The Mediterranean Diet and Plasma Lipid Profile Dieta mediterránea y perfil lipı́dico plasmático

Cardiovascular disease (CVD) continues to be the main cause of morbidity and mortality in the 21st century. As it is almost always more cost-effective to invest in prevention than to cover the treatment costs of most diseases, many governments and institutions consider the prevention of cardiovascular disease to be a main priority of public healthcare systems. This prevention strategy is based on promoting a healthy lifestyle, including healthier diet patterns, more physical activity, body weight control, and cessation of toxic habits like smoking, excessive alcohol consumption, etc. The relationship between diet (nutrition) and CVD has been one of the most active areas of research in nutritional epidemiology over the last 50 years. Many studies have analyzed the effects of the consumption of certain foods and nutrients on different vascular risk factors. Currently, however, the study of the effects of different eating patterns on health is considered a better approach because it assesses the synergic interaction of different foods and nutrients that make up diet. Several studies, including the most recent meta-analyses, indicate that the traditional Mediterranean diet, defined as the dietary pattern of the peoples that lived around the Mediterranean Sea during the 1960s, seems to be the most effective eating pattern for preventing numerous chronic diseases, including CVD. In other words, there is growing scientific evidence to confirm that what is known as the ‘‘Mediterranean paradox’’ (meaning lower absolute risk of ischemic heart disease for the same level of exposure to a risk factor) is due to a protective effect of the diet and lifestyle followed by the inhabitants of the Mediterranean countries. This dietary pattern, known as the Mediterranean diet, is characterized by: an abundant use of olive oil; high consumption of plant-based foods (fruit, vegetables, legumes, grains, nuts, seeds); frequent but moderate wine consumption (especially red) at meals; moderate consumption of fish, seafood, fermented dairy products (yogurt, cheese), poultry, eggs; and limited consumption of red meat, processed meat products, and also sweets. The diet is rich in key nutrients, such as monounsaturated fatty acids (olive oil), polyunsaturated fatty acids (fish, nuts), dietary fiber (grains, vegetables, fruit, legumes), polyphenols (wine, extra virgin olive oil, fruit, vegetables), vitamins (vitamins A, D, E, folic acid, riboflavin, vitamin B12), and minerals (potassium, calcium, phosphorus, magnesium), which could explain the cardiovascular benefits associated with this type of diet. Several epidemiologic and clinical studies have evaluated the effects of this diet on intermediate markers of cardiovascular disease, such as blood pressure, glycemia, plasma cholesterol concentrations and subfractions, plasma inflammatory biomarkers, or other biological markers. While useful, this focus has certain limitations. For instance, there are possibly multiple pathways by which an inappropriate diet could lead to the development of CVD; on the other hand, different dietary components also require varying induction periods for them to take effect, and they could likewise affect different pathways. Furthermore, the results of several epidemiologic studies indicate that global dietary patterns can promote or prevent CVD to a greater degree than the consumption of isolated foods or nutrients. Thus, it is currently believed that the best way to evaluate the influence of the diet on CVD is the analysis of important clinical objectives for morbidity and mortality, which are also known as hard endpoints. Operating on these premises, the PREDIMED study clearly demonstrated the beneficial effect of the Mediterranean diet for the primary prevention of CVD. This study included subjects at high cardiovascular risk but no previous CVD, who had been randomized to receive either a Mediterranean diet supplemented with either extra virgin olive oil or nuts versus a low-fat diet. The primary endpoint of the study was the appearance of the main clinical manifestations of CVD, such as cardiovascular death, nonfatal myocardial infarction, or stroke. Secondary endpoints included total mortality, type 2 diabetes mellitus, metabolic syndrome, peripheral artery disease, atrial fibrillation, neurodegenerative disease, and the main types of cancer. A total of 7447 participants were randomized to 1 of the 3 mentioned intervention groups. Said groups presented similar baseline clinical characteristics and medical treatments. During followup, the participants included in the 2 Mediterranean diet groups quickly and significantly improved their adherence to the traditional Mediterranean diet, and this compliance remained high during the entire trial. After 4.8 years of follow-up, 288 major cardiovascular events were diagnosed: 96 in the Mediterranean diet and olive oil group (3.8%), 83 in the Mediterranean diet and nut group (3.4%), and 109 in the control group (4.5%). These data represent a Rev Esp Cardiol. 2015;68(4):279–281