It is generally accepted that genetics play a significant role in the pathogenesis of hypertension. Since hypertension often follows kidney transplantation, candidate genes have been sought and found in the kidneys of rats and humans. One well-recognized, inherited influence on blood pressure (BP) occurs via abnormal renal sodium handling in vivo. Further, abnormal renal sodium handling is seen in isolated kidneys of genetically hypertensive rats. People who have a relative inability to handle a sodium load properly, and retain it inappropriately, often develop high BP and are referred to as "salt-sensitive". More than half of patients diagnosed with essential hypertension are salt-sensitive. In contrast to the deleterious effects associated with high sodium intake, many believe that ingestion of more potassium, calcium, and magnesium may influence BP favorably. The beneficial effects of these ions work, at least in part, through an effect on sodium balance, i.e. a diuretic influence. In support of this concept, they lower BP more effectively in salt-sensitive hypertensives. Refined carbohydrates and saturated fats are also associated with salt retention and hypertension. Thus, dietary factors, working directly on their own and/or indirectly via effects on genetic mechanisms, may alter BP favorably or unfavorably.