Salt intake was not associated with an increased risk of mortality or cardiovascular disease and health failure among older adults, according to a study published Monday. But experts warn the findings should not be construed to support a change in current government health recommendations regarding recommended daily sodium intake.
Among the 881 (of 2,400) study participants who died after a 10-year period, those who reported consuming less than 1,500 mg of sodium daily had a mortality rate of 34%, compared with a 30% death rate among those who consumed between 1,500 and 2,300 mg of sodium.
Those who reported consuming more than 2,300 mg of sodium a day had a mortality rate of 35%. Among the more than 1,900 who did not have cardiovascular disease at the start of the study, 29% of those who reported a daily sodium intake of less than 1,500 mg had developed cardiovascular disease by the end of the 10-year period.
Those with sodium intake between 1,500 mg and 2,300 mg had an incidence rate of 28% for developing cardiovascular disease, while 30% of those who reported consuming more than 2,300 mg of salt a day developed cardiovascular disease.
The findings would seem to conflict with the federal government's current daily dietary guidelines for sodium consumption, which recommend less than 2,300 mg of salt a day for everyone above the age of 2, while those above the age of 50 should consume less than 1,500 mg. But study author Dr. Andreas Kalogeropoulos is quick to point out that additional research is needed before any conclusions can be made that would prompt any change in the current guidelines.
“I would not be concerned with the findings having an adverse impact on patients' perceptions about salt intake because we did not find any clear benefit with very low salt intake, but we did not find any signal of harm either,” said Kalogeropoulos, a professor of medicine at Emory University's cardiology division.
The study was based on answers given by patients who he said have a tendency to under-report the amount of salt they consume, Kalogeropoulos added.
“Asking people what they ate does not give you a very accurate reading of how much sodium they consume over the long term,” said Bonnie Liebman, director of Nutrition at the Center for Science in the Public Interest, a consumer health advocacy group.
For years advocates have called on the federal government to take a stronger regulatory stance regarding the amount of salt that food companies and restaurants are allowed to put in food.
In an interview with the Associated Press last June, Food and Drug Administration Commissioner Dr. Margaret Hamburg said the agency was looking to issue voluntary standards for the amounts of salt that food companies and restaurant add to their products “relatively soon,” but did not lay out a more exact timetable. The agency said in 2013 it hoped to have such guidelines published by 2014.
Americans consume on average more than 3,400 mg of sodium a day. The Dietary Guidelines of America recommend people over the age of 50, African-Americans and those with high blood pressure, diabetes or chronic kidney disease, maintain a daily salt intake of no more than 1,500 milligrams a day.
Findings from past studies have raised questions about whether the federal government's guidelines regarding daily sodium consumption were too low in some instances. A study published last August in the New England Journal of Medicine found that recommendations calling for no more than 1,500 mg of sodium a day might be too low and pose a health risk for some.
But Liebman called those findings “suspect,” saying that a sodium intake of less than 1,500 mg of sodium a day was “very unusual” and was usually associated with those who were not eating very much because of illness.
“It's a problem called reverse causation,” Liebman said. “It's not low sodium that's increasing their risk of cardiovascular disease or their risk of dying it's that their illness is causing them to eat less sodium—it's the reverse of how it appears.”
The study, published online Monday in JAMA Internal Medicine, analyzed data over 10 years from more than 2,400 adults between the ages of 71 and 80 who were asked to estimate their daily salt intake.
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