Approaches for chronic disease prevention based on current understanding of underlying mechanisms.

Much progress has been achieved by exploring the causes of the main human cancers and of cardiovascular and cerebrovascular diseases. Even more important has been the knowledge acquired about the mechanisms underlying the development of these diseases. In many parts of the world, particularly in the West, the major cancers associated with dietary habits involve the postmenopausal breast, distal colon, prostate, pancreas, ovary, and endometrium. Current evidence suggests that the genotoxic carcinogens for all but the last 2 of these diseases stem from the traditional intake of fried and broiled foods such as meats. The surface of these foods contains a class of powerful mutagens, heterocyclic amines, which are carcinogenic to the target organs in animal models. Fish-eating populations have lower incidences of heart disease and of many types of cancers than do other populations, which may be the result of the n-3 polyunsaturated oils found in fish. Among other dietary practices that may reduce the risk of cancer and cardiovascular disease are consuming 5-9 servings of fruits and vegetables daily, which provides antioxidants such as quercetin and isothiocyanates; having a high fiber intake, including bran cereal; and drinking 1.5-2.5 L of fluids daily. Tea polyphenols found in black and green tea may have a protective effect against heart disease and some cancers. Concentrates of such desirable products have been made available in pill form to complement health-promoting personal lifestyles. Biomedical research funded by The National Institutes of Health and organizations such as the American Cancer Society has produced sound results that could lead to prevention of chronic disease. The public must heed this information to achieve long-term health.