Mediterranean diet in the primary prevention of cardiovascular disease

Sandra Helinski

Ramón Estruch1,2, Rosa Casas1,2, Paola Quifer-Rada2,3, Rosa María Lamuela-Raventós 2,3
1Internal Medicine Department, Hospital Clinic, IDIBAPS, University of Barcelona, Barcelona, Spain.
2CiBER OBN, Instituto de Salud Carlos III, Gobierno de España.
3Department of Nutrition, Food Science and Gastronomy, XaRTA, INSA-UB, School of Pharmacy and Food Science, University of Barcelona, Barcelona, Spain

The Mediterranean diet (MeDiet) is characterized by abundant use of olive oil; high consumption of fruits, vegetables, legumes, cereals, nuts and seeds; moderate intake of wine with meals; moderate consumption of fish, seafood, fermented dairy products, poultry and eggs; and low consumption of red and processed meat and sweets. Several epidemiological studies have pointed out that high adherence to MeDiet is associated with strong protection against cardiovascular disease (CVD). However, the highest level of scientific evidence only is obtained by the performance of randomized clinical trials. The PREDIMED (PREvención con DIeta MEDiterránea) study assessed the long-term effects of the MeDiet on incident CVD. After 4.8 years, 288 major CVD events occurred in 7447 participants. Those who followed-up a MeDiet+Extra Virgin Olive Oil (EVOO) and MeDiet+nuts showed a 30% reduction in the incidence of CVD compared to the control group. Incident diabetes (273 cases) among 3541 non-diabetic participants diminished by 40% in the MeDiet+EVOO compared to the control group.
In addition, the PREDIMED trial have demonstrated with the highest level of scientific evidence that an increased adherence to traditional Mediterranean diet is associated with improved cognitive function. When the role of the different foods included in the Mediterranean diet was analyzed, we observed that the participants with better cognitive function were those with higher consumption of wine, extra-virgin olive oil, coffee and walnuts, all foods very rich in polyphenols.
Analyses of intermediate markers of cardiovascular risk demonstrated beneficial effects of the MeDiets on blood pressure, lipid profiles, lipoprotein particles, inflammation, oxidative stress, and carotid atherosclerosis. Finally, recently we have observed significant reductions of cellular and endothelial inflammatory markers related to atherosclerosis at 3 and 5 years in the MeDiet+EVOO and MeDiet+Nuts groups. Thus, long-term adherence to the MeDiet improves cardiovascular risk factors and modulates inflammatory responses in the arterial wall. These results help to explain in part the cardioprotective effect of the MeDiet.
In conclusion, the PREDIMED results demonstrate that a high-unsaturated fat and antioxidant-rich dietary pattern such as the MeDiet is a useful tool in the prevention of cardiovascular disease.