A recent Mass General Brigham study suggests that regularly eating ultraprocessed foods — typically ready-to-eat items high in sugar, salt, saturated fat and additives — may raise the risk of developing early signs of colorectal cancer at a younger age.
Researchers reviewed over 20 years of dietary data and endoscopy results from nearly 30,000 women born between 1947 and 1964.
All participants in the Nurses’ Health Study II had undergone at least two lower endoscopies before age 50 and completed food questionnaires every four years to track their intake of ultraprocessed items.
Those who consumed the most ultraprocessed foods — around 10 servings per day — showed a 45% higher likelihood of developing adenomas compared to women who ate the least (about three servings daily).
Adenomas are non-cancerous growths in the colon or rectum, but they are considered a warning sign because they can develop into colorectal cancer over time.
Findings were published in JAMA Oncology.
Senior researcher Andrew Chan, chief of the Clinical and Translational Epidemiology Unit and gastroenterologist at the Mass General Brigham Cancer Institute, emphasized that their analysis supports reducing ultraprocessed food intake to help combat rising rates of early-onset colorectal cancer. He noted that the risk appears to increase steadily alongside higher consumption.
This study is the first to specifically associate ultraprocessed foods with early-onset colorectal cancer precursors. Researchers accounted for other known risk factors — including body mass index, Type 2 diabetes and low fiber intake — and still found the link remained strong.
However, they also acknowledged that diet alone doesn’t explain the growing trend. Some individuals with healthy eating habits still develop the disease, suggesting additional causes are likely at play.
The research was partially funded by Cancer Research UK, the National Institutes of Health/National Cancer Institute and the American Cancer Society.
Colorectal cancer remains the third-most common cancer in the U.S. and the second leading cause of cancer-related deaths. Projections estimate 154,000 new diagnoses and approximately 52,900 deaths in 2025.
