Study Links Common Herbicide to Rise in Young Colorectal Cancer Cases

A recent study indicates that a widely used weed killer may have a connection to the increasing rates of young colorectal cancer globally.

This groundbreaking research, published in the journal Nature Medicine, points to picloram—a herbicide designed to eliminate woody plants while preserving grasses—as a potential factor behind the uptick in colon and rectal cancer among individuals under 50 years old. Notably, the study found no significant correlation between picloram and colorectal cancer cases in adults aged 70 and above, who are generally the most affected.

• Smoking
• Poor dietary habits, particularly diets lacking fresh vegetables, beans, and nuts
• Obesity
• Educational status, often linked to dietary quality
• And, of course, the herbicide picloram

Developed in the 1960s, picloram was among the herbicides used by the U.S. military during the Vietnam War to clear forests. Its mode of action disrupts normal plant hormone functions and it can remain in the soil for many years.

Exploring Other Potential Links to Young Colon Cancer

This newly emerging research represents just a starting point in understanding environmental contributors to young colon cancer, which has been on a worrying rise for over thirty years. To address this trend, the U.S. recently adjusted its guidelines, lowering the recommended age for initial colon cancer screenings from 50 to 45.

Last year, yet another study hinted at a possible connection between early life infections from colibactin bacteria and the development of young colon cancer. Researchers speculate that specially designed probiotics might someday help counteract this risk.

Rebecca Siegel, a cancer epidemiologist at the American Cancer Society, noted the importance of this research. She stated that while more validation is needed to confirm these findings, they could shed light on new factors contributing to the cancer’s rise.

Meanwhile, Robin Mesnage, a visiting research fellow at King’s College London who studies the gut microbiome, commented on the study. He found it intriguing but cautioned that it does not establish a direct connection between picloram and young colon cancer, as exposure levels were not measured in the patients analyzed. He suggested that other chemicals mixed with picloram during its production might also play a role in its impact.

This ongoing investigation illustrates just how complex the causes of young colon cancer are and how various factors may intertwine in this troubling health trend.