Key finding: ultra-processed foods may raise precancerous polyp risk
A new study published in JAMA Oncology suggests that higher consumption of ultra-processed foods could be linked to an increased risk of precancerous colorectal growths, particularly among women under 50. The research analyzed dietary patterns and colonoscopy results from a large group of participants to explore whether ultra-processed items play a role in the development of polyps that may precede colorectal cancer.
What counts as ultra-processed?
Ultra-processed foods (UPFs) are typically ready-to-eat or heat-and-serve products made with industrial formulations. They often contain high levels of added sugars, unhealthy fats, salt, and artificial additives, and they tend to be low in whole fruits and vegetables. Common UPF examples include packaged snacks, sweetened beverages, processed meats, and many ready meals. The study emphasizes examining these foods as a dietary pattern rather than focusing on single items.
The study: who was examined and how
Researchers followed 29,105 participants over several years, tracking dietary intake through validated food questionnaires and recording colonoscopy results to identify the presence of precancerous polyps, also known as adenomatous polyps. By comparing UPF consumption levels with polyp detection, the team aimed to determine whether a higher UPF intake correlated with increased risk.
Why the findings matter for women under 50
Colorectal cancer screening guidelines typically target adults aged 45 and older, but precancerous polyps can develop earlier in some individuals. The study’s emphasis on women under 50 highlights a potential window where dietary choices might influence polyp formation. It adds to a growing body of literature suggesting that diet quality—especially the balance between ultra-processed foods and whole foods—could affect colorectal health long before traditional screening ages.
Possible mechanisms and interpretations
Scientists are exploring several theories for how UPFs might contribute to polyp development. These include inflammatory responses triggered by additives, imbalances in gut microbiota caused by highly processed ingredients, and the greater energy density often found in UPFs leading to weight gain and metabolic changes. While the study shows an association, it doesn’t prove causation, and researchers caution that many factors influence polyp risk, including genetics, overall diet quality, physical activity, and smoking status.
What this means for daily choices
For individuals aiming to lower colorectal risk, the findings underscore the potential benefits of reducing UPF intake and prioritizing whole, minimally processed foods. Practical steps include cooking at home more often, choosing fresh fruits and vegetables, whole grains, lean proteins, and water over sugar-laden drinks. Even modest shifts toward less processed foods can help improve overall diet quality and metabolic health, which are closely linked to cancer risk in the long term.
Limitations and next steps
As with many observational studies, there are limitations to consider. Dietary assessments rely on self-reporting, and participants’ UPF intake can change over time. The study’s cohort composition and follow-up duration influence the strength of its conclusions. Future research is needed to confirm these findings across diverse populations and to tease apart which specific UPFs drive the observed associations. Randomized trials focusing on whole-diet patterns could provide more definitive answers.
Bottom line
The new evidence adds to a cautious but meaningful message: reducing ultra-processed foods may support colorectal health, especially for women under 50 who are navigating dietary choices during midlife. While more research is needed to establish causality, prioritizing nutrient-dense, minimally processed foods remains a sound strategy for overall health and long-term cancer risk reduction.
