle that includes regular exercise, stress management, and a plant-based diet is a great way to curb your cancer risk, but the importance of regular screening should not be understated.

Recommended for all adults aged 45 and upwards,  those who may face a higher risk may need to be screened at an early age or more often, especially if they experience symptoms like bleeding or persistent changes in their bowel movements.

Want to know more?

The reality is that if you drink alcohol, you may be at risk of getting cancer. Here are the7 types of cancer directly linked to drinking alcohol.

References

O’Connell, C.P., Berndt, S.I., Chudy-Onwugaje, K., Kunzmann, A.T., et al. (2025). Abstract 1197: Association of increasing alcohol intake over the lifetime with colorectal adenoma and colorectal cancer risk in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Cancer Research, 85(8_Supplement_1), pp.1197–1197. doi:https://doi.org/10.1158/1538-7445.am2025-1197.

World Health Organization (2023). Colorectal Cancer. [online] World Health Organization. Available at: https://www.who.int/news-room/fact-sheets/detail/colorectal-cancer.