If you have heart failure, there's good news and bad news on how much it would help you to cut back on salt.
New research finds that while it doesn't prevent death or hospitalization among patients, it does appear to improve their quality of life.
Patients with heart failure have been told for years to reduce the salt in their diet as a way to help prolong life, but among more than 800 patients from six countries, reducing salt intake didn't prevent deaths, visits to the emergency room or hospitalizations, the researchers found.
Still, "we do think that there is a small amount to be gained by reducing the amount of sodium in the diet," said researcher Dr. Justin Ezekowitz, a professor in the division of cardiology at the University of Alberta in Edmonton, Canada.
The patients in the study were already eating a lot less salt than most Americans consume, although they had not achieved the optimal goal of the amount of salt recommended, he explained.
"The expected goal is not reducing clinical events necessarily, but it does improve quality of life, which might be very important for individual patients," Ezekowitz said.
For the study, the research team followed heart failure patients from 26 medical centers in Australia, Canada, Colombia, Chile, Mexico and New Zealand. Half were randomly assigned to receive usual care, and the rest received nutritional counseling on how to further reduce their dietary salt intake.
Patients who received counseling were given menu suggestions and encouraged to cook at home and not add salt. They were also urged to avoid salty foods.
Patients were asked to keep their salt intake to 1,500 milligrams (mg) per day - about two-thirds of a teaspoon. Before the study, patients added an average of 2,217 mg per day, or about one teaspoon. After one year, those not receiving nutritional advice ate an average of 2,072 mg of salt daily, while those who received nutritional guidance ate 1,658 mg per day.
Although Ezekowitz's group didn't find significant differences in deaths or hospitalizations between the two groups of patients, those on the low-salt diet did show improvement in quality of life and in the severity of their heart failure.
Ezekowitz thinks that these results might have been different if the study had gone on longer or if the levels of salt consumption had been even lower.
The findings are not a license to eat as much salt as you like, he added.
"People should continue to be concerned about the amount of salt in their diet and continue to reduce the sodium in their diet overall," Ezekowitz said. "There may be benefits that we didn't measure in our clinical trial that they might get from reducing salt in the diet. A low-salt diet may actually improve their overall quality of life. The real take-home is that a low-sodium diet remains an important part for most patients."
The report was published online April 2 in The Lancet journal and was presented at the American College of Cardiology annual meeting in Washington, D.C.
Dr. Gregg Fonarow, interim chief of the division of cardiology at University of California, Los Angeles, said for decades patients with heart failure have been advised to restrict their salt intake.
"This longstanding, widely accepted recommendation was based on a physiologic rationale, clinical observation and expert opinion rather than having been demonstrated in prospective, randomized clinical trials," he noted.
While more recent guidelines for heart failure have acknowledged the uncertainty about the benefits of reducing salt, many patients have still been told to reduce their salt to very low levels, Fonarow said.
"The evidence from this very important randomized clinical trial suggests that dietary sodium restriction to a target of less than 1,500 mg per day in patients with heart failure did not reduce mortality, cardiovascular-related hospitalization or cardiovascular-related emergency room visits," he said.
For patients with heart failure, it remains unclear whether any level of salt restriction offers clinical benefits, Fonarow said.
"Yet it is important to keep in mind the usual care comparison group was consuming a little over 2,000 mg of sodium daily, which is still lower than the 3,400 mg of sodium that is the average amount consumed in the U.S. by the general population," he said.
Patients with heart failure should discuss with their doctor how these new findings might apply to them, Fonarow said.
The key to living with heart failure is to follow the proven treatment advice, he said.
"Importantly, use and adherence to disease-modifying guidelines and medical therapy have been shown to be the best and safest way to improve clinical outcomes for patients with heart failure," Fonarow said.
For more on salt and heart health, head to the American Heart Association.
SOURCES: Justin Ezekowitz, MBBCh, professor, division of cardiology, University of Alberta, Edmonton, Canada; Gregg Fonarow, MD, interim chief, UCLA Division of Cardiology, Los Angeles; The Lancet, April 2, 2022, online