Herbal medicine: Show me the proof!

CMAJ 1998;158:1689

• Letter: Evaluating unconventional therapies

However, I am curious to learn that these substances are "natural." Is this true? Is no manufacturing process used in their production? She also states that "there is a conviction" that there is little to choose between these potions and synthetic pharmaceuticals, but conviction is not proof — unfortunately, though, the road to clinical hell is paved with strong convictions that are subsequently found wanting. Ten years ago we were convinced that peptic ulcer disease was due to a complex psychosomatic process, a theory that has since been relegated to the ash can of etiologic speculation. If an herb happens to ameliorate symptoms, the effect may be due to a placebo effect, especially among patients disenchanted with modern medical pharmacology.

Curiously, herbal compounds appear to have no value in treating acute illness. Although these herbs — it is politically incorrect to call them drugs yet because profits may tumble — may have active ingredients, as Ken Keirstead was quoted as stating, there is little if any scientific evidence that they really do anything. Is St. John's wort significantly better than placebo in carefully conducted clinical trials? Does Ginkgo biloba really increase oxygen supply to the brain in patients with Alzheimer's disease, as CNN informed me the other night? Most puzzling is the fact that the prestigious US National Institutes of Health has bowed to the media darlings and received funding for research involving "alternative medicine."

And most surprising of all is that organized medicine raises not a whimper about all of this. Science, I would have thought, is the only means we have to separate the truth from whim, fraud and, of course, simple stupidity!

Noel B. Hershfield, MD
Clinical Professor
Department of Medicine
University of Calgary
Calgary, Alta.

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