Ultra-processed foods and cancer risk: a narrative review of epidemiological findings and biological mechanisms

This narrative review explores the association between ultra-processed foods (UPFs) and cancer risk. UPFs, composed mainly of refined ingredients and additives with little or no whole food, accounting for 30-50% of daily caloric intake worldwide. Widespread use has raised major public health concern. This narrative review is based on literature searched in PubMed and EBSCOhost, emphasising peer-reviewed cohort and case-control studies, complemented by relevant mechanistic evidence. Epidemiological evidences indicates that higher UPFs intake is associated with increased incidence and mortality of several cancers, including colorectal, breast, liver, pancreatic and renal cell carcinoma, though findings for prostate and haematological cancers remain inconclusive. Proposed mechanisms include nutrient displacement, obesity-mediated pathways and processing-related exposures such as additives, neo-formed compounds and packaging contaminants. These factors contribute to inflammation, oxidative stress, metabolic dysfunction and gut microbiota disruption. Although causality is not fully established, converging evidence supports reducing UPFs consumption as part of cancer prevention strategies.