European Mediterranean populations have a high life expectancy. Several aspects of their diet are considered favorable on health. We considered the role of various aspects of the
Mediterranean diet on
cancer risk in a series of Italian case-control studies including about 10,000 cases of
cancer at 13 different sites and over 17,000 controls. For most epithelial
cancers, the risk decreased with increasing vegetable consumption. Allium vegetables were also favorably related to
cancer risk. Fruit intake was inversely associated with digestive tract and
laryngeal cancers. For digestive tract
cancers, the population attributable risks for low intake of vegetables and fruit ranged between 15% and 40%.
Olive oil and
unsaturated fats, which are typical aspects of the
Mediterranean diet, were inversely related to the risk of several
cancers, particularly of the upper aerodigestive tract. Whole grain food (and hence possibly fiber) intake was also related to reduced risk of various
cancers. In contrast, refined grains and, consequently, glycemic load and index were associated to increased risks. Several
micronutrients and food components (including
folate,
flavonoids, and
carotenoids) showed inverse relations with
cancer risk, but the main component(s) responsible for the favorable effect of a diet rich in vegetables and fruit remain undefined.