WEDNESDAY, Nov. 19, 2025 (HealthDay News) -- Higher ultraprocessed food (UPF) intake is associated with an increased risk for early-onset colorectal conventional adenomas, according to a study published online Nov. 13 in JAMA Oncology.Chen Wang, M.D., from the Harvard T.H. Chan School of Public Health in Boston, and colleagues evaluated the association between UPF consumption and the risk for early-onset colorectal cancer precursors. The analysis included 29,105 female participants in the Nurses’ Health Study II followed for 24 years.The researchers identified 1,189 cases of early-onset conventional adenomas and 1,598 serrated lesions. Those with higher UPF intake had a higher risk for early-onset conventional adenomas (highest versus lowest intake: adjusted odds ratio [AOR], 1.45; 95 percent confidence interval [CI], 1.19 to1.77; overall P < 0.001). However, there was no association with serrated lesions (AOR, 1.04; 95 percent CI, 0.89 to 1.22; P = 0.48 for trend). When further adjusting for body mass index, type 2 diabetes, dietary factors (fiber, folate, calcium, and vitamin D), and Alternative Healthy Eating Index–2010 scores, the findings persisted."These are very important findings for women because over the last decade, colorectal cancer among women has risen to the second leading cause of cancer death in women under 50," Christine Molmenti, Ph.D., M.P.H., associate professor and cancer epidemiologist at Northwell Health in New York, said in a statement. "Women are at particular risk for right-sided cancers and certain types of precancerous lesions called serrated polyps and also adenomas. But we want to raise awareness to women to prevent colorectal cancer through screening and through lifestyle. And this study really focuses on lifestyle and how diet may play a particular role and critical role in the early stages of carcinogenesis."Several authors disclosed ties to the pharmaceutical industry.Abstract/Full Text (subscription or payment may be required) .Sign up for our weekly HealthDay newsletter