Systematic Review of Dietary Supplement Efficacy and Safety

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Systematic Review of Dietary Supplement Efficacy
and Safety
AHRQ Annual Meeting September 2008
Paul M. Coates, Ph.D. Office of Dietary
Supplements National Institutes of
Health Department of Health and Human Services
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NIH Funding for Dietary Supplement Research Has
Increased Significantly
Million
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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

Echinacea Echinacea purpurea
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• Evidence-Based Review Program

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Congressional Language for FY 2001 ODS
Appropriation

• The Office is encouraged, in consultation with
  NCCAM, AHRQ, and FDA 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.

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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

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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 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 OMAR)
• Coagulation, diet, and dietary supplements
• Health effects of vitamin D (with multiple
  partners)

Congressional mandate
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Health Effects of Omega-3 Fatty Acids

• Asthma
• Cancer
• Cardiovascular Disease
• 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

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Health Effects of Omega-3 Fatty Acids

• Secondary CVD Prevention
• Reduces all cause mortality and other CVD
  outcomes (sudden death, cardiac death, 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

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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

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Observations

• Nobody expects the Spanish Inquisition (Monty
  Pythons Flying Circus, ca.1970)
• Put another way, nobody expected to be
  meta-analyzed

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Issues in Dietary Supplement Research

• Product Concerns
• Identification
• Characterization
• Reproducibility

St. Johns Wort Hypericum perforatum
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Issues (contd)

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

St. Johns Wort Hypericum perforatum
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Website http//ods.od.nih.gov Email
ods_at_nih.gov