Diet and Disease

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7. Sodium and hypertension

Sodium is a mineral that helps the body regulate blood pressure. It also plays a role in the proper functioning of cell membranes, muscles, and nerves. Sodium concentration in the body is controlled by the kidneys, adrenal glands, pituitary gland, and other glands.

The balance between dietary intake and renal (kidney) excretion through urine determines the amount of sodium in the body. Only a small amount of sodium is lost through the stool or sweat. This balance is maintained primarily by the steroid hormone aldosterone, which controls the amount of sodium in urine. Water and sodium are also related. Retention of more sodium is followed by retention of more fluid, and vice versa.

Sodium-sensitive individuals may experience high blood pressure from excess amounts of sodium in the diet. The American Heart Association has developed specific guidelines for sodium intake. Dietary changes may be beneficial. Sodium intake may have little effect in persons without high blood pressure, but it may have a profound effect in sodium-sensitive individuals.