Photo: Bally Scanlon/Getty Images

In the 1990s, it was sugar; in the 2000s, trans fats. And the nutritional villain of the current decade? Salt. A new report by the Institute of Medicine suggests that lowering Americans' sodium consumption to 2,300 milligrams a day could save 100,000 lives every year by reducing the risk of high blood pressure.

But whereas sodium drives up blood pressure, another mineral—potassium—brings it down. Research from Loyola University Health System has found that the ratio of sodium to potassium consumption is more important than the intake of either mineral alone. Study author Paul Whelton, MD, found that people with the highest sodium-to-potassium ratio in their urine were 50 percent more likely to develop cardiovascular disease than those with the lowest ratios.

"High potassium levels may act as a diuretic, causing sodium to be excreted," Whelton says. "Or potassium may dilate and relax the muscles in blood vessel walls." The mineral has also been found to reduce the risk of stroke, yet "most Americans get only half their recommended allowance [4,700 milligrams a day]," says Whelton. Particularly rich sources include spinach, tomatoes, dates, beets, beans, cantaloupe, potatoes, and bananas.

NEXT: How much sodium is too much?