Reference: JAMA Oncol. 2025 Nov 13:e254777
Practice Point: For female adults < 50 years old, higher intake of ultraprocessed foods, particularly beverages, is associated with increased odds of early-onset adenomatous colorectal polyps.
EBM Pearl: By adjusting for a comprehensive set of confounders, carefully accounting for multiple variables can strengthen causal relationships even in observational studies.
If you think early-onset colon adenomas are mostly about genetics, think again. A new analysis published in JAMA Oncology suggests that habitual ultraprocessed food (UPF) intake may quietly increase the risk of adenomatous polyps, the clinically important precursors to colorectal cancer. UPFs are highly manufactured products typically made from refined ingredients and additives, often containing little or no whole foods. Common examples of UPFs include packaged snacks, sugary cereals, breakfast pastries, ready-to-eat meals, soda, and other artificially sweetened beverages–you know, the foods in which even you can’t pronounce all the ingredients, and you’re the health professional in the family!
As part of the Nurses’ Health Study II, an ongoing United States prospective cohort of female registered nurses established in 1989, this investigation leveraged decades of dietary and endoscopy data to tease apart which foods may matter most when it comes to elevated risk of colon polyps. In this analysis, nearly 30,000 female nurses < 50 years old who had provided an in-depth dietary history and also had a lower endoscopy for screening or symptomatic purposes were evaluated for presence of colon polyps at the time of endoscopy and divided into quintiles of UPF intake.
Over a median follow-up of 13 years, 1,189 early-onset adenomatous polyps and 1,598 serrated lesions were diagnosed in the cohort. UPFs provided approximately 35% of total daily calories among all participants, with a median intake of 5.7 UPF servings per day, ranging from 3 to 10 UPF servings per day across the 5 quintiles. The risk of adenomatous polyps was UPF-intake dependent until about 7-8 servings per day, at which point the risk seemed to plateau. This UPF-associated increased risk was consistent across adenoma subtypes, sizes, and locations. Women with the highest UPF intake had 45% higher odds of developing adenomatous polyps compared with those in the lowest intake group (adjusted odds ratio 1.45, 95% CI 1.19-1.77), while no significant association was observed for serrated lesions. Results were similar when restricted to adenomas diagnosed before age 45 years. In subgroup analysis, sweetened beverages showed the strongest individual indication (adjusted odds ratio 1.21, 95% CI 1.01-1.46), though no single category accounted for the overall effect.
Sensitivity analyses, including lagged exposures and alternative UPF classifications, supported the findings. It’s important to note these findings suggest that while higher UPF intake may increase the risk of adenomatous polyps, they do not establish a direct link to colorectal cancer itself. Importantly, while UPFs contribute to excess caloric intake and weight gain (which are known early-onset colorectal cancer risk factors), the association with adenomatous polyps was present even after accounting for body mass index, type 2 diabetes, dietary factors (fiber, folate, calcium, and vitamin D), and Alternative Healthy Eating Index–2010 scores, indicating that part of the risk may operate independently of body weight or metabolic disease.
In the end, this study serves up a simple message with the subtlety of a microwave burrito: the degree of processing matters. For those of us providing preventive care for younger adults, these findings could provide actionable insight that is not just about diet and weight. While causality is not proven, the evidence reinforces the importance of diet in colorectal health. If UPFs are quietly stacking the odds toward early adenomas, then nudging patients toward meals that look like actual food and drinks, not ingestible chemistry sets, becomes more than lifestyle advice; it’s early intervention. Asking about processing isn’t a niche nutrition question anymore. It’s preventive medicine showing up a decade earlier than the colonoscope.
For more information, see the topic Colorectal Cancer Prevention in DynaMed.
DynaMed EBM Focus Editorial Team
This EBM Focus was written by Rich Lamkin, MPH, MPAS, PA-C, Clinical Writer at DynaMed. Edited by Alan Ehrlich, MD, FAAFP, Executive Editor at DynaMed and Associate Professor in Family Medicine at the University of Massachusetts Medical School; Katharine DeGeorge, MD, MS, Senior Deputy Editor at DynaMed and Associate Professor of Family Medicine at the University of Virginia; Dan Randall, MD, MPH, FACP, Senior Deputy Editor at DynaMed; Claire Symanski, PhD, Medical Editor and Team Lead for ENT at DynaMed; McKenzie Ferguson, PharmD, BCPS, Senior Clinical Writer at DynaMed; Matthew Lavoie, Senior Medical Copyeditor, BA, at DynaMed; Hannah Ekeh, MA, Senior Associate Editor II at DynaMed; and Jennifer Wallace, BA, Senior Associate Editor at DynaMed.