The review, funded by the NIHR School for Primary Care Research, included just nine small trials, involving a total of 479 participants. None of these studies provided clinically relevant data to determine whether a low-salt diet is associated with a reduced risk of death from heart attack or stroke, hospitalisation or length of hospital stay. However, for patients not in hospital, the authors found no significant evidence of harms from a reduction of dietary salt intake and a trend for some clinical improvements.
Lead author, Dr Kamal Mahtani, an Oxfordshire GP and Associate Professor in the Nuffield Department of Primary Care Health Sciences, said: “ A lot of the guidelines appear to vary in the exact advice they give heart failure patients when it comes to reducing salt intake. Our research highlights a lack of robust, high-quality evidence available to support or refute current guidance.
"When considering a lower salt diet, patients with heart failure should discuss the evidence with their healthcare professional, and come to a shared decision based on both the evidence and the individual circumstances of the patient."
Writing in JAMA Internal Medicine, the research team suggest larger, well-designed studies are needed and recommend that clinicians and policymakers should acknowledge the weak evidence base for heart failure patients when considering a salt-restricted diet.
Full press release from University of Oxford.
Reduced Salt Intake for Heart Failure. A Systematic Review.
Kamal R Mahtani, Carl Heneghan, Igho Onakpoya, Stephanie Tierney, Jeffrey K Aronson, Nia Roberts, F.D Richard Hobbs, David Nunan
JAMA Internal Medicine 2018 doi: 10.1001/jamainternmed.2018.4673
Sodium Restriction in Heart Failure: Too Much Uncertainty—Do the Trials.
JAMA Internal Medicine. 2018. doi:10.1001/jamainternmed.2018.4653