Research has shown that eating habits after treating and surviving cancer can affect long-term survival. In particular, the more ultra-processed foods consumed, the higher the risk of death from all causes, including cancer.
Ultra-processed foods often lack essential nutrients such as vitamins, minerals, and dietary fiber, and are characterized by the addition of various additives, artificial flavors, preservatives, emulsifiers, large amounts of added sugar, and unhealthy fats during the processing process.
“These ingredients can interfere with metabolic processes, disrupt the balance of intestinal microorganisms, and promote inflammation,” said Dr. Marialaura Bonaccio, a member of the epidemiology and prevention research team at the IRCCS Neuromed Institute in Italy. “As a result, even if the calorie content and nutritional composition are similar to those of minimally processed foods, they can still have a more harmful effect on our bodies.”
Researchers analyzed data from a cohort study of residents of the Molise region in southern Italy and examined the association between consumption of ultra-processed foods and risk of death in cancer survivors. The analysis targeted 24,325 adults who were 35 years or older at the start of the study, and included follow-up data from March 2005 to December 2022.
Among these, the researchers selected 802 cancer survivors (476 women, 326 men) with a history of cancer at baseline as the final analysis subjects. They provided detailed dietary information through the European Prospective Investigation into Cancer and Nutrition (EPIC) food frequency questionnaire.
The level of food processing was assessed using the NOVA classification system, which classifies foods into four levels according to the purpose and degree of processing. Ultra-processed food intake was calculated in two ways: △ the ratio of the weight of ultra-processed foods to the total weight of food and beverages consumed per day, and △ the ratio of calories from ultra-processed foods to the total calories consumed per day. The researchers divided the participants into three groups based on the weight ratio and analyzed them.
During the analysis process, we adjusted extensively for demographic factors such as age and gender, smoking status, body mass index, leisure-time physical activity, underlying disease, cancer type, and overall diet quality reflecting the Mediterranean diet score.
The more ultra-processed foods you eat, the higher your risk of death.
During an average follow-up period of 14.6 years, 281 of 802 cancer survivors died. The analysis found that people in the top third of ultra-processed food consumption had a 48% higher risk of death from all causes and a 59% higher risk of cancer death compared to the bottom third.
When analyzed based on the calorie content of ultra-processed foods, a similar trend was seen in the risk of cancer death. However, no statistically significant association was observed in deaths due to causes other than cancer.
Dr. Bonaccio explained, “Some foods are high in weight but low in calories, and conversely, some are high in calories but low in weight, so the results may vary depending on the indicator.” He continued, “Nevertheless, the fact that the increased risk of death remained even after taking into account overall diet quality suggests that it is not simply a matter of nutritional ingredients, but the industrial processing process itself may be an independent health risk factor.”
Inflammation and heart rate, a possible link
The researchers also analyzed biomarkers related to inflammation, metabolism, and cardiovascular disease to examine the biological mechanisms by which ultra-processed foods affect health. The results showed that after adjusting for inflammatory markers and resting heart rate, the association between ultra-processed foods and all-cause mortality was weakened by about 37 to 40 percent.
This suggests that increased consumption of ultra-processed foods may increase inflammatory responses and increase cardiovascular burden, which may contribute to increasing the risk of death in the long term. The researchers explained that this biological pathway may be particularly important in cancer survivors.
Dietary patterns are more important than individual foods
The research team analyzed ultra-processed foods by dividing them into seven categories: artificial/sweetened beverages, dairy products, cheese, processed meat, salty snacks, high-fat sauces, starchy foods, sugars, and desserts. Some of these were associated with an increased risk of death, but no consistent pattern emerged across all categories.
Dr. Bonaccio emphasized, “Rather than interpreting each individual ultra-processed food, it is better to approach the dietary pattern as a whole,” adding, “The most important message is not about specific foods, but how much ultra-processed food is consumed overall.”
As an action plan, he advised, “Overall, it is most effective to reduce the proportion of ultra-processed foods in the diet and switch to home-cooked meals made with fresh, minimally processed ingredients,” and added, “If there are more than five ingredients listed on the label or it contains at least one food additive, it is likely to be an ultra-processed food.”
The researchers made it clear that because this was an observational study, a causal relationship could not be determined. Other limitations were that the dietary information was self-reported, that eating habits may have changed during the follow-up period, and that there may be survival bias as the assessment was conducted an average of 8.4 years after cancer diagnosis. In addition, the relatively small number of deaths and the lack of stage information at the time of cancer diagnosis also require caution in interpretation.
The results of this study were published in Cancer Epidemiology, Biomarkers & Prevention under the title ‘Ultra-processed food and mortality among long-term cancer survivors from the Moli-sani Study: prospective findings and analysis of biological pathways’.
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Q1. What exactly are ultra-processed foods?
A. Ultra-processed foods are foods made through industrial processes, and often contain various types of additives, artificial flavors, preservatives, emulsifiers, etc. Representative examples include sweetened beverages, processed meats, snacks and desserts, ready-to-eat foods, and some sauces.
Q2. Is it dangerous to maintain a ‘healthy diet’ like the Mediterranean diet?
A. In this study, even after adjusting for overall diet quality, the higher the intake of ultra-processed foods, the higher the risk of death. This suggests that, independent of its nutritional composition, the processing itself may have negative health effects.
Q3. What is the most realistic way to reduce ultra-processed foods?
A. It helps to check food labels. If it has more than five ingredients or contains at least one food additive, it is likely to be an ultra-processed food. It is recommended that your diet focus on home-cooked meals made with fresh ingredients and minimally processed foods.
