Mediterranean Diet and Risk of Pancreatic Cancer-Is It Worth Investigating More? An Updated Systematic Review and Dose-Response Meta-Analysis of Prospective Cohort Studies.

BACKGROUND: Despite previous meta-analysis studies on the association between adherence to the Mediterranean diet and risk of pancreatic cancer, there has not been a comprehensive and updated study reviewing all studies with inclusion criteria. Despite advances in cancer treatment and control, pancreatic cancer is still one of the deadliest malignancies, and the mortality rate is consistent with its prevalence. Therefore, this updated systematic review and dose-response meta-analysis study was conducted to examine the association between one of the healthiest dietary patterns, the Mediterranean dietary pattern, and the rate of pancreatic cancer. METHODS: Using relevant keywords, electronic searches for prospective cohort studies were conducted in Web of Science, PubMed, and Scopus until March 17, 2025. The reported hazard ratios (HRs) in the primary studies were regarded as the main effect size. The overall effect was calculated using a random-effects model that accounts for between-study variability. RESULTS: Based on 10 prospective studies, we found that people who adhered more strictly to the Mediterranean diet had a lower risk of developing pancreatic cancer (pooled HR: 0.90; CI: 0.82-0.98; I2 = 46.72%, p-value = 0.05). Also, outcome types had different effects in subgroup analyses. In the incidence and mortality of pancreatic cancer, there was a significant reduction, but this reduction was not significant in the risk of pancreatic cancer. Our dose-response analysis showed no evidence of a linear association; however, it indicated that following a Mediterranean dietary pattern may have a non-linear effect on the risk of pancreatic cancer, reducing it (P-nonlinearity = 0.04). CONCLUSION: The present systematic review and dose-response meta-analysis of prospective cohort studies provides compelling evidence for an inverse relationship between adherence to the Mediterranean diet and the risk of pancreatic cancer. REGISTRY AND REGISTRY NUMBER FOR SYSTEMATIC REVIEWS OR META-ANALYSES: The study's protocol was registered in the international prospective registry of systematic reviews (URL: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=423150 and Registration ID: CRD42023423150).