Too much salt is bad. Eating a daily banana — or sweet potato — might be a good idea. But when it comes to controlling your blood pressure through diet, it's best to think bigger, experts say.
Your whole diet, not any miracle food or salt reduction alone, is the key to getting those numbers down and potentially lowering your risk for stroke, heart attack, kidney damage and other diseases. The right diet also might help keep you off medication or lower your doses, according to the American Heart Association.
That's a message that's been lost amid recent scientific arguments about the ideal amount of salt for Americans to eat, says Lawrence Appel, director of the Welch Center for Prevention, Epidemiology and Clinical Research at Johns Hopkins, Baltimore. Appel, who also is a spokesperson for the heart association, is, however, in the camp that says salt is a major contributor to high blood pressure and to disease and death. Studies that fail to show a direct link between high-salt diets, disease and death have been flawed but widely publicized, he says: "That's really unfortunate."
Strong studies do show that dietary habits, including sodium intake, have a significant effect on blood pressure itself. Diets that emphasize fruits, vegetables, whole grains, low-fat dairy, poultry, fish and nuts while minimizing red meat and sugars are best, the heart association says. That pretty much describes DASH (Dietary Approaches to Stop Hypertension) — the best-studied diet for controlling blood pressure.The diet was developed in studies sponsored by the National Heart, Lung and Blood Institute.
At the heart of the DASH diet are specific targets for key food groups — including 3-6 daily servings of vegetables and 3-6 daily servings of fruit, depending on calorie needs.
In studies, people who ate the DASH diet without cutting sodium achieved lower blood pressures than those who ate typical American diets. Those who combined DASH with reducing sodium, to 2,300 mg. per day, did even better; those who cut sodium to 1,500 mg, did best. The typical American consumes about 3,600 mg.
The key to success may be the balance of minerals — the subtracted sodium and the added potassium, calcium and magnesium, says Appel, a lead DASH researcher. Potassium looks especially important, he says.
"Higher levels of potassium blunt the effects of sodium. If you can't reduce or won't reduce sodium, adding potassium may help," he says. "But doing both is better."
Potassium is plentiful in many fruits (cantaloupes and oranges, as well as bananas) and vegetables (from potatoes to spinach), but also in fish, nuts and dairy foods.
The Food and Drug Administration recognized potassium as a blood pressure reducer when it proposed new food labels this year: It added the mineral to the required list on labels. The typical American eats 2,600 mg. of potassium a day, well below the recommended 4,700 mg.