Ultra-processed foods linked to colorectal cancer risk in men

Photo credit – Wolfman via Creative Commons

CANCER DIGEST – Sept. 25, 2022 – Men who consumed large amounts of ultra-processed foods had a 29 percent higher risk of colorectal cancer than men who consumed less of such foods while the same correlation was not found in women, a new study shows.

Ultra-processed foods include convenience pre-cooked and instant meals that are also high in added sugars and low in fiber and tend to contribute to weight gain and obesity. These foods include such ready-to-eat products like sausage, bacon, ham, fish cakes.

The analysis included data from two long-running Nurses Health Studies and the Health Professionals Follow-up Study. Data was collected from 159,907 women and 46,341 men followed for more than 25 years. Among these participants there were 1,294 cases of colorectal cancer among men and 1,922 cases among women. The study was published Aug. 31, 2022 in the British Medical Journal (BMJ) .

The researchers divided the participants' consumption of ultra-processed food into five groups ranging from lowest to highest. They found that men who developed cancer tended to be among the group consuming the highest amounts of such foods, but the same was not found among the women participants.

In addition the researchers found that higher consumption of sugary beverages such as sodas, fruit-based beverages and sugary milk based beverages were also associated with higher colorectal cancer risk, however, there was an reverse association for ultra-processed dairy products such as yogurt.

“We found an inverse association between ultra-processed dairy foods like yogurt and colorectal cancer risk among women,” co-senior author Fang Fang Zhang, a cancer epidemiologist and interim chair of the Division of Nutrition Epidemiology and Data Science at the Friedman School said in a press release. "Foods like yogurt can potentially counteract the harmful impacts of other types of ultra-processed foods in women.”

Zhang added that the protective effect of such foods as yogurt may point to the potential role of food additives in altering gut microbiotics, promoting inflammation, and contaminants formed during food processing or migrated from food packaging may all promote cancer development.

Mingyang Song, co-senior author on the study and assistant professor of clinical epidemiology and nutrition at the Harvard T.H. Chan School of Public Health, added that, “Further research will need to determine whether there is a true sex difference in the associations, or if null findings in women in this study were merely due to chance or some other uncontrolled confounding factors in women that mitigated the association.”