The association between olive oil consumption and primary prevention of cardiovascular diseases

INTRODUCTION: American Heart Association and many other recommend Mediterranean diet for patients with cardiovascular risk. This systematic review and meta-analysis are conducted to review the effects of Mediterranean diet on the cardiovascular events as reported in randomized controlled trials (RCTs). METHODS: A systematic research is conducted on MEDLINE via Ovid, Embase, PubMed, Google Scholar, Web of Science, and Informit. Databases of studies conducted between 2000 and 2017 were included in the analysis. All the collected studies were screened, and at the end, seven RCTs met the inclusion criteria. All the characteristics of trails such as study design, interventions, follow-up duration, and primary and secondary outcomes were recorded. RevMan was used to evaluate risk reduction in each trial individual using forest plot and fixed effects. RESULTS: Four studies were included in the review, having a total of 25,195 participants. The effects of Mediterranean diet were found in cardiovascular events (627), coronary events (251), and all-cause death (887). The analysis revealed that there is a statistically significant relationship between Mediterranean diet and reduction in cardiovascular events at P = 0.02. However, other parameters did not show any statistically significant results that need further investigation. CONCLUSION: The individual RCT provides evidence of protective effects of the Mediterranean diet on cardiovascular events. However, the quality and quantity of data available in those trails are not reliable and limited. Therefore, the results of those trails must be cautiously interpreted.