Vegetables and fruits oN the Mediterranean Diet

Consumption of vegetables and fruits has been systematically found to reduce the risk of most forms of cancer, although the responsible compounds or processes have not yet been established. High consumption of vegetables and fruits is typical among Mediterraneans and helps explain the relatively low incidence of several forms of cancer in the region. Some of the earliest studies demonstrating this inverse association have been reported from Mediterranean countries, particularly from Greece, where the consumption of vegetables has been and remains exceptionally high. Thus, in 1983, it was reported that high consumption of vegetables and, independently, low consumption of red meat substantially reduce the risk for cancer of the large bowel. Two years later, the results of another study indicated that individuals consuming high quantities of raw vegetables and citrus fruits, as well as whole-grain bread, were less likely to be affected by cancer of the stomach. Another study from Greece21 was the first to point out that consumption of vegetables was inversely associated with breast cancer risk, an association that was later confirmed by several researchers. The connection was also noticed in a larger investigation in Greece.A protective effect of vegetables and fruits against cancer of various sites
has been documented in a number of epidemiological studies in the Greek population.
An effect of fruits was more evident with respect to lung cancer,whereas crude fiber, mostly from vegetables, was the discriminatory protective agent in studies of ovarian and pancreatic cancers.Fruits and vegetables were also the only food groups inversely associated with cancer of the endometrium and adenocarcinoma of the esophagus, although these associations were not always significant. It should be pointed out that, in most of the previously mentioned studies,
the associations with particular micronutrients, including ß-carotene and vitamin C, were generally not as strong as those with vegetables and fruits as a whole. The protective effect of vegetables and fruits against malignancies of various sites has also been documented in a series of case-control studies conducted in Italy. The results of these studies are summarized in a review by La Vecchia and Tavani,who point out that the association is generally most marked for epithelial cancers, apparently stronger for those of the digestive and respiratory tracts, and somewhat weaker for hormone-related cancers. Studies conducted in other parts of the world have also supported a protective role of fruits and vegetables against different forms of cancer.
In fact, such associations represent the main thrust of nutritional epidemiology of cancer.
With respect to cardiovascular diseases, studies in Greece have also provided evidence that high intake of total carbohydrates and crude fiber, reflecting a high intake of vegetables and fruits, is beneficial against atherosclerosis, as manifested in peripheral arterial occlusive disease and CHD.These findings have been supported by the results of other large and sophisticated investigations, and are compatible with a generalized beneficial effect of a diet rich in antioxidant substances.
They could, however, also be explained in terms of the homocysteine hypothesis. Recently, accumulated evidence on the deleterious role of plasma homocysteine levels on CHD risk, provides solid biologic foundation for the inverse association between consumption of vegetables on the one hand, and CHD and peripheral arterial disease on the other, as homocysteine levels are reduced by folic acid, which is found mainly in vegetables.