The correlation between diet and different pathologies
The SUN Cohort Study
The Seguimiento Universidad de Navarra (SUN) project of the University of Navarra in Spain has been studying the effect of the diet on hypertension, diabetes, obesity, coronary heart disease and other pathologies. The study is still in progress; recruitment originally began in 1999 and until now approximately 15,500 participants have been enrolled. The results gathered until now indicate that:
- There is an inverse association between olive oil or between adhesion to a Mediterranean diet and myocardial infarction;
- With regard In particular to males, there is a reduced risk of hypertension after following a Mediterranean diet rich in olive oil for 28.5 months;
- Data regarding approximately 14,000 subjects showed that those adhering to a strict Mediterranean diet present a reduced risk of developing diabetes;
- In a total population of more than 13,600 subjects, a lower risk of developing cardiovascular disease was found in those adhering to a Mediterranean type diet;
- Some vitamins that are consistently present in the Mediterranean diet are inversely associated to depression.
The results of the SUN study indicate that the higher quality of fats characterizing the Mediterranean diet may be the cause of these beneficial effects.
The ATTICA study
The ATTICA study is a health and nutrition survey that was carried out between 2001 and 2002 on 3024 prevalently male individuals between 20 and 89 living in the province of Attica (Greece). Individuals who did not present signs at the time of enlistment of cardiovascular disease or chronic viral infections were enrolled. A score, called the MedDietScore, was assigned to each participant at the time of enrollment depending on their level of adherence to the traditional Mediterranean diet pattern. The ATTICA study demonstrated that a greater adherence to the Mediterranean diet reduces the risk of left ventricular systolic dysfunction in patients affected with acute coronary syndrome.
The mechanism by which the diet reduces cardiovascular disease is not completely understood. It has been hypothesized, also in the light of the ATTICA study, that the Mediterranean lifestyle contributes to normalizing plasma levels of total cholesterol and of low density lipoproteins (LDL). The Mediterranean diet also contributes to controlling other cardiovascular risk factors such as:
- Insulin resistance;
- Endothelial dysfunction;
- Platelet aggregation;
- Oxidative stress;
- Chronic inflammation.
It is thought that an improvement in the lipid profile is linked to the anti-oxidative activity of the polyphenols in red wine, which would lead to an improvement in the coagulation system and in the level of fibrinolytic activity, in platelet aggregation, and in endothelial function. In synthesis, following a complicated process the vasodilator effect of the polyphenols present in wine translates into an improvement in cardiovascular risk. Anti-oxidant effects and the capacity to reduce LDL levels are also linked to oleic acid, phenolic compounds, and vitamin E present in olive oil. At the same time, polyunsaturated fatty acids and omega-3 fatty acids are able to reduce plasma triglycerides and cardiovascular risk and mortality through an antiarrhythmic effect.