Results of New Harvard, Tufts Study Link Colorectal Cancer in Men to Ultra-Processed Foods

Processed meats and products high in added sugars and low in fiber contribute to weight gain and obesity, which is an established risk factor.

Men who consumed high rates of ultra-processed foods had a 29% higher risk for developing colorectal cancer than men who consume smaller amounts of ultra-processed food, according to the results of a study published in The BMJ.

The same association was not found in women, according to the investigators from Tufts University and Harvard University.

“We started out thinking that colorectal cancer could be the cancer most impacted by diet compared to other cancer types,” Lu Wang, a postdoctoral fellow at the Friedman School of Nutrition Science and Policy at Tufts University, said in a statement.

“Processed meats, most of which fall into the category of ultra-processed foods, are a strong risk factor for colorectal cancer. Ultra-processed foods are also high in added sugars and low in fiber, which contribute to weight gain and obesity, and obesity is an established risk factor for colorectal cancer,” Wang said.

Investigators analyzed responses from 159,907 women and 46,341 men across 3 prospective studies, assessing dietary intake and conducted over more than 25 years.

Individuals were provided with a food frequency questionnaire every 4 years and asked about the frequency of consumptions of approximately 130 foods. The intake of ultra-processed foods was classified into quintiles, ranging from lowest consumption to highest, with the highest defined as the most at risk for developing colorectal cancer.

Although investigators found a clear link for men, the study did not find an overall increased risk for women.

Additionally, the results of the analyses showed the differences in the ways that men and women consume ultra-processed foods and the prospective associated cancer risk.

Of the individuals in the study, investigators noted 1294 cases of colorectal cancer among men and 1922 among women.

Investigators also found the strongest association between colorectal cancer and ultra-processed foods among men were in those who ate fish-based, meat, or poultry ready-to-eat products.

Additionally, they found that the consumption of sugar-sweetened beverages, such as fruit-and sugary milk-based drinks and soda, is also associated with an increased risk of colorectal cancer in men.

“We found an inverse association between ultra-processed dairy foods like yogurt and colorectal cancer risk among women,” Fang Fang Zhang, MD, PhD, a cancer epidemiologist and interim chair of the Division of Nutrition Epidemiology and Data Science at the Friedman School, said in the statement.

Further research is needed to determine if there is a true sex difference in the association, investigators said.

Although ultra-processed foods are often associated with poor diet quality, there could also be other factors beyond ultra-processed foods that could affect the development of colorectal cancer.

“Researchers continue to examine how nutrition-related policies, dietary recommendations, and recipe and formula changes, coupled with other healthy lifestyle habits, can improve overall health and reduce cancer burden. It will be important for us to continue to study the link between cancer and diet, as well as the potential interventions to improve outcomes,” Wang said.


New study links ultra-processed foods and colorectal cancer in men. News release. EurekAlert. August 31, 2022. Accessed September 2, 2022.