Reduced sodium intake improves symptoms of heart failure, study finds

A recent study by the University of Alberta in Canada found that reducing the salt intake of patients with heart failure helps with overall quality of life and symptoms of swelling, fatigue, and coughing, however, it does not reduce emergency visits, hospitalizations, or deaths.

The study, published in The Lancet, was led by Justin Ezekowitz, MSc, FRCPC, professor at the University of Alberta’s Faculty of Medicine and Dentistry and co-director of the Canadian VIGOUR Centre. The study involved 806 patients suffering from heart failure at 26 medical centers in Canada, the United States, Columbia, Chile, Mexico, and New Zealand. The patients were split into two groups: one group received usual care while the other group was counseled by a nutritionist on how to reduce their sodium intake. After 12 months, researchers measured patients’ salt intake, quality of life, and heart failure severity. Death rates of any cause and hospital visits were also tracked throughout the study period.

The target sodium intake for those in the counseled group was 1,500 milligrams (mg)  a day. Prior to the study, the average sodium intake among the study’s participants was 2,217 mg a day. After one year of the study, patients in the usual care group consumed an average of 2,072 mg a day, whereas the group guided by nutritionists consumed an average of 1,658 mg per day.

The study found no statistically significant difference in death rates or hospitalizations among the two groups. Using quality of life assessment tools, as well as the New York Heart Association heart failure classification, they found consistent improvements in quality of life and heart failure symptoms among the low-sodium group.

The study’s researchers plan to continue to track these patients for five years to see the long-term effects of reduced sodium. According to Ezekowitz, who is also a cardiologist at the Mazankowski Alberta Heart Institute, a low sodium diet should still be recommended to patients with heart failure, however it’s important to be realistic about the expected benefits.

"We can no longer put a blanket recommendation across all patients and say that limiting sodium intake is going to reduce your chances of either dying or being in hospital, but I can say comfortably that it could improve people's quality of life overall," said Ezekowitz in a statement.