The Health and Cost Impacts of Interventions Designed to Reduce Dietary Sodium Intake in Australia: A Modeling Study

Excess dietary sodium contributes significantly to preventable morbidity and mortality in Australia.

We estimated the health and economic impacts over 20 years for different sodium reduction interventions in Australia (population 25.3 million).

Nine sodium interventions (4 reformulation, 3 potassium substitution, and 2 mass media campaigns) were modeled as changes in sodium over time, including associated industry and government costs. A proportional multistate lifetable model simulated long-term impacts of sodium reduction across the Australian population, incorporating current (business-as-usual) trends in sodium intake, systolic blood pressure (SBP), disease rates, health expenditure and income loss by sex, age, and socioeconomic group. Change in sodium was linked to change in SBP (varying by age and initial SBP), thence to disease rates. Outcomes included gains in health-adjusted life years (HALYs), and changes in health inequalities, health expenditure, and population income.

Achieving the WHO reformulation targets in Australia generated 40,100 HALYs (95% UI: 27,200, 56,700). The Australian and United Kingdom (UK) reformulation targets achieved 28% and 63% of this gain. Potassium substitution for sodium (10% in all foods, 30% in discretionary salt) achieved 15,600 and 13,100 HALYs gained, respectively. A UK-style mass media campaign generated 1130 HALYs. All interventions delivered around twice the HALY gains per capita among more disadvantaged populations and modestly reduced the mortality gap by 2044. Achieving WHO reformulation targets cost industry and government about AUS$0.5 billion but saved AUS$0.9 billion in disease expenditure (even with longer lives generating more costs). Citizen income increased by AUS$0.9 billion (with about a quarter returned as tax) and could grow further with improved income among healthier 65+ adults. All interventions led to net savings, except the mass media campaign, where the upfront costs exceeded future savings.

Sodium interventions offer a triple-win: health gains, health inequality reductions and economic gains from all perspectives.