Subject: Toxic effects of herb tea article

From: [email-masked] (Camilla Cracchiolo)
Date: Thu, 3 Nov 1994 04:39:17 GMT

Warning: long post

copyright 1994 by Camilla Cracchiolo, RN.  May be freely reproduced
for non-profit purposes

A while ago, someone (I forget who) posted an abstract from Archives
of Environmental Health on the toxic effects of herbal teas.  The
article was by Paul Ridker of Harvard Medical School, and he looked
at 26 common herbal teas for toxic effects.  It was in the May/June
1987 issue of the journal.  I requested that someone send me a copy
of the full article, and several kind souls responded; notably Bob
Tennent, who put the article in the mail to me right away. (Thanks,
Bob!)  :)   Since I have gotten many requests by e-mail for the
information in Ridker's article, I am posting this summary here.

Dr. Ridker included a chart of common herbs and their adverse
effects.  I have adapted it at the end of this article.  The
effects of some of these herbs are well publicized.  Datura species
(jimson weed and thornapple) are well known as dangerous.  Health
professionals will recognize foxglove and rauwolfia (snakeroot),
since basic pharmacology classes usually mention that digitalis was
first synthesized from foxglove and reserpine (a powerful anti-hypertensive
and anti-adrenergic agent) from rauwolfia.  Immunologists will
recognize poke weed as a powerful stimulator of immune reactions,
since poke weed mitogen is commonly used in certain tests of
cellular immune function.

However, I was surprised to find hops and burdock root on the list.
Other herbs that are commonly regarded as safe, but which have
reports of serious adverse effects, include chamomile and comfrey.

He lists the main toxic agents in herbal teas as toxic alkaloids,
cardiac glycosides, potential carcinogens, natural coumarins,
monoamine oxidase inhibitors, anthraquinone cathartics, and cholinergic
and adrenergic mediators.  He catagorizes the illnesses associated
with herbal teas as either hematologic, gastrointestinal, nervous
system toxicity or allergic reactions.

HEMATOLOGIC REACTIONS:

Under hematologic reactions, the main culprits are natural
coumarins.  Health professionals and the families of people who have
had thromoembolisms will recognize coumarin as a commonly prescribed
'blood thinning' agent, which lengthens the time needed for blood to clot.
People who chronically consume teas containing coumarins may be
prone to bleeding problems.  He also lists a case of acute limited
intravascular hemolysis (blood cell destruction) following ingestion
of an herbal tea prepared from hops.  Red blood cells incubated with
the tea "were found to have a defect similar to cells from patients
with paroxysmal nocturnal hemoglobinuria (PNH)."  The Merck Medical
Manual, 16th edition, lists the following information for PNH in its
section on hematology and oncology:

Symptoms include: "abdominal and lumbar pain ....  with
splenomegaly, hemoglobinemia, hemoglobinuria (hemoglobin in the
urine -- ed.) and symptoms of severe normocytic-normochromic anemia.
Protracted urinary hemoglobin loss may result in iron deficiency
even though some organs, particularly the kidneys, may be saturated
with hemosiderin.  Leukopenia (low levels of white blood cells) and
thrombocytopenia (low levels of cells key to blood clotting) are
common.  Gross (visible to the naked eye) hemoglobinuria is common
during crises, and the urine may contain hemosiderin.  Affected
patients are strongely presiposed to both venous and arterial
thrombi, a common cause of death."  Ridker doesn't specify whether
symptoms of the full syndrome are present or not; however, this is
obviously a very serious problem and people who are taking hops who
have these symptoms should immediately consult a physician.

NERVOUS SYSTEM TOXICITY:

Ridker divides nervous system reactions into reactions of the
sympathetic nervous system (the part of the nervous system
controlled by adrenalin) and central nervous system (CNS).  One of
the things he neglects to mention about herbs that contain monoamine
oxidase inhibitors is that these compounds are among the more
dangerous of antidepressant medications.  If a person consumes an
MAO inhibitor with foods containing tyramine or with certain other
medications, potentially fatal rises in blood pressure can occur.
In a recent discussion in sci.med.pharmacy, we were concerned about
the use of MAOI containing herbs; if a person is taking these herbs
I feel it is wise to observe all the standard MAOI dietary and other
precautions at a minimum.

Ridker also mentions that 'common tea' (Camellia sinensis), which
I interpret to mean 'black tea', has been associated with side
effects related to its caffeine content: increased irritability,
tremor, premature ventricular beats and acute hypertension.  

CARDIAC TOXICITY:

Ridker mentions under the cardiac toxicity section that there
have been deaths associated with herbs containing cardiac glycosides
when these were mistaken for other herbs.  An elderly couple in
Seattle, Washington died after confusing foxglove for comfrey and
another man died when he confused oleander for eucalyptus.
He also mentions that herbs have been reported as contaminated with
lead, cadmium, mercury, copper, zinc and fluoride.  However, no
clinical reactions to these contaminants have been reported in the
literature. (at least as of the date of publication of Ridker's
article. -- ed.)  There has been one case reported where chronic
arsenic poisoning was suspected in one person consuming herbal tea.

GASTROINTESTINAL REACTIONS:

Under gastrointestinal reactions he mentions that gastroenteritis,
bloody diarrhea and severe hypotension were reported in one patient
following a single cup of poke root.  He also mentions that one
death has been associated with senna, when a person was overseas and
medical intervention was unavailable.

This section also deals with reports of hepatic veno-occlusive
disease.  Since laypeople may not be familiar with veno-occlusive
liver disease (VOD), I quote the following section from "How Much Comfrey
Is Safe?" by Jay D. Mann:

 "VOD is characterised by a blockage of the smallest passages
 (venules) in the liver. Cirrhosis is a general term "applied
 to diffuse liver damage of multiple aetiology" (causation).
 VOD is, thus, a form of cirrhosis but has a unique set of
 diagnostic attributes. The most common cause of VOD is
 poisoning from PA's. In addition, cancer chemotherapy and
 radiation therapy can cause VOD.  An exceedingly uncommon
 cause is use of oral contraceptives.  In non-cancer patients,
 a diagnosis of VOD automatically leads to a search for dietary
 factors.
 
 The symptoms of VOD are a greatly swollen belly (ascites)
 caused by accumulation of ascitic fluid.  In one case, a
 49-year-old woman lost 16 lb when the fluid was drained by an
 operation (Ridker et al 1984).  A Chinese womea  in Hong Kongwho
 died from PA had 3 liters of ascitic fluid at autopsy (Kumana
 et al 1985). A 38-day-old infant had 500 ml of yellow ascitic
 fluid in his abdomen (Roulet et al 1988).
 
 Typical medical findings (McLean 1974) are of a child with
 abdominal pain, or discomfort and distension, large hard liver
 and a large spleen, severe ascites (liquid in the belly).
 Examination of the liver in VOD shows that small vessels have
 been blocked by growth of fibrous tissue, that is, something
 like scar tissue. The distribution of this blockage is
 characteristic of VOD compared to other liver diseases. There
 can be portal hypertension (high blood pressure in the blood
 vessels feeding the liver) because flow of blood through the
 liver has been blocked."

THE HERB CHART:

Herb         Latin Name      Suspected toxin     Clinical toxicity
-------------------------------------------------------------------

Buckthorn    Hiptothae       anthraquinones    Cathartic toxin, severe
               rhamnoides                        watery diarrhea

Burdock      Arctium minus   atropine          anticholinergic
  root                                           blockade

Chamomile     Chamomilla     antigens of the    anaphylactic shock
                reculta        Compositae       contact dermatitis
                               family            (in patients
              Chamaemelum                        sensitive to
                nobile                           ragweed, asters and
                                                 chyrsanthemum)

Comfrey       Symphytum       pyrrolizidine     hepatic failure
               officinale       alkaloids       ?hepatocarcinogen
                                                veno-occlusive
                                                  disease

Foxglove tea  Digitalis       digitalis         malignant arrythmias
               purpurea                         cardiac arrest

Gordolobo     Senecio         pyrrolizidine     veno-occlusive
Groundsel     longilobus        alkaloids         disease
              S. vulgaris                       hepatic failure
              S. spartoides

Hops          Humulus lupulus  ?lupuline        ?intravascular
                                                  hemolysis
                                                ?PNH-like defect

Jimson tea    Datura           atropine         anticholinergic
               stramonium      scopolomine        blockade
                               hyoscyamine      CNS intoxication,
                               stramonium       blurred vision,
                                                ataxia, hallucin-
                                                ations

Kavakava tea  Piper            methysticin     CNS intoxication,
               methysticum                       ataxia, deafness,
                                                 skin yellowing,
                                                 dermatosis

Lobelia       Lobelia inflata  lobeline        anticholinergic
                               atropine          blockade
                               scopolomine
                               pyrridine       ?potential
                                 alkaloids       hepatotoxin

Mandrake      Mandragon        scopolomine     anticholinergic
               officinarum     hyoscyamine       blockade

Mate          Ilex             ?pyrrolizidine  ?veno-occlusive
               paraguaynensis     alkaloids      disease
                                               ?hepatic failure

Melilot       Meliotus         coumarin        hemorrhagic diathesis
               officianalis                    prolonged prothrombin
                                                 time

Mormon tea    Ephedra          ephedrine       sympathomimetic
               nevadensis                        overdose

Nutmeg tea    Myristica        monoamine       CNS intoxication,
               fragrens          oxidase       hallucinations,
                                 inhibitors    visual disturbances
                               myristicin      ?hepatic damage

Oleander      Nerium oleander  cardiac glyco-  malignant arrhythmias
                                 sides: digi-  cardiac arrest
                                 toxigenin,
                                 nerioside,
                                 oleandroside

Poke root     Phytolacca       saponins        gastroenteritis,
               americana       poke weed       bloody diarrhea,
              Plytolacca          mitogens     ?mitogenic
               decandra                           alterations

Sassafras     Sassafras        safrole         hepatocarcinogen
               albidum

Senna         Cassia           anthraquinones  cathartic toxin
               acutifolia                      severe watery
              Cassia                              diarrhea
               angustifolia

Snakeroot     Rauwolfia        reserpine       potential CNS
                serpentina                        intoxication

Tansy         Senecio jacobea  pyrrolizidine   ?hepatic failure
  ragwort                        alkaloids

Thornapple    Datura species   atropine        anticholinergic
                               scopolomine        blockade
                               hyoscyamine

Tonka bean    Dipteryx         coumarin        prolonged pro-
               odoratum                           thrombin time
              Coumarouna                       hemorrhagic diathesis
               oppositiofilia

T'u-san-chi   Gynura segetum   pyrrolizidine   veno-occlusive
                                  alkaloids       disease
                                               hepatic failure

Woodruff      Galium odoratum  coumarin        hemorrhagic diathesis
                                               prolonged prothrombin
                                                  time

Yohimbe bark  Corynanthe       yohimbine       alpha-2
               yohimbe                          (pre-synaptic)
                                                sympathetic blockade

--

-----------------------------------------------------------------------
 Camilla Cracchiolo, RN     [email-masked]    Los Angeles, CA

     Shrine of the Cybernetic Madonna BBS      213-766-1356
              "The BBS for the information addict!"
-----------------------------------------------------------------------

---

From: [email-masked] (Camilla Cracchiolo)
Date: Thu, 3 Nov 1994 18:38:06 GMT

Vicki Finkenstadt ([email-masked]) wrote:
: <nice summary deleted>

: I didn't see a dosage requirement, though?
: Is one cup per day for 1 month enough or does one need a massive
: OD to have these effects?  
: Oh, that sounded bad, didn't it?
: My questions are: Is occasional use of herbel teas okay? Are the effects
: cumulative? Are people safe drinking a cup now and then?
: Thanks,
: V

Like with drugs, it depends on the herb.  There are many herbs used
in the herb teas available in the supermarket that aren't going to
hurt you: peppermint, for example.  On the other hand, some herb
teas in that section contain compounds that can potentially produce
reactions:  chamomile and comfrey; also some herb teas contain blackberry
leaves, which contain coumarins.

Pregnant women should probably avoid all herb teas like they
would avoid drugs.  BTW, pregnant women should also avoid
coffee and other caffeine containing compounds.  People don't
often think of coffee as a medicinal herb, but in fact it
is a pharmacologically active plant agent, and has been linked
to birth defects.  Also, infants and small children are much
more sensitive to the effects of certain herbs.

Some resources:

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 anecdotes.  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_.

One other thing:

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.

Another book which I have been told contains scientific references,
but which I have not read myself, is the _Encyclopedia of Natural
Medicine_ by Michael Murray and Joseph Pizzorno.  It's available
>from  Prima Publishing, P.O. Box 1260MP, Rocklin, California 95677.
The phone # is (916) 786-0426 and the price is $18.95.

A couple of other recommendations were sent to me by Jay Mann in New
Zealand:

"CRC Handbook of Medicinal Herbs",written by James A Duke, published 1985.
Dr Duke was Chief of Medicinal Plant Resources Lab, USDA for 25 years.  The
book covers 365 medicinal plants, one for every day of the year. The "CRC"
label on the cover ensures that the book will be thorough and exceedingly
expensive to buy.  There are nearly 700 largesize pages.

A nice feature is having a sketch of each plant.  At the back is a 7-page
summary of each herb, toxicity score, scientific and common names, and
estimated market price.  The toxicity scores are given in triplets: Duke's
own, Rose's, and Tyler's, (I don't know Rose's.)  He admits that his
scoring is ad hoc, all based on comparison with a cup of coffee!  3=safer
than coffee and wouldn't hesitate to drink 3 cups a day.  (He wouldn't
drink anything more than 3x /day.)  2=same as coffee, 2 cups.  1=more
dangerous, would accept 1 cup a day containing 10 g of steeped herb. 
0=very dangerous, wouldn't drink anything.   He considers himself less
conservative than Tyler, more conservative than Rose.  The book, b the way,
also has proper scientific citations."

According to Jay, this book is quite expensive, but may be available
in some university libraries.

and

"Herbal Remedies: Harmful and beneficial effects", by S Talalaj
& A S Czechowicz.   Publisher is
             Hill of Content Publishing Pty Ltd
             86 Bourke Street
             Melbourne 3000
             AUSTRALIA

I don't have a fax number for them, nor a price, but from memory it cost
only something like $A20 in paperback form.  They were happy to accept a
VISA-card number.