Study Links Ultraprocessed Foods to Higher Risk of Early-Onset Colorectal Cancer

Consuming higher amounts of ultraprocessed foods may significantly increase the risk of developing precursors to early-onset colorectal cancer, according to a comprehensive new study from Mass General Brigham.

Researchers analyzed over two decades of dietary data and endoscopy results from nearly 30,000 women born between 1947 and 1964 who participated in the Nurses’ Health Study II. All participants underwent at least two lower endoscopies before turning 50 and completed dietary questionnaires about their ultraprocessed food consumption every four years.

The findings, published in JAMA Oncology, revealed a striking connection: women who consumed the most ultraprocessed foods—averaging 10 servings daily—had a 45% higher risk of developing adenomas compared to those who ate the least (about three servings daily).

Adenomas are growths in the colon or rectum lining that, while benign, are considered precancerous polyps and potential early warning signs of colorectal cancer.

“Our findings support the importance of reducing the intake of ultraprocessed foods as a strategy to mitigate the rising burden of early-onset colorectal cancer,” said Dr. Andrew Chan, senior author and chief of the Clinical and Translational Epidemiology Unit at Mass General Brigham Cancer Institute. “The increased risk seems to be fairly linear, meaning that the more ultraprocessed foods you eat, the more potential that it could lead to colon polyps.”

Ultraprocessed foods encompass ready-to-eat items containing high levels of sugar, salt, saturated fat, and food additives. While previous research has established links between these foods and overall colorectal cancer risk, this is the first study to connect them specifically with early-onset forms of the disease.

What strengthens the credibility of these findings is the researchers’ careful accounting for other colorectal cancer risk factors. “We had detailed information about other colorectal cancer risk factors in the participants, such as body mass index, type 2 diabetes and low fiber intake,” Dr. Chan explained. “Even after accounting for all these other risk factors, the association with ultraprocessed foods still held up.”

However, the researchers caution that diet alone doesn’t fully explain the increasing rates of early-onset colorectal cancer. “We see many individuals in our clinic with early onset colon cancer who eat very healthy diets,” noted Dr. Chan. “Identifying other risk factors for early onset colorectal cancer is one of the focuses of the work that we’re leading here at the Mass General Brigham Cancer Institute.”

Dr. Marc Siegel, a Fox News senior medical analyst not involved in the research, pointed out that while the study is observational and cannot prove causation, it aligns with emerging understanding about inflammatory processes and cancer development.

“It is disarray of metabolism, especially when accompanied by inflammatory chemicals that can form the precursors of cancer, including colon cancer,” Dr. Siegel explained.

The study received funding from several prominent institutions, including Cancer Research UK, the National Institutes of Health/National Cancer Institute, and the American Cancer Society.

The findings take on particular significance given the prevalence of colorectal cancer in the United States, where it ranks as the third most common cancer and second leading cause of cancer death. Health authorities expect approximately 154,000 new cases and about 52,900 deaths from colorectal cancer in 2025.

As research continues to identify risk factors for early-onset colorectal cancer, these findings suggest that dietary changes—particularly reducing ultraprocessed food consumption—could play an important role in prevention strategies for this increasingly common and deadly disease.