Even if you don't have high blood pressure, you might want to cut back on the amount of salt in your diet, according to the results of a study published today in the New England Journal of Medicine. Researchers have long debated the merits of a low sodium diet as a means of treating or preventing hypertension, but the authors of the new report indicate that their findings have eliminated the uncertainty. Following the so-called DASH diet, which is rich in fruits and vegetables and low in fat, also substantially reduced blood pressure, even when salt intake was maintained.

In a study supported by the National Heart, Lung and Blood Institute (NHLBI), which has long espoused reducing dietary sodium, 412 participants were randomly assigned to follow either the typical American diet or the Dietary Approaches to Stop Hypertension (DASH) diet. For the first four weeks they consumed 3,300 milligrams of salt each day, which is what Americans typically eat. Over the next four weeks they cut back to 2,400 mg a day (the current recommended maximum). For the last four-week period, the study subjects reduced their daily salt intake to 1,500 milligrams (roughly two thirds of a teaspoon of salt). About 41 percent of these volunteers had high blood pressure, which is defined as blood pressure over 140/90 mm Hg. Following the DASH diet at the lowest sodium level lowered their systolic blood pressure by 11.5 mm Hg on average. Participants in this regimen who had normal blood pressure lowered their systolic pressure 7.1 mm Hg on average.

"The combination of eating the DASH diet at a lower sodium level has a significant effectequal to or greater than the result you would expect from treatment with a single hypertension medication," says Frank Sacks, chair of the DASH-Sodium study Steering Committee. "However, the long-term health benefits of the low sodium DASH diet will depend on whether the American public is willing to make long-lasting dietary changes, including choosing lower sodium foods, and whether the food industry makes available a greater number of low sodium food products."