Do Ultra-Processed Foods Cause Colon Cancer? New Study Reveals Surprising Findings

According to a large American study published recently in the scientific journal PLOS Medicine, eating more ultra-processed foods does not necessarily increase the risk of developing colorectal cancer.

The study, led by Erika Loftfield of the U.S. National Cancer Institute, followed 461,682 Americans who were between the ages of 50 and 71 when they enrolled in the research in 1995 and 1996. At the beginning of the study, participants completed a food frequency questionnaire, which researchers used to estimate their consumption of ultra-processed foods. Follow-up continued until 2018, with an average duration of approximately 18.8 years.

The researchers found no overall association between the total amount of ultra-processed food consumed and the incidence of colorectal cancer. "We did not find an association between overall ultra-processed food intake and colorectal cancer incidence," Loftfield said.

Why the Type of Ultra-Processed Food Matters

The findings became more nuanced when researchers examined individual food categories and their nutritional components.

Higher consumption of whole grains, dietary fiber, dairy products, and calcium from ultra-processed foods was associated with a lower incidence of colorectal cancer. In contrast, higher consumption of meat from ultra-processed food sources was associated with a greater incidence of the disease.

An additional analysis found that replacing 10% of the weight of ultra-processed foods in the diet with minimally processed foods was associated with a 2% reduction in colorectal cancer incidence.

These findings suggest that the nutritional composition of individual foods may be more informative than the broad classification of a product as "ultra-processed."

According to a statement published by PLOS Medicine, the results are consistent with existing dietary recommendations for colorectal cancer prevention, which emphasize whole grains, fiber, and calcium-rich foods while recommending limits on processed meat consumption.

Important Limitations of the Study

Despite the study's large number of participants and extensive follow-up period, the researchers acknowledged several important limitations.

Most participants were older White Americans, meaning the findings may not necessarily apply to younger adults or more diverse populations.

In addition, dietary habits were assessed only once, at the beginning of the study. As a result, researchers could not account for changes in participants' eating habits over the following decades.

Another limitation is that ultra-processed foods became increasingly available and varied throughout the study period, meaning participants' actual consumption may have been higher than the original estimates suggested.

This was an observational study, and therefore cannot establish that particular foods directly cause or prevent colorectal cancer. The findings are especially relevant however, given that ultra-processed foods account for more than half of the calories consumed by adults in the United States.

Overall, the research highlights the importance of looking beyond food processing labels and considering the nutritional quality of what people eat. Rather than treating all ultra-processed foods as equally harmful, the findings suggest that specific ingredients and food categories may play a more meaningful role in colorectal cancer risk.