July 11, 2011 -- A diet high in sodium and low in potassium increases the risk of death from heart disease and other causes, according to a new study.
"Americans who eat a diet high in sodium and low in potassium have a 50% increased risk of death from any cause and about about twice the risk of death from heart disease," says researcher Elena V. Kuklina, MD, PhD. She is a nutritional epidemiologist with the CDC division for heart disease and stroke prevention.
Morton Satin, vice president of science and research for the Salt Institute, disagrees with the study. "It's highly flawed and reveals more of this dogmatic anti-salt agenda."
Research about sodium and heart disease has produced conflicting results. Studies have shown that high sodium intake or low potassium intake is linked with a higher risk for high blood pressure, the researchers write. The link is stronger for potassium.
However, the research about a link between intake of sodium and potassium and getting or dying from cardiovascular disease has been less consistent.
The researchers decided to focus on the sodium-potassium ratio. Recent research has suggested the ratio may be more important in explaining the risk for high blood pressure or cardiovascular disease than either alone.
The study is published in the Archives of Internal Medicine.
Kuklina and her colleagues followed 12,267 U.S. adults. They participated in the Third National Health and Nutrition Examination Survey from 1988 to 1994. They answered questions about their diet and had physical exams.
None of those studied was on a reduced salt diet at the start. Anyone with a history of heart problems or stroke was excluded.
The researchers followed them for nearly 15 years. "Using death certificate data, we looked to see if they died and from what causes," Kuklina says.
During the follow-up, 2,270 people died, including 1,268 from cardiovascular disease.
A higher sodium-potassium ratio was associated with an increased risk of death from heart disease as well as other causes.
A sodium intake of 1,500 milligrams a day maximum and potassium intake of 4,700 milligrams a day is considered adequate under the Dietary Guidelines.