A salt substitute containing 75% sodium chloride and 25% potassium chloride may reduce the risk of recurrent stroke and mortality in patients who have experienced a prior stroke, according to a new analysis of data from the Salt Substitute and Stroke Study.

In the cluster-randomized trial—results of which were published in JAMA Cardiology—investigators recruited 15,249 patients who experienced strokes from 600 northern Chinese villages. They found a 14% reduction in recurrent stroke events and a 12% reduction in all-cause mortality over approximately 5 years of follow-up with the use of the salt substitute. The intervention appeared particularly effective for managing hemorrhagic stroke, showing a 30% relative risk reduction compared with regular salt use.

"This study provides systematic and quantifiable evidence [of] the effects of using salt substitutes among patients with stroke," the study authors reported. The findings included a 21% reduction in stroke-related mortality, and a modest but clinically meaningful reduction in systolic blood pressure of –2.05 mmHg, with no increased risk of hyperkalemia.

The study population had a mean age of 64.1 years, 45.9% were female, and 84.6% had a history of hypertension at baseline. After the median follow-up period of 61.2 months, the investigators documented 2,735 recurrent stroke events (691 fatal and 2,044 nonfatal) and 3,242 deaths total.

"The direct evidence of salt substitution that we observed could be attributable to the [blood pressure]–lowering effect of reduced-sodium and added-potassium salt," the study authors noted.

The intervention's cost-effectiveness may be particularly relevant for rural populations. The investigators reported that salt substitute in China costs only slightly more than regular salt ($1.62/kg vs $1.08/kg), and previous analyses showed the intervention to be cost-effective.

Study limitations included the open-label design and lack of data on stroke duration/severity, dietary intake, physical activity, and level of debilitation among survivors. However, the investigators emphasized that outcomes were ascertained through standardized methods and verified by an independent adjudication committee blinded to treatment assignment.

The findings suggested that salt substitution could serve as a practical public health strategy, particularly in regions where most sodium intake comes from salt added during home cooking. The investigators concluded that "when scaled up and sustained over time, the simple intervention of salt substitution could significantly improve secondary prevention of stroke and cardiovascular health on a global scale."

The study was funded by grants from the Australian National Health and Medical Research Council and supported by the Kunshan Municipal Government. The salt substitute was provided at no cost by Jiangsu Sinokone Technology Co Ltd. Full disclosures can be found in the study.