20
Supplements and Functional Foods
Key Points
Potential publication bias
➤ Clinicians should be cautious of the published literature regarding
supplements or other therapies (including drugs) when the only
available evidence is via infrequent and/or small studies.
➤ The disproportionate publication of positive or significant results
compared to negative or non-significant results potentially
compromises the objectivity of literature review and meta-
analyses.
➤ Negative or non-significant study results may not be submitted
for publication, are often less likely to be accepted by journals
for publication, and are potentially less likely to be cited by other
journals and the media compared to studies with positive results.
Drugs are regulated differently than supplements
➤ Supplements do not require a clinical trial development program
acceptable to the FDA and:
• Can be marketed without FDA approval
• Are generally considered safe until proven unsafe
➤ Prescription and OTC medications require a development program
acceptable to the FDA and:
• Cannot be marketed until FDA approved
• Are not considered safe until proven safe
➤ Once approved based upon clinical trial efficacy and safety, the
FDA assigns an "indicated use" for pharmaceuticals. While not
similarly applicable to the health benefits, efficacy or advisability
of supplement consumption, independent organizations such
as United States Pharmacopeia Dietary Supplement Verification
Program (USP verified logo) provide voluntary processes for
supplement quality indicators (monographs), supporting that
what is in the supplement matches what the label says is in
the supplement. Independent testing is also performed by
companies such as ConsumerLab.com.
