The human race is genetically programmed to consume less than 1 g of salt per day. In most human populations, the diet contains 6 to 12 g of salt per day and, in contrast to populations that consume less than 3 g of salt per day, their blood pressure rises with age. Independent of the rise in blood pressure, a high-salt diet also increases left ventricular mass, incidence of strokes, stiffness of conduit arteries, and activity of resistance arteries. In populations with high salt intake, a modest reduction in salt intake lowers blood pressure and diminishes cardiovascular disease and mortality.