Experimental Outcomes of the Mediterranean Diet: Lessons Learned from the Predimed Randomized Controlled Trial

Abstract

The Mediterranean Diet (MD) is, culturally and historically, the nutritional pattern shared by people living in the olive-tree growing areas of the Mediterranean basin. It is of great importance for its potential preventive effect against cardiovascular diseases (CVDs). The PREvención con DIeta MEDiterránea (PREDIMED) study, a Spanish multicentre randomised controlled trial (RCT), was designed to assess the long-term effects of the MD, without any energy restriction, on the incidence of CVD in individuals at high cardiovascular (CV) risk. Since its inception, it gave a great contribution to the available literature on the issue. It is well known that, in the field of the health sciences, RCTs provide the best scientific evidence. Thus, the aim of the present review is to analyse the results of the RCTs performed within the frame of the PREDIMED study. Our findings showed that MD has beneficial effects in the primary prevention of CVDs, diabetes and in the management of metabolic syndrome.

Keywords: Mediterranean diet; PREDIMED; cardiovascular disease; dietary intervention; metabolic syndrome; randomized controlled trials; type-2 diabetes mellitus.

Figure 1

Flow chart of the studies’ selection process.

Figure 2

Percentage reduction in the risk of different medical conditions in the PREDIMED Study, according to the group of treatment (MD + EVOO or MD + Nuts) versus the low-fat control diet. The % of risk reduction were computed as: 100 × (1–HR)% and it represents the reduction in the instantaneous risk of the above mentioned events at any given point of time, or the reduction in the rate of such events. ns: not significant. MD: Mediterranean Diet; EVOO: Extra Virgin Olive Oil.