A new large-scale study conducted in the US, published in the medical journal Cancer, has found that long-term and heavy alcohol use throughout life significantly increases the risk of developing rectal cancer, especially colorectal cancer.

Researchers analyzed data from more than 88,000 adults, who were followed for an average of 14-20 years and concluded that people who regularly drink more than 14 alcoholic drinks per week—about two drinks per day—are about 25% more likely to develop rectal cancer than those who drink less than one drink per week.

Among heavy drinkers, the risk of developing colorectal cancer was almost double that of people who drank less alcohol. This effect was especially pronounced among those who continued to be heavy drinkers into adulthood; they had a 91% higher risk of developing rectal cancer than light and moderate drinkers.

Notably, moderate alcohol consumption—7 to 14 glasses per week—did not increase the risk and was in some cases associated with a lower incidence of the disease, particularly in distal rectal cancer. However, the aforesaid researcher caution that this may be due to other lifestyle factors and does not indicate a direct protective effect of alcohol.

Furthermore, those who abstained from alcohol were significantly less likely to develop precancerous lesions than light drinkers, suggesting the potential benefit of quitting alcohol even in adulthood.