Consumption of ultra-processed foods and beverages may increase the risk of colorectal cancer. This was the conclusion of a major study by the Barcelona Institute for Global Health (ISGlobal), a center supported by the “la Caixa” Foundation, based on food behavior questionnaires completed by around 8,000 people in Spain. The study, the first of its kind in the country, also analyzed the link between ultra-processed food and drink products and two other cancers; although no association was found with prostate cancer, in terms of breast cancer a higher risk was observed in the existing and current subgroup of smokers who reported a normal diet. was high in ultra-processing products.
Social, economic and industrial changes have led to an increase in the consumption of processed foods and beverages, which currently account for between 25% and 50% of total dietary energy in Europe and future countries. into high and middle. Nova’s classification system divides food and drink into four categories according to how they are processed. Ultra-processed foods – the most processed – are industrial formulations with more than five ingredients that contain additives such as sugar, fat, salt and additives. Examples of products in this category include sugary soft drinks, ready meals and industrial bakery products.
Several studies have linked the consumption of ultra-processed foods and beverages to health risk factors, cardiovascular disease, type 2 diabetes and an increased risk for premature death. There are only a few studies on the relationship between these food products and cancer and the results are not entirely conclusive. A French study found an association between the consumption of ultra-processed foods and an increased risk of cancer. A study in Canada found an increased risk of developing prostate cancer with a higher intake of processed foods, but not with ultra-processed foods.
The aim of this study was to assess whether consumption of ultra-processed foods and beverages is associated with an increased risk of colorectal, breast or prostate cancer. To this end, the researchers conducted a case-control study of 7,843 adults living in different Spanish regions: half of the participants had colorectal cancer (1,852), breast cancer (1,486) or prostate cancer ( 953); and the other half were people with the same characteristics who did not have cancer. Data were obtained from the MCC-Spain multicase-control study. Diet data were collected using a validated questionnaire designed to assess the frequency of consumption of normal food and beverage items over a year. The results were then classified according to processing rate using Nova classification.
The study, published in Clinical nutrition, concluded that consumption of ultra-processed foods and beverages is associated with an increased risk for colorectal cancer: a 10% increase in consumption of ultra-processed foods and beverages was linked to an 11% increase in the risk of developing cancer colorectal.
Dora Romaguera, the study’s first author and researcher at ISGlobal, the Institut d’Investigació Sanitària Illes Balears (IdISBA) and the CIBEROBN, says this relationship can be explained, in part, “by the low level of fiber, fruits and vegetables, which are known to offer protection against colorectal cancer, among people who eat a lot of ultra-processed foods, but also with the additives and other products with carcinogenic potential that are most commonly used in processed food products. “
For breast cancer, no strong relationship was found, but association was observed in the group of mainstream and former smokers. Romaguera explains that “smoking is a risk factor for breast cancer, and smoking and certain dietary factors, such as consumption of ultra-processed foods and beverages, are known to have synergetic effects on cancer development. “
No link was found between prostate cancer and a diet high in ultraviolet products. “This finding is not surprising and is consistent with the results of previous studies on diet factors and prostate cancer risk, in which no link has been found,” adds Romaguera.
Cases of colorectal and breast cancer: a less healthy diet
The results of the study showed that people with breast and colorectal cancer, but not those with prostate cancer, reported a less healthy diet than people without cancer in the control group. “We found differences in their intake of energy, fiber, energy density and saturated fatty acids. Consumption of ultra-processed foods and beverages was higher among colorectal and breast cancer cases than in the controls ”, says ISGlobal researcher Sílvia Fernández, co – author of the study ‘s first author.
The food groups that made up the largest proportion of ultra-processed food consumption were sugary drinks (35%), sugary products (19%), ready-to-eat food (16%) and processed meat (12%). %). Processed meat has already been classified as carcinogenic by the International Agency for Research on Cancer (IARC). However, according to Pilar Amiano, a researcher at the Guipúzcoa Public Health Service, who coordinated the study: “ultra-processed foods and beverages in general are not yet classified as carcinogenic because the IARC’s goal was not to assess instead of focusing on the overall risk of an individual ‘s diet, but instead focusing on specific potentially dangerous components, such as processed meat ”.
She also says that, based on the results of this study and the current scientific evidence on the health risks associated with ultra-processed foods and beverages, particularly in relation to cancer, the authors believe that “food and public health policies and the IARC should already take into account food processing and discourage the consumption of ultra-processed products”.
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 Reocío . , 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-Lozano-Lozano Guillermo Fernández-Tardón, Gemma Castaño-Vinyals, Beatriz Pérez-Gómez, Antonio J. Molina, Javier Llorca, Leire Gil, Jesús Castilla, Marina Pollán, Manolis Kogevinas, Pilar Amiano. Measure ultra-processed foods and beverages and colorectal, breast and prostate cancers. Clinical nutrition, March 2021.