Mediterranean diet improves low density lipoprotein susceptibility to oxidative modifications

BACKGROUND: Most experts, specially from Anglo-Saxon countries, recommend a low fat diet in order to prevent cardiovascular diseases. However, mortali ty rate by ischemic cardiopathy is low in Mediterranean diet, with a high l evel of monounsaturated fats provided by the olive oil. We have conducted t his study in order to investigate the possible influence of this kind of di et on the oxidation of LDL in vitro, the key element for the development of atherosclerosis. PATIENTS AND METHODS: 41 healthy male subjects were submitted to three cons ecutive 4-week diets. The first was a saturated fat-rich diet (SAT diet, 38 % fat, 20% saturated). This was followed by a low fat diet (NCEP-I, 28% fat , 10% saturated) and after that a Mediterranean diet (38% fat, 22% monounsa turated fat). Plasma levels of total cholesterol, LDL-c, HDL-c, triglycerid es, apolipoproteins A-I and B, alpha -tocopherol, and the in vitro suscepti bility to oxidation of LDL particles. RESULTS: Both hypolipidemic diets produced a significant decrease in total cholesterol, LDL-c, and apo-B plasma levels. However, it was only the NCEP- I diet that revealed a decrease in the HDL-c. The shift from a saturated fa t-rich diet, or a diet rich in carbohydrates, to a Mediterranean diet incre ased the resistance of LDL particles to oxidation increasing the lag time p eriod (p < 0.038), and decreasing (p < 0.001) the progression rate of the c urve of oxidation of LDL. CONCLUSION: Our results point out two positive consequences of the consumpt ion of a Mediterranean diet by healthy young males, compared with the low f at diet recommended by most Anglo-Saxon experts. On the one hand, the Medit erranean diet increases HDL-c plasma levels, and on the other hand, it decr eases the susceptibility of LDL to oxidation. This is why the Mediterranean diet must be recommended in order to prevent cardiovascular diseases.