Shocking Rise in Colon Growths Linked to Packaged “Convenience” Foods
Scientists at Mass General Brigham have found that a high intake of so‑called ultraprocessed foods may be connected to a substantial increase in precursors to early‑onset colorectal cancer. According to their research, those who eat large amounts of ready‑to‑eat foods filled with sugar, salt, saturated fat and food additives are significantly more likely to develop adenomas — growths in the colon or rectum that may become cancerous — by age 50.
The study tracked nearly 30,000 women born between 1947 and 1964, all of whom took part in the Nurses’ Health Study II. Each completed at least two lower‑endoscopy procedures before turning 50 and answered dietary questionnaires every four years about their consumption of ultraprocessed foods. Researchers found that participants who reported consuming about ten servings of these foods per day had a 45 percent higher risk of developing adenomas compared with participants whose intake was about three servings per day.
Adenomas are non‑cancerous polyps that form in the lining of the colon or rectum, but they are recognized as early‑warning precancerous lesions. Although benign themselves, they can indicate elevated risk of future colorectal cancer. The findings were published in JAMA Oncology.
Study findings and implications
Lead author Andrew Chan, chief of the Clinical and Translational Epidemiology Unit at Mass General Brigham, described the correlation as fairly linear: “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.” He added, “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.”
Previous research has linked ultraprocessed foods with colorectal cancer in general, but this is the first major study to focus specifically on the early‑onset form of the disease. One of the strengths of the study was its ability to adjust for multiple known risk factors — including body‑mass index, type 2 diabetes and low fibre intake — yet the association with ultraprocessed foods remained robust. “Even after accounting for all these other risk factors, the association with ultraprocessed foods still held up,” Chan stated.
However, the research team emphasised that ultraprocessed food consumption does not offer a full explanation for why early‑onset colorectal cancer is increasing. Chan admitted: “Diet isn’t a complete explanation for why we’re seeing this trend — we see many individuals in our clinic with early onset colon cancer who eat very healthy diets.” The team is continuing work to identify other risk factors and to refine how different types of ultraprocessed foods might vary in harmful potential.
External commentary underlined the limits of the research. Marc Siegel, a senior medical analyst with Fox News who was not involved in the study, described it as “observational, so it can’t prove causation, but it is very exciting, because it fits in with what is becoming clearer …” He pointed out that metabolic dysfunction and chronic inflammation may play roles in allowing precancerous changes to develop in the colon.
“It is disarray of metabolism, especially when accompanied by inflammatory chemicals that can form the precursors of cancer, including colon cancer.”
He also noted a caveat: “It may not be for all people … Delayed gastric emptying, which accompanies these drugs, could be a carcinogenic factor with some patients, perhaps those with inflammatory bowel disease.”
The study was supported by grants from multiple organisations including Cancer Research UK, the National Cancer Institute (part of the National Institutes of Health) and the American Cancer Society.
In the United States, colorectal cancer ranks as the third‑most common cancer and is the second leading cause of cancer death. In 2025 an estimated 154,000 new cases and about 52,900 deaths are expected.
Conclusion
Taking into account the data from nearly 30,000 women over 24 years, the research from Mass General Brigham reveals a strong association between high daily consumption of ultraprocessed foods and increased risk of early‑onset colorectal adenomas. While it does not establish direct causation and cannot explain all factors driving the rise of colorectal cancer in younger adults, it underscores the potential role of diet — specifically frequent intake of convenience‐style, highly processed foods — in tumour precursor development.
