Sodium Reduction: Policy Evidence Assessment Report (PEAR)

Background

Reducing sodium consumption can lower blood pressure, especially among adults with hypertension.1 Hypertension is a contributing factor for heart disease and stroke, which are two of the leading causes of death in the United States.2

About 70% of the sodium consumption in the United States is estimated to come from processed food and restaurant meals outside the home.3 Therefore, there is a need for community-based efforts that support public education and healthy food environments that promote reduced sodium intake.4

Policy interventions can be used to help lower population sodium intake. Some of these initiatives include5

About the Report

From October 2018 to June 2019, CDC’s Division for Heart Disease and Stroke Prevention (DHDSP) assessed the best available evidence for six different policy interventions addressed in state or local law that aim to reduce sodium intake in the United States. Each policy addresses different types of evidence-based interventions.

This report, What is the Evidence for State and Local Laws Addressing Sodium Reduction Among the US Adult Population?, assesses the strength and quality of the best available evidence for six policy interventions to reduce sodium consumption among the adult population (aged 18 or older).

Each of these policy interventions was addressed in at least one state or local U.S. law in effect as of January 1, 2019; recommended by subject matter experts on sodium; and addressed in relevant published and grey literature.

The report prioritizes the six sodium reduction policy interventions addressed in state or local law by its current evidence level (“best,” “promising quality,” “promising impact,” or “emerging”).

Results

The following policy interventions demonstrated “best” available evidence, with strong potential public health impact and high quality of evidence:

These policy interventions with “promising” or “emerging” evidence could also have positive impacts, but the quantity and quality of the evidence for public health impact is limited at this time:

Mixed, null, or negative outcomes were associated with 12 studies that were reported within the evidence base:

  • Six within the policy intervention focused on labeling
  • Four within vending machines
  • Two within stores

Note: See the report’s Appendix for a more detailed description of the methodology, including the scoring for both evidence for potential public health impact and evidence quality.

This report focuses on the evidence and outcomes specific to sodium and their relationship with the selected policy interventions. This includes 76 items of evidence; 70 practice-based studies and 6 research-based studies.

Using the Reports

Results of this assessment can be considered a decision aid tool that summarizes evidence-informed interventions supporting sodium reduction.

  • State decision makers and public health organizations may consider researching the health status of their state’s population. CDC offers many health facts on its website, including those related to sodium consumption.
  • Stakeholders may consider presenting this report, along with facts about sodium consumption rates and existing nutrition policies and programs, to state and local public health agencies, health care providers and payers, and others interested in improving health outcomes.
  • Researchers and evaluators could help build stronger evidence for these “promising” and “emerging” policy interventions. They may consider reviewing this report for evidence gaps to be addressed in future studies.

Limitations of This Report

  • This report may include studies based in practice where rigorous designs were not possible due to real-world circumstances. Furthermore, this report includes non-empirical evidence (e.g., expert opinion and theorybuilding narratives) that are not included in systematic reviews.
  • This report focused on interventions to reduce sodium, as opposed to interventions to improve the overall nutritional profile of healthy foods. Studies were excluded if they did not report sodium reduction outcomes. For example, some evidence sought to change the nutritional content of products as a whole by targeting multiple nutrients (i.e., “healthier” products); however, if the independent effect of sodium on the health outcome could not be determined, these studies were excluded. This focus may have excluded potentially supportive articles of some policy interventions.
  • Procurement guidelines are broad and can refer to a number of different settings (e.g., food in vending machines on government property, food served to employees, food served by city agencies). Rather than focusing on the guidelines as a whole, we analyzed these guidelines by setting to ensure the evidence base is applicable to each policy intervention.
  • Key words were used to search and classify the items of evidence. This narrowed the scope and quantity of evidence.
  • This report does not rate the impact of the policy interventions found within existing law, nor does it compare the policy interventions to each other.

Given the nature of these early evidence assessments, the evidence level for each policy intervention may change as impactful, higher-quality evidence becomes available. These evidence levels provide an initial gauge of the current status of the sodium-specific literature related to the selected policy interventions.

References

  1. Whelton PK, Carey RM, Aronow WS, et al. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. J Am Coll Cardiol. 2018;71(19):e127-–e248.
  2. Centers for Disease Control and Prevention. High blood pressure. https://www.cdc.gov/bloodpressure/index.htm. Updated October 2, 2019. Accessed November 12, 2019.
  3. Mugavero KL, Gunn JP, Dunet DO, Bowman BA. Sodium reduction: an important public health strategy for heart health. J Public Health Manag Pract. 2014 Jan-Feb;20(1 Suppl 1):S1-S5.
  4. Harnack LJ, Cogswell ME, Shikany JM, et al. Sources of sodium in US adults from 3 geographic regions. Circulation. 2017;135(19):1775-1783.
  5. Centers for Disease Control and Prevention. CDC grand rounds: dietary sodium reduction-time for choice. MMWR Morb Mortal Wkly Rep. 2012;61(5):89.
  6. Centers for Disease Control and Prevention. Definition of policy. http://intranet.cdc.gov/od/adp/od/policyDef.htm.
  7. Barbero C, Gilchrist S, Shantharam S, Fulmer E, Schooley MW. Doing more with more: How “early” evidence can inform public policies. Public Adm Rev. 2017;77(5):646-649.

Disclaimer: The findings and conclusions of this document are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention. Furthermore, this document is not intended to promote any particular legislative, regulatory, or other action.

Suggested Citation

Centers for Disease Control and Prevention. What Is the Evidence for State and Local Laws Addressing Sodium Reduction Interventions Among the US Adult Population? A Policy Evidence Assessment Report. Atlanta, GA: Centers for Disease Control and Prevention, US Department of Health and Human Services; 2019.