A recent Health Affairs article explores the research and controversy about salt regulation as an example of the challenges of evidence-based policymaking. The article notes that most public health leaders have long advocated for reduced salt consumption as a way to reduce the risk of stroke and cardiovascular disease. However, the evidence for salt's impact on these diseases is not universal. While many studies support a reduction in salt intake, others do not, and some recent meta-analyses suggest that the evidence of salt's impact is minor or uncertain.
The authors note that "advocates of salt reduction believe that the lives of hundreds of thousands of people hang in the balance;" but for "those who insist that the evidence for universal salt reduction is weak, the credibility of the scientific enterprise itself is at stake."
The authors argue that policymakers must act even when there is scientific disagreement or uncertainty. Yet, policymakers also should not conceal such uncertainty, because to do so "serves neither the ends of science nor good policy. Simplistic pictures of translation from evidence to action distort our ability to understand how policy is, in fact, made and how it should be made."
The authors also emphasize that judgments and values must play a role in evidence-based policymaking. Certain questions cannot be answered on evidence alone, such as whether the burdens of a public health intervention would be too severe, or the benefits sufficient given the costs.
