The Effect of Mediterranean Diet on Metabolic Syndrome and Its Components: A Meta-Analysis of 50 Studies and 534,906 Individuals

Study Questions:

Does a Mediterranean diet affect components of the metabolic syndrome?


This study was a systematic review and random-effects meta-analysis of eligible studies identified from PubMed, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials through April 30, 2010. Exclusion criteria were lack of randomization, lack of a control group, not including all components of the metabolic syndrome, or study not published in English. Of the 474 studies identified, 50 original research studies (35 clinical trials, 2 prospective and 13 cross-sectional), with 534,906 participants, were included in the analysis.


Adherence to the Mediterranean diet was associated with reduced risk of metabolic syndrome (log hazard ratio, -0.69; 95% CI, -1.24 to -1.16). Among clinical studies, the Mediterranean diet was protective for components of the metabolic syndrome including waist circumference (-0.42 cm; 95% confidence interval [CI], -0.82 to -0.02), high-density lipoprotein cholesterol (1.17 mg/dl; 95% CI, 0.38-1.96), triglycerides (-6.14 mg/dl; 95% CI, -10.35 to -1.93), systolic (-2.35 mm Hg; 95% CI, -3.51 to -1.18) and diastolic blood pressure (-1.58 mm Hg; 95% CI, -2.02 to -1.13), and glucose (-3.89 mg/dl; 95% CI, -5.84 to -1.95). Data from the epidemiological studies included confirmed these observations.


The authors concluded that adoption of the Mediterranean diet could have significant public health implications given their observations of its effects on components of the metabolic syndrome.


The results of this meta-analysis highlight the importance of diet for prevention of metabolic syndrome. Given the risk for cardiovascular disease and diabetes mellitus associated with metabolic syndrome, clinicians may wish to recommend this type of diet for patients with components of the metabolic syndrome.

Clinical Topics: Diabetes and Cardiometabolic Disease, Dyslipidemia, Prevention, Hypertriglyceridemia, Lipid Metabolism, Nonstatins, Diet

Keywords: Metabolic Syndrome X, Cholesterol, Waist Circumference, Public Health, Blood Pressure, Triglycerides, Diet, Mediterranean, Glucose

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