Association between Mediterranean diet adherence and colorectal cancer: a dose-response meta-analysis

Am J Clin Nutr. 2020 Jun 1;111(6):1214-1225. doi: 10.1093/ajcn/nqaa083.


Background: Mounting epidemiologic studies have investigated the potential inverse association between Mediterranean diet (MD) adherence and colorectal cancer (CRC) incidence and mortality.

Objectives: This meta-analysis aimed to investigate the association between MD adherence and CRC incidence and mortality.

Methods: PubMed, Embase, and Web of Science were searched to identify eligible studies through September 2019. A random-effects model was used to estimate summary RRs and 95% CIs.

Results: This meta-analysis included 13 prospective cohort studies, of which 9 reported CRC incidence and 5 reported CRC mortality. The summary RR of CRC incidence was 0.90 (95% CI: 0.84, 0.96) for highest compared with lowest MD adherence and 0.96 (95% CI: 0.94, 0.99) per 2-score increase in MD adherence. The summary RRs for highest compared with lowest MD adherence were 0.82 for rectal cancer (95% CI: 0.71, 0.95), 0.94 for proximal colon cancer (95% CI: 0.87, 1.02), and 0.91 for distal colon cancer (95% CI: 0.79, 1.04). Neither the summary HR of overall mortality for highest compared with lowest pre- and postdiagnosis MD adherence, nor the summary HR of CRC-specific mortality for highest compared with lowest prediagnosis MD adherence achieved a value with statistical significance.

Conclusions: Our meta-analysis supports the inverse association of MD adherence with CRC incidence, but not with overall mortality or CRC-specific mortality among those diagnosed with CRC.

Keywords: Mediterranean diet; colorectal cancer; dose-response meta-analysis; epidemiology; nutrition.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't
  • Systematic Review

MeSH terms

  • Adult
  • Aged
  • Colorectal Neoplasms / epidemiology
  • Colorectal Neoplasms / metabolism*
  • Colorectal Neoplasms / mortality
  • Colorectal Neoplasms / psychology
  • Diet, Mediterranean / psychology*
  • Diet, Mediterranean / statistics & numerical data
  • Female
  • Humans
  • Incidence
  • Male
  • Middle Aged
  • Patient Compliance / psychology*
  • Patient Compliance / statistics & numerical data
  • Prospective Studies