Salt substitutes and heart health: what 34 trials show

A 2026 network meta-analysis of 34 randomised trials (37,063 participants in 15 countries) estimated that moderate-potassium, low-sodium salt substitutes lower systolic blood pressure by 4.39 to 4.64 mmHg compared with regular salt. The authors also rated them as probably reducing deaths and cardiovascular events. Most of that mortality evidence comes from one large trial in China, which limits how far it travels.

What did the network meta-analysis compare?

Lai et al., BMC Medicine 2026 searched literature up to 3 October 2025 for randomised trials in adults comparing salt substitutes with regular salt, other substitutes or no intervention. The strongest signals came from moderate-potassium, low-sodium formulations (25 to 40% potassium chloride, 60 to 79% sodium chloride).

Against regular salt, these formulations probably reduced all-cause mortality, cardiovascular mortality, non-fatal cardiovascular events and systolic blood pressure, on moderate to high certainty evidence. The mortality estimate depended on baseline risk: 7 fewer deaths per 1,000 people at intermediate risk (62 per 1,000 over five years) and 17 fewer at high risk (143 per 1,000), as modelled by the authors.

What are the limits of the salt substitute evidence?

The authors say the benefit for mortality and cardiovascular events is dominated by one large Chinese trial, SSaSS (20,995 participants), and that none of the non-Chinese studies contributed mortality data. Generalisability beyond populations with high discretionary salt use is very limited.

SSaSS was an open-label, cluster-randomised trial in rural China with a mean follow-up of 4.74 years. Participants had a mean age of 65.4 years, 72.6% had a history of stroke and 88.4% a history of hypertension. Stroke occurred at 29.14 per 1,000 person-years with the substitute versus 33.65 with regular salt (rate ratio 0.86, 95% CI 0.77 to 0.96). Serious hyperkalaemia events were 3.35 versus 3.30 per 1,000 person-years.

The data are thinner for other groups. Sixteen of the meta-analysed trials excluded people with renal impairment, and the authors state that safety concerns persist for chronic or undiagnosed kidney disease, and that people taking potassium-sparing diuretics or with diabetes may be more susceptible to hyperkalaemia. Air quality is another exposure studied for its effect on blood pressure.

The bottom line

• Across 34 trials, moderate-potassium, low-sodium substitutes lowered systolic blood pressure by 4.39 to 4.64 mmHg versus regular salt (moderate to high certainty).
• Estimated mortality reductions of 7 to 17 per 1,000 people over five years depend on one large Chinese trial, with limited generalisability.
• The authors state safety concerns persist for kidney disease, potassium-sparing diuretics and diabetes, and 16 trials excluded people with renal impairment.