Some Ultra-Processed Foods May Not Increase Bowel Cancer Risk, Study Suggests

Not all ultra-processed foods (UPFs) are associated with an increased risk of bowel cancer, and some commonly consumed items like cereals, flavored yogurts, supermarket bread, and baked beans may even lower the risk by up to 28 percent, according to new research. Conversely, ultra-processed meats such as hot dogs and bacon have been linked to an 8 percent higher chance of developing the disease.

The findings, published in the journal PLOS Medicine, stem from a study of 461,682 adults in the U.S. between the ages of 50 and 71 over an 18-year period. Researchers observed that while overall UPF consumption did not correlate with a higher likelihood of bowel cancer, specific categories showed distinct associations.

Bowel cancer is the second deadliest cancer in the UK, with over 48,200 cases and 17,700 deaths annually. Diagnoses among individuals under 50 have seen a significant surge since the early 1990s, increasing by over 50 percent.

Previous studies have consistently indicated a link between UPFs, characterized by artificial ingredients and high levels of fat and salt, and an increased risk of bowel cancer. One study from the previous year suggested that women frequently consuming UPFs were 45 percent more likely to develop potentially cancerous growths in the bowel. UPFs have also been associated with 32 serious health conditions, including heart disease and dementia.

In the recent study, each additional daily serving of processed meat was associated with an 8 percent increase in bowel cancer risk, compared to a 4 percent increase for non-UPF meat. In contrast, an extra daily serving of UPF dairy, such as sweetened yogurts or milkshakes, was linked to a 25 percent lower risk, surpassing the 10 percent reduction observed with non-UPF dairy sources. Consuming an additional serving of supermarket wholemeal bread daily was associated with a 13 percent lower risk, and an extra 10 grams per day of fiber from processed fibrous foods like baked beans correlated with a 28 percent drop in risk.

Authors of the study suggest that the presence of beneficial nutrients, such as fiber in breakfast cereals, wholemeal bread, and baked beans, may explain these protective effects. Fiber is a known factor in reducing bowel cancer risk.

However, the researchers emphasized limitations, noting that the study focused on older adults and its findings might not be universally applicable. Experts not involved in the study urged caution and highlighted that UPFs should not be viewed as a single homogeneous category. They also stressed that the results should not be generalized to younger populations, particularly given the rise in early-onset bowel cancer, which this study did not address.

The findings emerged on the same day a separate study in JAMA Network Open linked high UPF consumption to a 40 percent increased likelihood of vascular brain injury detected on MRI scans, a condition where brain tissue is damaged due to blood vessel issues. That study, involving 8,783 adults with an average age of 58, also noted its observational nature and the inability to prove causation, though it suggested a link between UPF intake and adverse brain health outcomes.