Overview
- The JAMA Oncology study followed 29,105 female nurses from 1991 to 2015, all of whom had at least two lower endoscopies before age 50 and repeated diet surveys every four years.
- Higher intake was associated with conventional adenomas, which are more often tied to early-onset colorectal cancer, with no link found for serrated lesions.
- The association persisted after accounting for body mass index, Type 2 diabetes and low fiber intake, supporting a signal independent of these risk factors.
- Participants averaged 5.7 daily servings of ultra-processed foods (about 35% of calories), with sugary or artificially sweetened drinks and packaged sauces, spreads and condiments highlighted in coverage.
- Authors caution that the observational design and a predominantly white female cohort limit generalizability, and they call for replication, clearer food classification and mechanistic research as screening now begins at age 45 in the U.S.