Diet and cancer prevention: A review of Italian studies

Current scientific evidence suggests a protective role for fruits and vegetables in prevention of most common epithelial cancer including digestive and major non-digestive neoplasm. The relation between frequency of consumption of vegetables and fruit and cancer risk was analyzed using data from a series of case-control studies conducted in Northern Italy since 1983. For digestive tract cancer, population attributable risks for low intake of vegetables and fruit ranged between 15 and 40%. A selected number of anti-oxidants showed a significant inverse relation with breast and colorectal cancer risk. Red meat intake confirmed to be of specific relevance in nutritional etiology of human cancer with a relative risk (RR) far consistently above unity. Whole grain food intake was consistently related to reduced risk of several types of cancer, with a particular relevance for the upper digestive tract neoplasm. Epidemiological evidence on the relation between fiber intake and colorectal cancer have reported a moderate protection, but results are limited and inconsistent. Thus, we investigated the specific role of fibers on colorectal carcinogenesis in a case control study including 1,953 cases of colorectal cancer and 4,154 controls. Results provided further support for a protective and independent effect of fiber on colorectal cancer, particularly for cellulose and soluble non-cellulosic polysaccharides (NCP), and for fiber of vegetable or fruit origin. In contrast, refined grain intake has been associated to increased risk of different types of cancer. In conclusion, a low risk diet for cancer would imply increasing fruit and vegetables, avoiding increasing meat, but also refined carbohydrate consumption, and preferring olive oil and other unsaturated fats to saturated ones.