In a systematic review published by The Cochrane Library, British scientists found that while cutting salt consumption did appear to lead to slight reductions in blood pressure, that was not translated into lower death or heart disease risk.
The researchers said they suspected the trials conducted so far were not big enough to show any benefits to heart health, and called for large-scale studies to be carried out soon.
"With governments setting ever lower targets for salt intake and food manufacturers working to remove it from their products, it's really important that we do some large research trials to get a full understanding of the benefits and risks of reducing salt intake," said Rod Taylor of Exeter University, who led the review.
The Cochrane review attracted sharp criticism from nutrition experts. Francesco Cappuccio, head of the World Health Organization's collaborating centre for nutrition at Warwick University, said it was "a surprisingly poor piece of work."
Simon Capewell, a professor of Clinical Epidemiology at Liverpool University, said the review was "disappointing and inconclusive" and did not change public health consensus that dietary salt raises blood pressure.
Most experts are agreed that consuming too much salt is not good for you and that cutting salt intake can reduce hypertension in people with normal and high blood pressure.
Many developed nations have government-sanctioned guidelines calling on people to cut their salt or sodium intake for the sake of their longer-term health. The World Health Organization (WHO) lists reducing salt intake among its top 10 "best buys" for reducing rates of chronic disease.