The Link Between Colorectal Cancer and Ultra-Processed Foods

A recent study published in the Journal of Clinical Nutrition indicates there’s more at stake than our waistlines when it comes to ultra-processed foods and drinks. Results of a large study done by the Barcelona Institute for Global Health (ISGlobal) found that intake of ultra-processed foods and drink may raise the risk of colorectal cancer. While no link was seen with prostate cancer, higher risk was observed for breast cancer in a subgroup of former and current smokers who reported consuming more ultra-processed foods.Intake of ultra-processed foods in Europe accounts for roughly 25-50% of total calorie intake in high and middle-income countries. Economic, industrial, and social changes have spurred a rise in ultra-processed food and drink intake. According to the Nova classification system, which groups food and drinks into four different categories based on processing procedures, ultra-processed foods are those that undergo the most processing. These products typically have more than 5 ingredients and usually contain added sugar, fats, salts, and additives. Sugary soft drinks, ready-made meals and mass-produced baked goods are examples of ultra-processed foods.This is not the first time that ultra-processed foods have made the news. Previous studies showed a link between ultra-processed foods and drinks and cardiovascular disease, type 2 diabetes, and even increased risk of early death. There haven’t been many studies to show the relationship of these foods with cancer. One French study indicated a link between ultra-processed food consumption and cancer risk and a Canadian study found higher risk of prostate cancer development with processed foods, but not with ultra-processed foods. The goal of the recent ISGlobal study was to evaluate whether intake of ultra-processed foods and drinks is linked with a higher risk of colorectal, breast, or prostate cancer. Researchers used a case-controlled study of over 7800 adults residing in various provinces in Spain: 50% of subjects had a diagnosis of colorectal, breast, or prostate cancer and the remaining subjects had similar characteristics without a diagnosis of cancer. A validated questionnaire from the multi-case control study MCC-Spain was utilized to collect data. Information on the frequency of intake of usual food and drink items for over a year were analyzed. Using the Nova classification system, results were then classified.Conclusions from the study were published in the Journal of Clinical Nutrition and indicated that intake of ultra-processed foods and drinks is linked with an increased risk of colorectal cancer. In fact, a 10% rise in the consumption of ultra-processed foods and drinks was associated with an 11% rise in the risk of development of colorectal cancer.Lead author and researchers a ISGlobal Dora Romaguera suggests that the relationship may be due to poor intake of fiber, fruits, and vegetables, all of which are known to be protective against colorectal cancer in those with a high intake of ultra-processed foods. Additives and other ingredients with carcinogenic potential may also raise the risk.While no strong link was found between ultra-processed food intake and breast cancer, a subset group of former and current smokers did have a higher risk. Consistent with previous studies, no link between ultra-processed foods and prostate cancer was noted. People with breast and colorectal cancer, but not prostate cancer reported less healthy diets than those without cancer in the control group. Differences were seen in terms of calories, fiber, and saturated fat intake. Intake of ultra-processed foods and drinks was higher in those with colorectal and breast cancer compared to controls, according to ISGlobal scientist Silvia Fernandez, another first author of the study. Foods that accounted for the biggest group of ultra-processed foods and beverages included sugary drinks (35%), sugary products (19%), ready-to-eat-foods (16%) and processed meats (12%). According to the International Agency for Research on Cancer (IARC), processed meats are already classified as carcinogenic. Pilar Amiano, a researcher at the Guipuzcoa Public Health Service that coordinated the study notes, “ “ultra-processed foods and drinks in general are not yet classified as carcinogenic because the aim of the IARC was not to assess the overall risk of an individual’s diet, but rather to focus on specific components that might be dangerous, such as processed meats”.Amiano believes that "food and public health policies and the IARC should already be taking food processing into account and discouraging the consumption of ultra-processed products” in lieu of the current evidence on health risks linked with ultra-processed foods and drinks, particularly cancer.How can you help your clients reduce their intake of ultra-processed foods? Here are some ideas:

• Swap seltzer water for soda to reduce intake of sugary soft drinks.
• Snack on nuts or seeds in place of chips.
• Eat seasonal fruit in place of ultra-processed baked goods.
• Reduce red and processed meats such as bacon, sausage, and lunch meats.
• Increase fiber intake with beans, whole grains, vegetables, and fruit.
• Read labels for additional additives that may be linked with cancer such as sodium nitrite and sodium nitrate.  

By Lisa Andrews, MEd, RD, LDReferences:

1. Dora Romaguera, Sílvia Fernández-Barrés, Esther Gracia-Lavedán, Eva Vendrell, Mikel Azpiri, Emma Ruiz-Moreno, Vicente Martín, Inés Gómez-Acebo, Mireia Obón, Amaia Molinuevo, Ujué Fresán, Ana Molina-Barceló, Rocío Olmedo-Requena, Adonina Tardón, Juan Alguacil, Marta Solans, Jose M. Huerta, José Manuel Ruiz-Dominguez, Nuria Aragonés, Tania Fernández-Villa, Trinidad Dierssen-Sotos, Victor Moreno, Marcela Guevara, Mercedes Vanaclocha-Espi, Macarena Lozano-Lorca, Guillermo Fernández-Tardón, Gemma Castaño-Vinyals, Beatriz Pérez-Gómez, Antonio J. Molina, Javier Llorca, Leire Gil, Jesús Castilla, Marina Pollán, Manolis Kogevinas, Pilar Amiano. Consumption of ultra-processed foods and drinks and colorectal, breast, and prostate cáncer. Clinical Nutrition, March 2021.https://doi.org/10.1016/j.clnu.2021.02.033.
2. Ultra-Processed Foods and Incident Cardiovascular Disease in the  Framingham Offspring Study. J Am Coll Cardiol 2021;77:1520-1531.
3. Eating highly processed foods may raise cancer risk - Harvard Health
4. Study links diet of ultra-processed foods to chronic disease risk | CBC News