Salt Substitutes in Low-Income Settings: Blood Pressure Benefits, Cardiovascular Outcomes, and Safety Considerations: A Narrative Review

Background: Hypertension remains a leading cause of cardiovascular morbidity and mortality, disproportionately affecting low- and middle-income countries (LMICs), where healthcare access and awareness are limited. Excessive sodium intake, often from discretionary salt used in cooking, contributes significantly to this burden. Salt substitutes, typically formulated by partially replacing sodium chloride with potassium chloride or other minerals, offer a cost-effective dietary intervention to lower blood pressure (BP) and reduce cardiovascular risk, particularly in resource-constrained settings. Objective: This review examines the efficacy of low-sodium salt substitutes (LSSS) in reducing blood pressure (BP) and its effects on cardiovascular (CV) outcomes, safety concerns, and challenges to their implementation in LMICs. Methods: We conducted a comprehensive narrative review of studies published between 1994 and 2024 using PubMed, Embase, and Scopus databases. Eligible studies included randomized controlled trials, systematic reviews, observational studies, and implementation research that evaluated the effects of LSSS on BP, CV outcomes, safety, and feasibility in LMIC contexts. Thematic synthesis was used to summarize the findings. Key Findings: Salt substitutes consistently lowered systolic and diastolic BP across diverse populations, with mean reductions ranging from 3 to 5 mmHg. Trials have also demonstrated reductions in stroke incidence, CV events, and all-cause mortality. However, the benefits were mostly derived from studies conducted in China and other upper-middle-income settings. Safety concerns (particularly hyperkalemia in individuals with chronic kidney disease or RAAS inhibitors) warrant targeted risk screening and public education. Implementation barriers in LMICs include cost, limited availability, poor awareness, and a lack of regulatory oversight. Conclusions: Salt substitutes present a promising, scalable strategy to reduce BP and CV disease burden in LMICs. However, their adoption must be context-specific, culturally sensitive, and supported by government subsidies, regulatory frameworks, and educational campaigns. Future trials should evaluate the long-term safety and cost-effectiveness in underrepresented LMIC populations to guide equitable public health interventions.