Researchers from the National Cancer Institute analyzed data from 461,682 adults aged 50 to 71 who enrolled in the NIH-AARP Diet and Health Study between 1995 and 1996, following them until 2018 for a median of nearly 19 years, during which 10,075 colorectal adenocarcinoma cases were diagnosed.

According to Healthline, the team reported no association between overall ultra-processed food intake and colorectal cancer incidence — a finding published October 15 in PLOS Medicine that pushes back against the assumption that processing level alone determines cancer risk.

The result cuts against earlier research that alarmed both scientists and shoppers: Healthline notes a 2025 study suggested ultra-processed foods might raise colorectal cancer risk in females under 50, while a 2022 study found men eating high rates of these foods faced elevated risk.

The new finding matters because ultra-processed products now account for more than half of adults' energy intake in the United States, according to the NCI scientists, so any genuine risk signal would have sweeping dietary implications for how Americans are counseled to eat.

The nuance is that the category lumps together very different foods.

Healthline reports the NCI team found whole grains, fiber, dairy products, and calcium from ultra-processed sources were associated with lower colorectal cancer incidence, while meat from ultra-processed sources was associated with higher incidence.

Replacing 10% of gram weight from ultra-processed intake with minimally processed foods was tied to 2% lower incidence. As colorectal surgeon Ketan Thanki put it to Healthline, a whole grain cereal and a hot dog are both ultra-processed, but they push risk in opposite directions.

The definitional fight itself is under scrutiny.

The Examination reports that a new study in the American Journal of Public Health found 91% of research papers criticizing the NOVA classification system — the leading standard for defining ultra-processed foods — had at least one author with financial ties to the food industry, and that more than two-thirds of those authors failed to disclose the relationships.

Lead author Erica LaFata of the Oregon Research Institute told The Examination she hopes people pay attention to where these conversations are coming from.

While the colorectal result is a reprieve, other harms remain in play.

Medical Xpress reports a McMaster University-led study in JAMA Network Open that MRI-scanned nearly 9,000 Canadians aged 35 to 69 and found those eating the most ultra-processed food were 40% more likely to show silent brain damage — changes researchers say can precede stroke and memory problems, with the association nearly twice as strong among women.

Healthline notes separate research has connected these foods to heart disease, type 2 diabetes, and obesity.

For home cooks and health-conscious eaters, the practical advice from experts cited by Healthline is unchanged: emphasize fruits, vegetables, whole grains, and calcium-rich foods, and limit red and processed meats, sugary drinks, and refined grains.

The NCI researchers acknowledged their cohort was primarily older, white Americans and that intake was measured only once at baseline.

The American Cancer Society recommends average-risk adults start colorectal screening at age 45, and experts told Healthline that reading the ingredient label matters more than any processing label.