Revisiting Diet and Appendicitis: A Systematic Review and Meta-Analysis

Area of Science:

• Gastroenterology
• Epidemiology
• Nutritional Science

Background:

• The exact causes of acute appendicitis (AA) remain unknown.
• Western dietary patterns (WDP), characterized by low fiber intake, are suspected to elevate AA risk, but evidence requires quantification.

Purpose of the Study:

• To systematically review and quantify the association between dietary factors and acute appendicitis risk.
• To assess the impact of Western dietary patterns on AA incidence.

Main Methods:

• A systematic review adhering to PRISMA guidelines was performed, searching multiple databases (CENTRAL, MEDLINE, Embase, Scopus).
• Included human studies (case-control, cohort, ecological) published up to December 2024.
• Risk of bias was evaluated using the ROBINS-E tool; data were synthesized narratively or via meta-analysis/regression where possible.

Main Results:

• Twenty-one studies were included, most with high risk of bias.
• Meta-analysis of four case-control studies indicated lower fiber intake in AA patients (p=0.11).
• Meta-regression suggested a trend towards lower population incidence with higher fiber intake; narrative synthesis linked low-fiber, high-meat, or sugar-dense WDPs to increased AA risk.

Conclusions:

• Observational evidence suggests an inverse association between dietary fiber and AA.
• Meat- and sugar-rich Western dietary patterns may increase AA risk.
• Significant uncertainty, heterogeneity, and low-quality data characterize the current evidence base.