Transferability of the Mediterranean Diet to Non-Mediterranean Countries. What Is and What Is Not the Mediterranean Diet

Substantial evidence has verified the Mediterranean diet’s (MedDiet) nutritional adequacy, long-term sustainability, and effectiveness for preventing hard clinical events from cardiovascular disease (CVD), as well as increasing longevity. This article includes a cumulative meta-analysis of prospective studies supporting a strong inverse association between closer adherence to the MedDiet and the incidence of hard clinical events of CVD. The MedDiet has become an increasingly popular topic of interest when focusing on overall food patterns rather than single nutrient intake, not only in Mediterranean countries, but also globally. However, several myths and misconceptions associated with the traditional Mediterranean diet should be clearly addressed and dispelled, particularly those that label as “Mediterranean” an eating pattern that is not in line with the traditional Mediterranean diet. The transferability of the traditional MedDiet to the non-Mediterranean populations is possible, but it requires a multitude of changes in dietary habits. New approaches for promoting healthy dietary behavior consistent with the MedDiet will offer healthful, sustainable, and practical strategies at all levels of public health. The following article presents practical resources and knowledge necessary for accomplishing these changes.

In the experimental group the adjusted RR of CV deaths and of total major primary endpoints were 0.24 (95%CI: 0.07-0.85) and 0.27 (95%CI: 0.12-0.59) respectively Trichopoulou, 2003 Greek pattern has been widely recommended for the prevention of the chronic disease.
Several observational studies and a few clinical trials have examined the association between this food pattern and different health outcomes. However, the evidence on the prevention of cardiovascular disease by MedDiet deserves to be systematically reviewed.
The purpose of this cumulative meta-analysis is to quantify the association between the adherence to the MedDiet and risk of mortality from or incidence of cardiovascular disease and to assess the consistency of previous observational findings with those of randomised controlled trials (RCT).

SEARCH STRATEGY AND STUDY SELECTION
We will conduct electronic searches in PubMed, Embase, Google Scholar and Web of Science.
Search terms: "Mediterranean diet" in combination with keywords relating to cardiovascular events ("cardiovascular disease", or "cerebrovascular", or "ischemic", or "stroke", or "coronary"). We also will review the bibliographies of the extracted articles and reviews to locate additional publications.
The parameters of search strategy will include the following filters: language (English, Spanish, Italian, French), age (up to 18 years old) and human studies. No time period limit will be established. Originals published up until May 2017 will be included in this search.

Inclusion criteria
• Clinical trials or prospective cohort studies with appropriate control of confounding, originals and primary prevention of mortality or incidence of cardiovascular disease through MedDiet.
• The exposure of interest was the adherence to the MedDiet • The outcome was mortality from cardiovascular disease or incidence of cardiovascular events (coronary heart disease or stroke) Exclusion criteria

DATA EXTRACTION
Two independent reviewers initially will conduct the search strategy on primary titles and abstracts to select potential articles. Next, one of the reviewers will assess in detail the selected full-text article and will decide their eligibility according to the inclusion/exclusion criteria and will extract the data of interest for the cumulative meta-analysis after discussion and consensus.
Study details: authors, study design, sample size and sample characteristics, dietary assessment method, average duration of follow-up, number of non-fatal and fatal events and results and covariates in fully adjusted model.

Analyses plan
• Relative risks and 95% confidence intervals will be considered as the magnitude of association for all studies, and the odds ratios or hazard ratios will be considered equivalent to relative risks.
• Those articles reporting both risk of mortality from or incidence of cardiovascular disease will be treated as two separate reports.
• Because it is possible that different cut-off points for adherence to the MedDiet categories will be present in different articles, we will compute a relative risk with 95% confidence interval for an increase of two points in adherence to the MedDiet score for each report.
• Papers published by the same research group and studying similar factors in the same cohort will be checked for potential duplicate data. When it occurs, the most recent set will be used for meta-analysis, but excluding the incident events or cases of mortality reported in previous research.

Management and Coordination
• MAM-G will develop the initial plan, study design, and will be responsible for data collection, data extraction, and data initial interpretation.
• MAM-G will be responsible for statistical analysis.
• MAM-G and IZ will be responsible for data interpretation, critical revision of intellectual content, and approval of the version to be published.