Despite efforts over the past several decades to reduce sodium intake in the United States, adults still consume an average of 3,400 mg of sodium every day. A number of scientific bodies and professional health organizations, including the American Heart Association, the American Medical Association, and the American Public Health Association, support reducing dietary sodium intake. These organizations support a common goal to reduce daily sodium intake to less than 2,300 milligrams and further reduce intake to 1,500 mg among persons who are 51 years of age and older and those of any age who are African-American or have hypertension, diabetes, or chronic kidney disease.

A substantial body of evidence supports these efforts to reduce sodium intake. This evidence links excessive dietary sodium to high blood pressure, a surrogate marker for cardiovascular disease (CVD), stroke, and cardiac-related mortality. However, concerns have been raised that a low sodium intake may adversely affect certain risk factors, including blood lipids and insulin resistance, and thus potentially increase risk of heart disease and stroke. In fact, several recent reports have challenged sodium reduction in the population as a strategy to reduce this risk.

Sodium Intake in Populations recognizes the limitations of the available evidence, and explains that there is no consistent evidence to support an association between sodium intake and either a beneficial or adverse effect on most direct health outcomes other than some CVD outcomes (including stroke and CVD mortality) and all-cause mortality. Some evidence suggested that decreasing sodium intake could possibly reduce the risk of gastric cancer. However, the evidence was too limited to conclude the converse—that higher sodium intake could possibly increase the risk of gastric cancer. Interpreting these findings was particularly challenging because most studies were conducted outside the United States in populations consuming much higher levels of sodium than those consumed in this country. Sodium Intake in Populations is a summary of the findings and conclusions on evidence for associations between sodium intake and risk of CVD-related events and mortality.

Contents

• THE NATIONAL ACADEMIES
• COMMITTEE ON THE CONSEQUENCES OF SODIUM REDUCTION IN POPULATIONS
• Reviewers
• Preface
• Summary
  • COMMITTEE TASK AND APPROACH
  • FINDINGS AND CONCLUSIONS
  • FUTURE RESEARCH TO ADDRESS GAPS IN DATA AND METHODOLOGY
• 1. Introduction
  • BACKGROUND
  • THE COMMITTEE'S TASK
  • THE STUDY PROCESS
  • ORGANIZATION OF THE REPORT
  • REFERENCES
• 2. Approach to Evidence Review
  • GENERAL APPROACH OF THE COMMITTEE
  • LITERATURE REVIEW
  • EVALUATION OF STUDIES
  • METHODOLOGICAL ISSUES IN SODIUM RESEARCH: SODIUM INTAKE ASSESSMENT
  • REFERENCES
• 3. Sodium Intake and Intermediate Markers for Health Outcomes
  • BACKGROUND
  • BLOOD PRESSURE AS A BIOMARKER FOR CARDIOVASCULAR DISEASE
  • EVIDENCE ASSOCIATING SODIUM INTAKE WITH BLOOD PRESSURE
  • EVIDENCE ASSOCIATING SODIUM INTAKE WITH BIOMARKERS OF PROGRESSION OF PRIOR KIDNEY DISEASE
  • REFERENCES
• 4. Sodium Intake and Health Outcomes
  • CARDIOVASCULAR DISEASE, STROKE, AND MORTALITY
  • SYNTHESIS OF THE EVIDENCE
  • STUDIES ON KIDNEY DISEASE
  • STUDIES ON METABOLIC SYNDROME, DIABETES, AND GASTRIC CANCER
  • ADDITIONAL HEALTH OUTCOMES
  • REFERENCES
• 5. Findings and Conclusions
  • INTRODUCTION
  • FINDINGS AND CONCLUSIONS
  • FUTURE RESEARCH TO ADDRESS GAPS IN DATA AND METHODOLOGY
  • REFERENCES
• APPENDIXES
  • Appendix A Acronyms and Abbreviations
  • Appendix B Committee Member Biographical Sketches
  • Appendix C Open Session Agendas
  • Appendix D Biomarkers Figure
  • Appendix E Literature Search Strategy
  • Appendix F Presentation of Results—Evidence Tables

This study was supported by Contract/Grant No. 200-2011-38807 between the National Academy of Sciences and the Centers for Disease Control and Prevention. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the organizations or agencies that provided support for the project.

Suggested citation:

IOM (Institute of Medicine). 2013. Sodium intake in populations: Assessment of evidence. Washington, DC: The National Academies Press.

NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the committee responsible for the report were chosen for their special competences and with regard for appropriate balance.