Americans Advised to Shake the Salt Habit

      For years, scientists have been arguing over whether to recommend to all patients - even those without hypertension - that they reduce salt intake in their diets.

      The National Institutes of Health hopes to unambiguously end the debate today when it makes public research that suggests that lowering blood pressure is good for everyone.

      Unlike earlier research, this study made a concerted effort to broaden its reach, cutting across racial and risk categories.

      The study, whose results will be presented at a meeting of the American Society of Hypertension in New York, looked at the effects of salt on blood pressure among a diverse group of Americans: men, women, young, old, white, black and those with and without hypertension. Researchers also looked at the salt factor in combination with two different kinds of diets, one healthful and the other not so healthful.

      "The effects were quite substantial, even if you don''t have high blood pressure," said Dr. Eva Obarzanek, one of the lead researchers.

      "This finding should answer the question," said Dr. Claude Lenfant, director of the institutes'' Lung and Blood Institute, which sponsored the study.

      In recent years, some researchers have questioned blanket recommendations that everyone could benefit by lowering salt intake, arguing that it would have no effect on those who do not have hypertension and that it might be dangerous.

      Dr. Michael Alderman, former president of the Hypertension Society and one of the most vocal critics of the edict that all patients should lower salt intake, was not convinced otherwise by the new research.

      "If lowering blood pressure a little bit could be done at no cost, that would be a wonderful thing, but I''m not sure that is the case," said Alderman, a professor of medicine and epidemiology at Albert Einstein College of Medicine in New York City.

      Alderman said reducing salt can cause irregularities in heart rhythm and cardiac cell growth and can interfere with the body''s response to insulin.

      Furthermore, he argued, it has not been demonstrated that lower blood pressure actually ends up producing fewer heart attacks and strokes and a longer life span.

      "The low sodium argument is a very rational argument," he said, "but I''d like to see if people are really better off as a result."

      Obarzanek, a nutritionist at the institutes, said that no study has found "any adverse effects of moderate reduction in sodium" and that the link between high blood pressure and increased risk of stroke and heart attack is not in dispute.

      "We know that lowering sodium lowers blood pressure," she said. "Why wouldn''t you make the leap?"

      About 50 million adult Americans suffer from hypertension, and only about 68 percent of them are aware of it. Hypertension is a known risk factor for heart and kidney disease and stroke, and many researchers are convinced that lowering blood pressure will stave off those life-threatening conditions.

      The study found that reducing salt resulted in lower blood pressure for all individuals regardless of diet. And the lower the salt, the lower the readings.

      Americans typically consume about 4,000 to 6,000 milligrams of salt a day - two to three teaspoons.

      Current recommendations urge that salt consumption be kept to a maximum of 2,400 milligrams. Obarzanek said the findings may prompt health officials to further lower the recommended amounts, perhaps to 1,500 milligrams.

      The study looked at 412 people, age 22 or older, randomly assigned to one of two dietary plans, each containing one of three different levels of sodium, ranging from a high of 3,300 milligrams per day to an intermediate level of 2,400 milligrams to the lowest intake of 1,500 milligrams.

      Members of each group consumed different levels of sodium at different stages of the trial, which lasted 14 weeks.

      The two diets were a typical, high-fat American diet that includeda lot of processed and snack foods and the so-called DASH diet, which is low in saturated fats and cholesterol and high in fruits, vegetables, low-fat dairy products, whole grains, poultry, fish and nuts. The DASH diet contains little red meat and sugar.