A low salt diet is often recommended for heart failure — but the evidence is lacking, experts say.
The researchers from the Centre of Evidence Based Medicine at the University of Oxford in the UK analysed data from nine studies involving 479 participants.
They discovered big gaps in the research — most notably, they found no clinically relevant data on whether a reduced salt intake in people with heart failure affected outcomes such as cardiovascular-associated or all-cause mortality, cardiovascular associated events or hospitalisation.
This was a major concern given that advice to reduce salt intake is recommended in several international cardiovascular guidelines, they said.
“Despite broad advocacy, uncertainty about the robustness of advice to reduce salt intake in patients with heart failure remains,” the review authors concluded in their study published in JAMA Internal Medicine.
Writing in an accompanying editorial cardiologist Clyde Yancy from the NorthWestern University Feinberg School of Medicine in Chicago described the failure by the authors to find evidence of an “important clinical benefit” [of a low salt diet] as a “pause moment”.
“It is incredulous that in our evidence-based era, we have accepted such a low bar for this particular bedrock recommendation of cardiovascular care,” he wrote.
Describing the gap between evidence and practice as an “abyss” he concluded that we “must make the painful deduction that the current evidence base addressing sodium restriction in heart failure is vacuous, lacks depth, and in some cases lacks integrity”.
The first step was not a call for more trials but rather a retreat from an “unbridled and potentially harmful insistence on rigorous sodium restriction in those with symptomatic heart failure”.
“To state that we can do better is an understatement; to acknowledge our embarrassment for acting upon uncertain logic is closer to the truth,” he added.