Studies
of Herbal Medicine
Found Inadequate
(HealthScoutNews)
-- In a wide-ranging critique of herbal medicines, a Dutch scientist
reports that a lack of regulation and scientifically rigorous
research damages the safety and efficacy of the alternative remedies
that are taking up increasing space in the nation's medicine cabinets.
Faced with the popularity of herbal
remedies like St. John's wort, ginkgo and saw palmetto, it is
incumbent upon doctors to take a more active role in advising
patients about the non-regulated substances, says pharmacist Peter
A.G.M. DeSmet of the Scientific Institute Dutch Pharmacists in
The Hague.
"It is imperative to ask patients
whether they are taking herbal products, particularly when they
present with an unexplained health problem. Clinicians must be
informed about the potential effects of herbal preparations and
must be able to discuss this subject in a non-judgmental way,"
DeSmet writes in today's issue of The New England Journal of
Medicine.
His review article was accompanied
by two essays in the journal calling for more research and regulation
of the exploding herbal medicine market. About 10 percent of Americans
now take them, according to the U.S. Centers for Disease Control
and Prevention.
"The sale of herbal medicines
ought to be based on reasonable evidence that they do something
and that they're safe, but the information people now have to
guide them ranges from misleading to wrong," says Dr. Donald
Marcus, an immunologist at Texas' Baylor College of Medicine and
author of one of the essays.
Other serious problems, he says,
are that many herbal products contain undisclosed and possibly
dangerous prescription or over-the-counter drugs, and that the
labels on herbal medicines offer little information about possible
adverse effects.
"The adulteration issue is
a very real one," he says, citing as an example a 1998 California
Department of Health report that found that 32 percent of Asian
patent medicines sold in the state contained undeclared drugs
such as ephedrine, lead, mercury and arsenic.
"Also, accurate labeling including
real warnings should be on herbal products," he says.
Ginkgo is a very popular herbal
product that is supposed to improve memory. However, he says,
the herb can affect blood platelets and can be dangerous for people
who are already taking anticoagulants to thin their blood. Yet
the labeling on most ginkgo pill bottles recommends only that
people check with their doctors.
While prescription drugs must undergo
rigorous testing before being approved for sale by the U.S. Food
and Drug Administration (FDA), herbal products must only conform
to the much less onerous 1994 Dietary Supplement and Health Education
Act, which defines herbs as dietary supplements. As such, while
holding herbal manufacturers responsible for the truthfulness
of the claims they make about their product, the law requires
no evidence to back up those claims.
For the past five years, the FDA
has been working with the herbal industry to set up more stringent,
mandatory manufacturing guidelines for herbal products, the authors
report, but the guidelines are not yet completed.
Marcus, in his essay, blames the
delay on the botanical industry, claiming that it has "consistently
blocked" such a proposal. An industry spokesman denies the
charge.
"It is untrue," says
John Hathcock, vice president for nutrition and regulatory science
for the Council for Responsible Nutrition, stating it is in the
interests of reputable herbal medicine manufacturers to have recognized
quality standards.
"The industry has asked for
regulations for the past five years, especially in the area of
good manufacturing practices," he says, and he commends the
Netherlands study as being "pretty well-balanced and the
reviews of the studies pretty much on target."
In the Netherlands study, DeSmet
discusses the problems of measuring the quality and efficacy of
herbal medicines as well as insuring their safety in the unregulated
marketplace. He then reviews several dozen studies of four popular
herbs: ginkgo biloba, used to treat dementia; hawthorn, recommended
in cases of heart failure; saw palmetto, used to treat swelling
in the prostate; and St. John's wort, recommended for depression.
He reports that a number of the
studies reported scientifically significant improvements in symptoms
for these illnesses, but criticizes the methodology of many of
the studies as having too few participants, being too short in
duration, failing to use standardized symptom scores to rate results,
or reporting only positive results.
In discussing the data used to
support the use the St. John's wort to treat mild or moderate
depression, for instance, DeSmet points to one review that stated
the rates of response to St. John's wort were 23 percent to 55
percent higher than response rates to a placebo. However, the
authors write, the review identified only one of the randomized,
controlled trials used as a basis for the conclusion as without
methodological flaws, and "even that trial has raised some
questions."
Marcus, who teaches medical students
about alternative medicine by having acupuncturists, herbal medicine
specialists and homeopathic doctors speak in his classes, is personally
skeptical about the benefits of herbal medicines. However, he
believes strongly that doctors need to be informed enough about
herbal medicines and open enough so that their patients will discuss
the subject with them.
"I think the evidence is very
clear that using herbs has considerable potential danger and very
little upside," he says, especially when FDA-approved prescription
drugs are available to treat the same illnesses.
"But doctors do need to inform
themselves about popular therapies so they can provide help to
patients. People aren't asking their doctors about herbal medicines.
They're just taking them," he says, yet it is their doctors
who, in the face of poor regulation, are the ones who can help
patients avoid the pitfalls of poor combinations of drugs and
the dangers of certain herbal products.
What To Do
The American
Academy of Family Physicians and the National
Institutes of Health have helpful fact sheets on what you
should know about the risks of mixing herbal medications with
certain medical conditions. An explanation of the different kinds
of alternative medicine can be found at Alternative
Medicine Foundation Inc.
Reference
Source 101
For more information on how to prevent other diseases, use
PreventDisease.com's "Quick
Prevention Resources".
|