Lifetime alcohol consumption has been linked to a higher risk of colorectal cancer, according to a study published in the peer-reviewed journal CANCER by Wiley Online. The research reveals that individuals with higher lifetime alcohol consumption are at a greater risk of developing both colorectal and rectal cancer, and that quitting drinking can lower a person's risk.
The study analyzed data from US adults enrolled in the National Cancer Institute's Prostate, Long, Colorectal, and Ovarian (PLCO) Cancer Screening Trial, and found that 1,679 colorectal cancer cases occurred among 88,092 participants over 20 years of follow-up. Current drinkers with an average lifetime alcohol intake of 14 or more drinks per week had a 25% higher risk of developing colorectal cancer and a 95% higher risk of developing rectal cancer compared to those with an average lifetime alcohol intake of less than one drink per week.
The study also found that heavy drinking throughout adulthood was linked to a 91% higher risk of colorectal cancer compared to consistent light drinking. However, no evidence of increased colorectal cancer risk was observed among former drinkers, and former drinkers had lower odds of developing noncancerous colorectal tumors, or adenomas, than current drinkers averaging less than one drink per week.
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," said co-senior author Erikka Loftfield, PhD, MPH, of the NCI, part of the National Institutes of Health.
This study highlights the importance of moderating alcohol consumption to reduce the risk of colorectal cancer. It also emphasizes the potential benefits of quitting drinking for individuals who are at a higher risk of developing the disease. However, it is important to note that the study's findings should not be interpreted as a recommendation to abstain from alcohol, as moderate drinking may have health benefits. Further research is needed to fully understand the relationship between alcohol consumption and colorectal cancer risk.
