Ultra-processed food may not be the colorectal cancer villain it has been made out to be, according to a large new study from the National Cancer Institute. Researchers analyzing dietary data from 461,682 American adults found no association between total ultra-processed food intake and colorectal cancer incidence over nearly two decades of follow-up. The findings, published Oct. 15 in the journal PLOS Medicine, suggest the relationship depends on the type of ultra-processed food consumed, with whole-grain and dairy products linked to lower risk and processed meats linked to higher risk.
Ultra-Processed Food Study Followed Adults for 18 Years
The research team, led by former NCI investigator Erikka Loftfield, used data from the NIH-AARP Diet and Health Study, a large cohort of U.S. adults who were between 50 and 71 years old when the study began. Participants completed food frequency questionnaires estimating their intake of items classified under the NOVA system, which defines ultra-processed food as formulations made mostly from substances derived from foods, with little or no whole food content. The researchers tracked colorectal cancer diagnoses over approximately 18 years, documenting more than 10,000 cases during the follow-up period.
The question matters because ultra-processed products now account for more than half of the energy intake of adults in the United States, and earlier research had painted a mixed picture. A 2025 study reported that heavily processed items might raise colorectal cancer risk in women under 50, while a 2022 analysis found higher risk among men with the highest intake. The new analysis, by contrast, is one of the largest to examine the question, and it found no overall link between the total amount consumed and cancer incidence.
“We did not observe an association between total ultra-processed food intake and colorectal cancer incidence,” Loftfield said in a news release about the research. The team adjusted for demographic, lifestyle, and health-related factors, including physical activity, smoking, and alcohol consumption, in their statistical models.
Ultra-Processed Food Types Differ in Their Cancer Associations
When the researchers looked at specific food groups, a more detailed pattern emerged. Higher intake of reconstituted meat products, such as hot dogs, was associated with higher bowel cancer incidence. In contrast, higher intakes of frozen desserts and milk products, such as fruit yogurts, were associated with lower incidence, as were higher intakes of breakfast cereals and bread. The authors noted that the associations lined up with current dietary guidance for colorectal cancer prevention: higher whole-grain and dairy intake linked to lower risk, and higher meat intake linked to higher risk.
“Our findings support current dietary guidance to consume whole grains, fiber, dairy and calcium and avoid processed meat for colorectal cancer prevention,” the authors wrote in the paper. They cautioned that ultra-processed food should not be treated as a single monolith, since the category spans everything from sugary sodas to fortified whole-grain cereals.
The study also modeled what would happen if people swapped some of their processed intake for less processed options. Replacing 10 percent of ultra-processed food intake, measured by weight, with an equivalent amount of minimally processed food was associated with a 2 percent lower incidence of colorectal cancer, a small but statistically meaningful shift at the population level.
There are important limitations. The study cohort included primarily older, white Americans, so the findings may not generalize to younger or more diverse populations. Diet was measured only once at baseline, which means the analysis could not account for changing eating habits over time or the increasing availability of newer processed products. As with any questionnaire-based research, the study found associations and cannot establish cause and effect.
Experts not involved in the research said the scientists appear to be on the right track. Health specialists continue to advise a diet rich in fruits, vegetables, whole grains, and calcium-rich foods to lower colorectal cancer risk. The takeaway, the researchers say, is that the nutritional content and food category may matter alongside the degree of processing, and that blanket claims about all processed items deserve a second look.