Salt substitutes cut risk of death from all causes, study shows

Salt harvesting in France. Salt substitutes, in which a proportion of sodium chloride is replaced with potassium chloride, are known to help to lower blood pressure. Reuters

Salt substitutes lower the risk of heart attack, stroke, and death from all causes and cardiovascular disease, a new analysis of data has found.

A Chinese study — the salt substitute and stroke study (SSaSS) — previously identified health benefits of salt substitutes. However, it was not known if its findings could be extrapolated globally.

Now it appears the benefits of the low sodium diet are likely to apply to people all around the world, say the research published online in the journal Heart.

“Since blood pressure lowering is the mechanism by which salt substitutes confer their cardiovascular protection, the observed consistent blood pressure reductions make a strong case for generalisability of the cardiovascular protective effect observed in the SSaSS both outside of China and beyond,” researchers wrote.

“These findings … support the adoption of salt substitutes in clinical practice and public health policy as a strategy to reduce dietary sodium intake, increase dietary potassium intake, lower blood pressure and prevent major cardiovascular events.”

Cardiovascular disease is a leading cause of death worldwide, and high blood pressure is a major risk for an early death.

A diet high in sodium and low in potassium is known to drive up blood pressure.

About 1.28 billion people around the world have high blood pressure, although more than half of these are undiagnosed, say the researchers.

Salt substitutes, in which a proportion of sodium chloride is replaced with potassium chloride, are known to help to lower blood pressure.

Researchers analysed databases of 21 randomised clinical trials looking at the effects of a salt substitute on blood pressure, cardiovascular health, and early death.

The studies involved nearly 30,000 people in Europe, the western Pacific region, the Americas, and South-East Asia.

The proportion of sodium chloride in the salt substitutes varied from 33 per cent to 75 per cent and the proportion of potassium ranged from 25 per cent to 65 per cent.

The pooled data analysis showed salt substitutes lowered blood pressure in all the participants.

In five of the trials, involving more than 24,000 participants, salt substitutes lowered the risks of early death from any cause by 11 per cent, from cardiovascular disease by 13 per cent, and the risks of heart attack or stroke by 11 per cent.

Researchers said there were limitations to their findings, including that the studies in the pooled data analysis varied in design and that there were relatively few data for people who did not have high blood pressure.