Health and Economic Effects of Salt Reduction Interventions for Preventing Noncommunicable Diseases in Japan: A System Dynamics Simulation Study

Reducing salt intake is a vital public health measure for combating noncommunicable diseases and mitigating rising social security expenditures in Japan. We developed a system dynamics model to analyze the potential health and cost effects of salt reduction interventions among the Japanese population aged 40 years and above from 2012 to 2040. The simulation findings derived from the model indicate that, in the base run, the disability-adjusted life years (DALYs) for cardiovascular disease (CVD) and chronic kidney disease (CKD) are projected to be approximately 55 and 9.5 per 100,000 people, respectively, contributing approximately 40 trillion yen in social security expenditures by 2040. The model predicts that implementing mandatory reformulation could decrease DALYs for CVD and CKD by 5.7% and 6.2%, respectively, resulting in an approximately 6.7% reduction in social security expenditure. Additionally, voluntary reformulation is estimated to reduce the DALYs for CVD and CKD by 4.7% and 5.2%, leading to a 5.6% decrease in social security expenditure. Finally, accelerating the adoption of a low-salt diet is expected to lower the DALYs for CVD by 2.8% and CKD by 3.2%, thereby reducing social security expenditures by 3.4%. Thus, product reformulation initiatives have a greater impact on health and economic outcomes.