Association between adherence to the Mediterranean Diet and pancreatic cancer risk: a systematic review and meta-analysis
Pancreatic cancer (PC) is one of the most lethal malignancies with a poor prognosis. Although the Mediterranean Diet (MedDiet) is hypothesized to be inversely associated with PC risk, epidemiological findings remain inconsistent. This meta-analysis aims to quantitatively evaluate the association between Mediterranean Diet adherence and the risk of developing pancreatic cancer by synthesizing the most recent evidence. A systematic search was performed across PubMed, Web of Science, Embase, and the Cochrane Library for observational studies investigating MedDiet and PC risk. Data were synthesized using both continuous and categorical variable analyses. Given the anticipated heterogeneity, a random-effects model was applied to pool the effect estimates. Fourteen studies (12 cohorts and 2 case-control studies) were eligible for inclusion. In the continuous analysis, a higher MedDiet adherence score was associated with a lower risk of PC (pooled relative effect estimates per one-unit increase within the respective scoring system = 0.96, 95% CI: 0.94–0.97; I 2 = 58.8%). In the categorical analysis, participants in the highest adherence group had a 10% lower risk of PC compared to those in the lowest group (pooled relative effect estimates = 0.90, 95% CI: 0.86–0.94, I 2 = 72.4%). Subgroup analyses: The inverse association was consistently observed in both males and females. Sensitivity analyses indicated that the pooled relative effect estimates remained consistently below 1.0 (ranging from 0.75 to 0.98) after omitting individual studies. Nevertheless, Egger’s test suggested potential publication bias only for the categorical variables, but not for the continuous variables. This meta-analysis suggests an inverse association between higher adherence to the MedDiet and pancreatic cancer risk. However, the observational nature of the available evidence limits causal inference. Further well-designed prospective studies and dietary intervention trials are warranted to confirm this association and clarify its potential implications for pancreatic cancer prevention. https://www.crd.york.ac.uk/prospero/ , identifier CRD420261459967.