Systematic Review of Dietary Supplement Efficacy and Safety (Text Version)

AHRQ 2008 Annual Conference

Slide Presentation from the AHRQ 2008 Annual Conference

On September 10, 2008, Paul H. Coates, made this presentation at the 2008 Annual Conference. Select to access the PowerPoint® presentation (1.7 MB; Plugin Software Help).

Slide 1

Systematic Review of Dietary Supplement Efficacy and Safety

• AHRQ Annual Meeting
  September 2008
• Paul H. Coates, Ph.D.
  Office of Dietary Supplements (ODS)
  National Institutes of Health (NIH)
  Department of Heath and Human Services

Slide 2

Net Funding for Dietary Supplement (DS) Research Has Increased Significantly

• Bar graph shows annual funding totals in billions of dollars (figures here are estimates of where the tips of bars reach):
  • 1999: $100 million.
  • 2000: $120 million.
  • 2001: $125 million.
  • 2002: $160 million.
  • 2003: $252 million.
  • 2004: $255 million.
  • 2005: $300 million.
  • 2006: $252 million.

• Note: NIH funding for dietary supplement research has increased significantly over the last several years. From $100 million in 1999, the total funding for this research has risen to between $250 million and $300 million per year for the last 4 reporting years.

Slide 3

ODS Mission Is to Strengthen Knowledge and Understanding of Dietary Supplements

• Evaluate Scientific Information.
• Stimulate and Support Research.
• Disseminate Research Results.
• Educate the Public to Foster an Enhanced Quality of Life and Health for U.S. Population.

• (Photo shows Echinacea, Echinacea purpurea).

Slide 4

Evidence-Based Review Program

Slide 5

Congressional Language for Fiscal Year 2001 ODS Appropriation

• "The Office is encouraged, in consultation with NCCAM [National Center for Complementary and Alternative Medicine], AHRQ [Agency for Healthcare Research and Quality], and FDA [Food and Drug Administration] to review the current scientific evidence on the safety and efficacy of dietary supplements now on the market, which could then form a basis for further research, education of practitioners and consumers, and whether further regulatory requirements are necessary."

Slide 6

Evidence-Based Review Program

• Systematic review of the literature, with meta-analysis as appropriate, on DS efficacy and safety.
• In collaboration with the Agency for Healthcare Research and Quality (AHRQ) Evidence-Based Practice Center Network.
• Major reason for conducting these reviews is to assist NIH in the development of research agendas.

Slide 7

ODS Evidence-Based Review Program

• Chromium and insulin sensitivity*
• Ephedra for weight management and athletic performance enhancement* (with NCCAM).
• Omega-3 fatty acids for cardiovascular disease prevention* with (National Heart, Lung and Blood Institute [NHLBI]) and other health indications.
• Health effects of soy (with NCCAM).
• Antioxidant phytochemicals/B vitamins and neurodegenerative diseases* (with NCCAM).
• Multivitamins/multiminerals and chronic disease prevention (with Office of Medical Application and Research [OMAR].
• Coagulation, diet, and dietary supplements.
• Health effects of vitamin D (with multiple partners).

• Congressional mandate.

Slide 8

Health Effects of Omega-3 Fatty Acids

• Asthma.
• Cancer.
• Cardiovascular Disease (CVD).
• Cardiovascular Disease Risk Factors.
• Arrhythmogenic Mechanisms.
• Child and Maternal Health.
• Cognitive Function.
• Eye Health.
• Type II Diabetes, Rheumatoid Arthritis, and Other Diseases.
• Mental Health.
• Organ Transplantation.

Slide 9

Health Effects of Omega-3 Fatty Acids

• Secondary CVD Prevention.
  • Reduces all cause mortality and other CVD outcomes (sudden death, cardiac death, myocardial infarction [MI]).
• Primary CVD Prevention.
  • Large, consistent beneficial effect found for serum triglyceride levels.
  • Little or no effect found for other CV risk factors and markers of CVD.

Slide 10

Omega-3 Reports

• Heterogeneous data; challenging to evaluate.
  • Methods of estimating fish or omega-3 fatty acid intake.
  • Background diets.
  • Methods of reporting results.
• Adverse events from clinical studies appear to be minor.
  • However, reporting is spotty.

Slide 11

Observations

• "Nobody expects the Spanish Inquisition."
  • (Monty Python's Flying Circus, ca. 1970).
  • (Photo shows Monty Python players dressed as inquisitors).
• Put another way, nobody expected to be meta-analyzed.

Slide 12

Issues in Dietary Supplement Research

• Product Concerns:
  • Identification.
  • Characterization.
  • Reproducibility.
• (Photo shows St. John's Wort, Hypericum perforatum).

Slide 13

Issues (cont'd)

• Protocol Concerns:
• Population(s).
• Endpoints.
• Dose.
• Earlier Phase Studies.
• Publication.

Slide 14

Office of Dietary Supplements

• Web site: http://ods.od.nih.gov
• E-mail: ods@nih.gov