Diet is linked to the etiology of about 50% of all cancers, acting as a promoter, in the multi-step pathogenesis of cancer. Research indicates that a high-fat and low-fiber diet increases the risk for some cancers. The aim is to have people eat a low-fat diet of 25% or less of total daily calories and a high-fiber diet of 20-30 gm/daily. Research also indicates that a lack of host resistance increases the risk for cancer, acting as a promoter. Vitamins A, B6, C & E and the minerals selenium and zinc have proved to be safe and since they have shown some evidence of being able to restore or maintain immunocompetence they are recommended as dietary supplements. Exercise, a low-fat and high-fiber diet and avoiding obesity are not only important in reducing cancer incidence and thereby increasing longevity but they are also important in reducing the incidence of cardiovascular disease, i.e., strokes and coronary heart disease. Total cholesterol levels less than 200 mg/dl are desirable, those between 200-239 mg/dl place patients at borderline risk and those 240 mg/dl or higher place them at high risk. Of equal, or even greater importance are the levels of the "bad cholesterol" LDL that produces arteriosclerosis. Levels less than 130 mg/dl are desirable, those between 130-159 place patients at borderline risk and those over 160 mg/dl place them at high risk. The higher the levels are for the "good cholesterol' HDL, then the lower is the risk, with the norms being 30-75 mg/dl.(ABSTRACT TRUNCATED AT 250 WORDS)