Ultra-processed food consumption and risk of oesophagus, stomach, and pancreatic cancers: a multi case–control study

Background: A high consumption of ultra-processed foods (UPF) has been associated with higher risk of gastrointestinal cancers, although this relationship has been insufficiently investigated. We evaluated the association between UPF consumption and oesophageal, stomach, and pancreatic cancers in a multi-case control study conducted in a Mediterranean area of Spain. Methods: = 161) cancers, and 452 controls. Diet was assessed five years before the interview using validated food frequency questionnaire. UPF consumption was estimated in grams/day and as a percentage of total dietary intake using the NOVA classification system and then categorised in tertiles. Multinomial logistic regression was applied to estimate relative risk ratios (RRR) and 95% confidence intervals (CI) adjusting for potential confounders. Results: UPF consumption in grams/day was positively associated with oesophageal and stomach cancers. Compared with the lowest tertile, the highest tertile of UPF consumption was associated with higher risk of oesophageal cancer (RRR = 2.29; 95% CI: 1.37-3.82) and stomach cancer (RRR = 1.56; 95% CI: 1.08-2.27). For stomach cancer, the highest consumption of ultra-processed dairy products (RRR = 2.10; 95% CI: 1.43-2.82) and sweets/pastries (RRR = 1.76; 95% CI: 1.24-2.50) showed increased risks. Ultra-processed drinks and pre-cooked foods were associated with higher risk of oesophageal cancer. No associations were observed for pancreatic cancer. Conclusion: Higher UPF consumption was associated with increased risk of oesophageal and stomach cancers, particularly linked to specific UPF categories. Further research is recommended to confirm these results.