Epidemiologic studies and clinical trials have shown that diet and, in particular, the consumption of
fats, influence the body's metabolism and can affect the development of
atherosclerosis and resulting cardiovascular repercussions. A Western-type diet (high in saturated
fats,
simple sugars and
salt, and low in fish, vegetables and fiber) has been associated with proinflammatory, pro-oxidative and prothrombotic tendencies and consequently higher cardiovascular risk. By contrast, a Mediterranean-type diet (with less meat and more fish, fiber, fruit, vegetables,
olive oil and wine) appears to explain the lower tendency for
cardiovascular disease (and
cancer) in those who consume it. Between these two are population groups who prefer diets rich in
polyunsaturated fatty acids. The lack of randomized and rigorously controlled population and clinical trials relating types of diet to primary or secondary cardiovascular events may explain some of the disagreements surrounding this subject. It would also explain the lack of results that shed light on diet-dependent mechanisms that may affect the development of
atherosclerosis. In general, it is accepted that the morphologic and functional characteristics of vascular endothelium are influenced by the components absorbed from the diet. Prolonged exposure to certain harmful components in the diet may increase the risk of endothelial dysfunction, as shown by a decrease in antithrombotic, antioxidative, antiinflammatory and peripheral vasodilatory modulators, which represents the first step towards the onset of
atherosclerosis. Among the main mechanisms involved in endothelial dysfunction are the proinflammatory and prooxidative effects of excess
cholesterol, in contrast with the apparent benefit of
monounsaturated fatty acids and the less consistent results obtained with
polyunsaturated fatty acids.