This study aimed to evaluate the methodological quality of existing meta-analyses (MAs) and the quality of evidence for outcome indicators to in order to provide an updated overview of the evidence concerning the therapeutic efficacy of the Mediterranean diet (MD) for various types of Cardiovascular diseases (CVD).

We conducted comprehensive searches of PubMed, Cochrane Library, and Embase databases. The quality of the MAs was assessed using the A Measurement Tool to Assess Systematic Reviews 2(AMSTAR 2) checklist, while the Grading of Recommendations Assessment, Development and Evaluation (GRADE) evidence evaluation system was employed to evaluate the quality of evidence for significant outcomes.

The burden of CVD remains a significant contributor to global mortality, garnering widespread attention. Multiple MAs have consistently demonstrated the efficacy of medical interventions in managing CVD. However, due to variations in the scope, quality, and outcomes of these reviews, definitive conclusions are yet to be established.

This study included a total of eleven studies, consisting of five randomized trials and twelve nonrandomized studies, with a combined participant population of 716,318.

The eligible MAs underwent evaluation using the AMSTAR 2 checklist, which revealed that 54.55% of the studies demonstrated high quality, while 9.09% exhibited low quality and 36.36% were deemed critically low quality. Additionally, there was moderate evidence supporting a positive correlation between MD and coronary heart disease/acute myocardial infarction (CHD/AMI), stroke, heart failure, cardiovascular events, coronary events, and major adverse cardiovascular events (MACE).

This study indicates that although recognizing the potential efficacy of MD in managing CVD, the quality of the methodology and the evidence for the outcome indicators remain unsatisfactory. To establish the true benefits of MD for CVD patients, future research should not only adhere to rigorous methodological requirements but also prioritize enhancing the quality of primary studies and conducting patient-centered meta-analyses.