The Influence of Dietary Sodium on Blood Pressure

The goal of this essay is to examine the evidence relating salt intake to blood pressure in humans. Despite studies involving many thousands of subjects and patients performed in many hundreds of centers the issue remains controversial-indeed far more controversial than seems appropriate. There is little disagreement that in some animal models and in some patients with hypertension salt intake can exert a rather substantial influence. There is more controversy on the responsible mechanisms. The greatest controversy, by far, involves whether or not policy should involve a mandatory reduction in salt intake in all members of the community. The available evidence shows that the influence of salt intake is too inconsistent and generally too small to mandate policy decisions at the community level. At the level of the individual patient and that patient's physician, it is important to recognize that salt intake can make a substantial contribution to hypertension. That contribution is more likely if the patient is old rather than young, obese rather than lean, black rather than white, has diabetes mellitus with hypertension, or has evidence of renal injury. Unfortunately, tools for assessing the sodium and chloride intake in the individual and for assessing its contribution to BP in the individual are inadequate. On the bright side, prognosis is improved substantially by the array of antihypertensive drugs available today.