CAUTIONS ABOUT HERBAL MEDICINE
by Camilla Cracchiolo
There is nothing about herbs that automatically makes them non-toxic just
because they are natural. Ever hear of deadly nightshade or poisonous mushrooms?
They are drugs, like other drugs and should be approached with the same caution.
This means, for example, that pregnant women should be as careful about
medicinal herbs as they are about conventional medicines. Some medicinal herbs
are clearly linked to birth defects. People on certain medications, like anti-
coagulants or psychiatric drugs, can have serious problems from interactions
between the herb and the medicine they’re taking. In the US, herb labels do not
list information about side effects, dangers and contraindications on the label
(which I think they should). Many physicians are not well informed about herbs,
and so you cannot always rely on your doctor to know about potential problems.
And if you have or suspect you have a serious illness, it is very important to
be under a doctor’s care. Self diagnosis is not always accurate and self
treatment doesn’t always work.
I believe it is vital for any person who wishes to try herbs to be very well
read before attempting them. I strongly recommend The Honest Herbal by Varro
Tyler to anyone who is considering or using herbal medicines. It is the one
herb book that I have ever found that relies solely on scientific studies
instead of anecdotes and which provides references. Tyler himself has
impressive credentials, being a tenured professor of pharmacognosy (the branch
of pharmacy that deals with herbal medicine) in the school of pharmacy at Purdue
University. The ISBN # is 1-56024-287-6 and it is published by the Haworth
Press, 10 Alice Street, Binghamton NY 13904-1580. It is in print, costs about
$20 and I got mine through a regular bookstore which special ordered it for me.
I personally regard herbal medicine as useful primarily in two situations:
* when a basically healthy person uses an herbal compound for a short, self
limiting condition such as a cold or the flu, where over-the-counter remedies
would normally be appropriate.
* in the case of serious illness, where no effective standard treatment exists
and where there is some evidence from the scientific literature that a
particular herbal compound may help.
An example of this would be the use of silymarin (an extract from milk thistle)
in the treatment of chronic viral hepatitis. In this kind of situation, I
regard it as extremely important that the person be under the close supervision
of a physician well versed in the disease in question and who has reviewed the
available studies on the herb to be used.
Herbal medicine has some very big problems. The most important is probably that
herbs often have not been subjected to thorough testing. Even when an herb has
many studies published about it, almost always the studies are on animals; human
studies are quite unusual. Studies to determine whether the compound can cause
birth defects are vanishingly rare, as are studies to determine whether the
compound can cause cancer. Relying on traditional folklore is not much help;
very obvious or dramatic adverse effects may be caught this way, but it doesn’t
tell us much about either long term effects or problems caused in only a small
percentage of people.
Another major problem is that the amount of pharmacologically active ingredient
available varies widely from plant to plant, so accurately regulating dosage is
difficult. The pharmacologically active ingredient may also occur in conjunction
with other toxic compounds. Examples of toxic agents often found in herbs
include pyrrolizadine alkaloids (very toxic to the liver and cause both benign
and malignant liver tumors); coumarins (which decrease the ability of the blood
to clot); and allergens. The latter can be quite important to people who are
allergic to ragweed; some herbs in the ragweed family (chamomile and yarrow are
examples) can cause severe allergic reactions in these folks.) Most companies
do not list the source of their herbs or how they were grown. Pesticide
contamination is a possibility and heavy metal contamination of some herbs has
been reported in the scientific literature.
Because of the problems mentioned above, I believe it is often better to rely on
an extracted and standardized compound (conventional drugs) when possible.
However, some of the active ingredients of herbs cannot be found in this form.
Yet another problem is with herb labeling. Very few herbal medicines marketed
in the US have both the Latin name of the herb and an expiration date marked on
the bottle. Often, this is deliberate: fraud is rampant among companies
marketing herbs. One brand that does have good labeling is Nature’s Way.
Alternatively, if you live in a city with a large Chinese, Japanese or Korean
population, you can try the herb sellers in that district. I’ve personally
found the herb sellers in Chinatown here in L.A. to be very honest and
knowledgeable (although language is often a problem, alas. Gotta learn to speak
Chinese one of these days.) 🙂
If you decide, after your research, to try herbal medicines, you may wish to
consult a trained herbalist. Unfortunately, in the US anyone can hang out a
shingle and call themselves an herbalist. Lots of these people have no idea what
they’re doing. I have found practitioners of traditional Chinese medicine to be
the best trained. I don’t accept the model that traditional Chinese
practitioners use to explain the effects of herbs (yin/yang, hot/cold, damp/dry,
etc.). I also have problems with the amount of unsupported anecdotal info mixed
in with scientific studies. But traditional Chinese doctors treat herbs with a
lot of respect and caution. They are well up on the side effects and
And finally, very few herb books contain dosage information. I have a lot of
problems with Michael Tierra’s herb books. I don’t accept the medical models he
endorses (traditional Chinese medicine and Ayurveda). I also don’t like the
fact that Tierra doesn’t distinguish between scientifically validated
information and folklore. But Tierra’s books are among the very few herbal
medicine books that discuss dosage. Just making up a weak tea is usually not
enough to get a pharmacologically effective dose. Tierra is the author of The
Way Of Herbs and Planetary Herbology.
Warning: Tierra’s books should be used as supplemental sources only and never as
your primary source of information on herbs. I have spotted several places
where he has left out important information on toxicity.