What people eat after a cancer diagnosis is often framed in terms of nutrients or calories. New research suggests that how processed food is may also matter for long-term outcomes.
A large observational study of cancer survivors in Italy found that higher consumption of ultraprocessed foods was associated with an increased risk of death from any cause and from cancer specifically. The findings were published in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.
Researchers analyzed data from the Moli-sani Study, a prospective cohort that has followed adults living in southern Italy since 2005. Among more than 24,000 participants, the team identified 802 cancer survivors who had provided detailed dietary information and were tracked for a median of 14.6 years.
During follow-up, 281 deaths occurred. Cancer survivors whose diets contained the highest proportion of ultraprocessed foods, measured by weight, had a 48% higher rate of death from any cause and a 57% higher rate of death from cancer compared with those whose diets contained the lowest proportion. Similar associations were observed when ultraprocessed food intake was measured by calories for cancer-related deaths, though not for all causes.
Ultraprocessed foods were classified using the NOVA system, which groups foods based on the extent and purpose of industrial processing rather than nutrient content alone. The researchers accounted for a wide range of factors that could influence survival, including age, sex, smoking status, body mass index, physical activity, medical history, cancer type and overall diet quality as measured by adherence to a Mediterranean-style eating pattern.
Notably, the association between ultraprocessed food intake and mortality persisted even after adjusting for overall diet quality. This suggests that the relationship may not be explained solely by lower nutrient density but could also reflect features of industrial processing itself.
To explore potential biological pathways, the researchers examined inflammatory, metabolic and cardiovascular biomarkers collected from participants. Adjusting for markers of inflammation and resting heart rate reduced the strength of the association by about one-third, suggesting these factors may partially explain the link between higher ultraprocessed food intake and mortality.
The study also looked at different categories of ultraprocessed foods, including sweetened beverages, processed meats, savory snacks and sugary foods. Some categories showed stronger associations than others, but the authors caution that ultraprocessed foods are best understood as a dietary pattern, not as isolated items.
Lead author Marialaura Bonaccio, a nutritional epidemiologist at IRCCS Neuromed in Italy, emphasized that the findings do not imply that any single food determines outcomes. Instead, they point to the importance of overall eating patterns and the cumulative role of food processing.
Because the study is observational, it cannot prove that ultraprocessed foods directly cause higher mortality. Dietary data were self-reported, eating habits may have changed over time and diet was assessed an average of more than eight years after cancer diagnosis. The researchers also note limited information on cancer stage at diagnosis and a relatively small number of deaths.
Even with these limitations, the findings add to growing evidence that the level of food processing may influence long-term health, particularly for people living with or beyond cancer. The results highlight the need for further research to clarify mechanisms and to understand how dietary patterns after diagnosis interact with treatment, recovery and survivorship.
This study was funded by the Fondazione AIRC per la Ricerca sul Cancro ETS.