Cutting back on salt intake from current levels to 2,300 milligrams a day -- the upper end of the federal guideline -- could save 500,000 to 850,000 lives over the next 10 years, according to research published in the journal Hypertension. Even a more gradual reduction in salt content among restaurant and processed foods could save 280,000 to 500,000 lives in 10 years, largely by reducing the risks of heart attack and stroke.