Drinking an average of fourteen alcoholic drinks a week doubles the colorectal cancer risk according to a large U.S. study, as cases rise among people younger than fifty and researchers point to alcohol as a preventable risk factor.
Researchers analyzed data from more than eighty-eight thousand adults and found that people who consumed about two drinks a day faced sharply higher risks of both colon and rectal cancer, according to findings published in the journal Cancer.
The study drew from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, a long-running federal research project tracking health outcomes in adults across the United States. Participants who consistently drank heavily had roughly double the risk of developing colorectal cancer compared with those who drank lightly.
Specifically, people who averaged fourteen drinks per week had a twenty-five percent higher risk of rectal cancer and a ninety-five percent higher risk of colon cancer, researchers reported.
“The longer someone drinks, the longer their colon and rectum are exposed to damage and impaired repair, both major mechanisms of cancer,” said Dr. Lynn O’Connor, section chief of colon and rectal surgery at Mercy Medical Center and St. Joseph Hospital, in an interview with ABC News.
Younger Adults Drive Worrying Rise in Colorectal Cancer Risk Cases
The findings come as colorectal cancer rates climb steadily among younger adults, a trend that has alarmed public health officials and clinicians.
The American Cancer Society reports that diagnoses among people younger than fifty increase by nearly three percent each year. In contrast, rates among those older than fifty continue to decline, largely because of widespread screening through colonoscopy.
Colorectal cancer has traditionally been considered a disease of older adults, but that pattern is shifting. Experts say lifestyle factors, including diet, obesity, and alcohol consumption, may be contributing to the rise in younger populations.
Former Surgeon General Dr. Vivek Murthy has called for stronger public warnings about alcohol, citing its link to cancer. Alcohol use causes nearly one hundred thousand cancer cases and about twenty thousand cancer deaths annually in the United States, Murthy has said.
Health officials note that many people remain unaware that alcohol is a carcinogen. Unlike tobacco, alcoholic beverages do not carry prominent cancer warnings in the United States.
Quitting Alcohol May Reduce Precancerous Polyp Risk
Colorectal cancer risk often begins as polyps, small clumps of cells that form inside the colon or rectum. Most polyps cause no symptoms, which is why routine screening plays a critical role in prevention.
Adenomas, a common type of polyp, are considered precancerous. While not all adenomas become cancerous, some can take up to fifteen years to develop into cancer if left untreated.
“With a colonoscopy, doctors can find and remove polyps before they have the chance to turn into cancer,” the American Cancer Society says.
The new research offers a hopeful message for heavy drinkers. Investigators found that stopping alcohol use may lower the risk of developing nonadvanced adenomas, while continued heavy drinking increases that risk.
Researchers emphasized that reducing or eliminating alcohol intake, combined with regular screening, could significantly cut colorectal cancer risk, especially for people with long-term drinking habits.
Public health experts say the findings strengthen the case for clearer guidance on alcohol consumption and earlier screening discussions, particularly as colorectal cancer increasingly affects younger adults.
