| Popis: |
Both high sodium intake and low potassium intake are associated with high blood pressure and risk of cardiovascular diseases. Potassium-enriched sodium-reduced salt substitutes, in which a certain amount of sodium chloride is replaced by potassium chloride, can lower blood pressure. This is achieved both through reducing sodium intake and increasing potassium intake and may be a cost-effective, scalable, and sustainable approach to reducing blood pressure and cardiovascular diseases at the population level. This thesis develops the knowledge base required to inform the scale-up of salt substitutes as a population salt reduction strategy. The thesis comprises five interrelated but independent studies. First, a literature review summarised evidence about salt reduction and the potential of salt substitution. Second, a systematic review and meta-analysis assessed the effects of salt substitutes on blood pressure and clinical outcomes. Third, a secondary analysis quantified the use of a salt substitute among participants in a large trial. Forth, an environmental scan described the availability, formulation, labelling and price of salt substitutes globally. Lastly, a qualitative study identified facilitators and barriers associated with the scale-up of the salt substitute. The systematic review and meta-analysis found that salt substitutes lowered blood pressure across diverse population subgroups and geographies and had clear protective effects on total mortality, fatal and nonfatal cardiovascular events. The clinical outcome data were derived mostly from one large-scale pragmatic trial, the Salt substitute and Stroke Study (SSaSS), where the effects were achieved by replacing three-quarters of regular salt with reduced-sodium potassium-enriched salt. This level of replacement would be a plausible target for many other jurisdictions. But we found that salt substitutes were available in only 47 countries, of which 60% were high-income countries. The compositions and prices of identified salt substitutes varied substantially, with prices consistently above those of regular salt. Interviews with key informants showed that the taste and price of salt substitutes compared to regular salt, the awareness of the health benefits of salt substitutes, and safety concerns in individuals vulnerable to hyperkalaemia were important factors influencing how widely salt substitutes would be adopted. In conclusion, the thesis findings support the notion that salt substitutes could be scaled as an important population-level strategy to reduce dietary sodium intake, increase potassium intake, reduce blood pressure, and further prevent major cardiovascular and cerebrovascular events. However, the thesis findings highlight multiple potential challenges and the need to identify tailored implementation strategies that will address different barriers in various jurisdictions. |
