Analysis of 91,000 cardiovascular disease patients across 19 studies reveals that Mediterranean diet adherence reduces major adverse cardiac events by 56% and mortality by 73% in randomized trials, with more modest but significant benefits observed in observational cohorts. The protective effects were consistent across different study designs, suggesting robust evidence for secondary prevention benefits. This finding fundamentally shifts the Mediterranean diet conversation beyond primary prevention into established disease management. While previous research established the diet's role in preventing initial cardiovascular events, demonstrating such substantial mortality benefits in patients who already have heart disease represents a paradigm advancement for clinical practice. The dramatic effect sizes in controlled trials—particularly the 73% mortality reduction—exceed what most pharmaceutical interventions achieve in secondary prevention. However, the mixed certainty of evidence and lack of significant effects on intermediate markers like blood pressure and lipids suggest the protective mechanisms may be more complex than traditional risk factor modification. For the millions living with cardiovascular disease, this evidence supports Mediterranean diet adoption as a cornerstone therapeutic intervention, potentially rivaling medication-based approaches in effectiveness.