Older adults with salty diets may have an increased risk of suffering a stroke, according to a US study of more than 2,000 people.
Though it is well known that as people's sodium intake rises, their blood pressure is likely to increase as well, it is less clear whether a salty diet may ultimately mean higher risks of stroke and heart attack down the road.
But researchers whose findings were published in the journal Stroke said that of the close to 2,700 older, mostly minority adults they studied, those who got well above the recommended sodium intake were nearly three times as likely to suffer a stroke over 10 years as people who met guidelines recommended by the American Heart Association.
“High sodium intake was prevalent and associated with an increased risk of stroke independent of vascular risk factors,” wrote Hannah Gardener, a researcher at the University of Miami School of Medicine, who led the study.
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.
The American Heart Association (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 organisation, for example, advises a limit of 2,000 milligrams.
But people in the new study, mainly black and Hispanic New Yorkers, typically consumed well above those recommendations, averaging 3,031 milligrams of sodium per day.
The results 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. People who had 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 a day, there were 66 strokes. That compared with 24 strokes among the 320 people who met the AHA guidelines.
Gardener cautioned that they couldn't definitively draw conclusions about cause-and-effect, since people who keep their salt intake in check may be healthier in other ways too.
But she and her colleagues accounted for smoking habits, exercise, education and other health conditions that can contribute to strokes, and there was still a strong correlation between sodium and stroke risk.
Very few people in the United states may be meeting the sodium consumption goals. It's estimated that the typical U.S. man gets 4,000 milligrams of sodium a day, while women typically get 2,800 milligrams - most of it from prepared foods or those eaten in restaurants.
“Certainly the foods popular with Americans are laden with sodium,” Gardener said, suggesting that people read food labels carefully and stick to “whole foods” such as fruits, vegetables and whole grains, as much as possible.
But steps must be taken by the industry and public health officials as well, such as cutting sodium in prepared and restaurant food. - Reuters