Dietary Electrolytes and Blood Pressure

Abstract

B lood pressure–associated risks ensue incrementally over a wide range of blood pressure levels, and even among nonhypertensive persons, blood pressure levels are predictive of morbidity and mortality from stroke, heart disease, and end-stage renal disease.1–3 On a population basis, it has been estimated that a reduction in diastolic blood pressure of 2 mm Hg would result in a 15% reduction in risk of stroke and transient ischemic attacks and a 6% reduction in risk of coronary heart disease.4 Between 1971 and 1991, national health examination surveys5 documented a downward trend in blood pressure levels and the prevalence of hypertension in the United States. Adoption of a healthier lifestyle may have contributed to this favorable trend. Not all subgroups have benefited equally, however, particularly African Americans. According to the Third National Health and Nutrition Examination Survey (NHANES III)6 (1988 to 1991), 24% of the US population was classified as having hypertension. Blood pressure level and hypertension prevalence increase with age: high-normal and high blood pressure continue to be major contributors to cardiovascular disease.7 The relationship between dietary electrolyte consumption and blood pressure is the focus of this brief review. Evidence for a positive association between sodium chloride (NaCl) intake and blood pressure is discussed. Increasing evidence also suggests that dietary patterns associated with low intakes of potassium, calcium, and possibly magnesium also contrib- ute to higher levels of blood pressure. An understanding of these associations has important implications not only for the prevention and treatment of hypertension but also for devel- oping population-based strategies to decrease cardiovascular disease risk by shifting the overall blood pressure distribution toward lower levels.