The new findings strengthen the case for heavy salt intake as a stroke risk factor, according to Dr. Francesco P. Cappuccio, of the University of Warwick in the UK, who wrote an editorial published with the study in the journal Stroke.

It's well-known that as people's sodium intake goes up, their blood pressure is likely to increase as well.

It's been less clear, though, whether a salty diet may ultimately mean higher risks of heart attack and stroke down the road.

Unlike blood pressure, which changes quickly, stroke and heart disease are long-range complications. So studying the relationship between people's sodium intake and their risk of heart problems and stroke is more difficult.

Right now, the AHA suggests that people limit their sodium intake to no more than 1,500 milligrams a day. That's a bit more strict than some other recommendations; the World Health Organization, for example, advises a limit of 2,000 milligrams.

But people in the current study typically consumed well above those recommendations. They averaged 3,031 milligrams of sodium per day.

The findings are based on 2,657 adults who were interviewed about their health and lifestyle, and completed dietary questionnaires. They were 69 years old, on average, at the study's start.

Over the next 10 years, there were 235 strokes in the group. And people who'd downed at least 4,000 milligrams of sodium each day at the outset were almost three times more likely to suffer a stroke as those who'd kept their daily sodium below 1,500 milligrams.

Among the 558 people whose sodium intake topped 4,000 milligrams per day, there were 66 strokes.

That compared with 24 strokes among the 320 people who met the AHA guideline.