HERB - Re: Herbal Cold & Flu Care

Gaylin Walli gwalli at infoengine.com
Fri Jan 29 09:46:31 PST 1999

Julie wrote:
>I drink an immune tea, which is a mixture of:Echinacea,Nettles,
>Coltsfoot, Comfrey, Red Clover, Alfalfa, Peppermint, and Stevia.

When I finally made it home last night (1 am, feh) I went and
looked up the Comfrey information that I was remembering from
an old Herb Companion article. It was more than a few years ago.
1992, to be exact. Here is a summary of the information on
Comfrey that the article discussed.-- Jasmine, jasmine at infoengine.com

[From "Comfrey: A Fading Romance" by Steven Foster in the Feb/Mar
1992 issue of The Herb Companion, pp. 50-54, typos are my fault]

"....The romance with comfrey began to sour late in the 1970s, when
some reports appeared suggesting that ingestion of the herb was
dangerous. At first, people wouldn't accept this finding. Some
called it the establishment's conspiracy to denigrate comfrey....
Rat's weren't humans, and laboratories were irrelevant to the
success that many had experienced with comfrey....
     In the late 1960s and early 1970s, several research chemists
report on the presence of pyrrolizidine alkaloids (PAs) in several
species of comfrey....PAs became a health concern in the mid-
1970s. During a two-year drought in Afghanistan, more than 7000
Afghani villagers developed severe liver impairment, and many of
them died. Their illness was traced to the ingestion of wheat
contaminated with seeds of a PA-containing heliotrope (Heliotropium)
species. Then, about 70 people in central India suffered severe
liver damage (and nearly half of them died) when food cereals
became contaminated with the PA-containing seeds of the Crotolaria
[pea family] species.
     These reports, couple with an increased understanding of PA
toxicity, prompted scientists and public health officials worldwide
to examine human consumption of PA-contianing plant species more
     Ingestion of PAs can produce venocclusive disease of the liver,
in which the blood flow from the liver is shut off....Comfrey's
safety was questioned directly in a 1978 report on the 'carcinogenicity
activity of Symphytum officinale [common comfrey]' published in
the Journal of the National Cancer Institute. In this study, rats
were fed diets containing from 0.5 to 8 percent comfrey leaf or root
for 600 days. Liver toxicity was observed within 180 days, and liver
tumours developed in all groups. Urinary bladder tumours were also
observed at the lowest dosage levels. The incidence of liver tumours
was higher in rats fed comfrey root than those fed only the leaves
....No cases of human cnacer are known to have been caused by
ingestion of PA-containing plants. But the cancer question is probably
moot because byt the time a person consumes enough PAs to develop
liver cancer, he or she may well have succumbed to other forms of
liver disease....If you use comfrey at all, you should do so only
for short periods of time."

If anyone wants a dead-tree version (photocopy) I'll be happy to mail the
entire article to you. Better yet, if I can scan it in, I'll try to turn it
into a PDF and mail it e-mail to anyone who can receive an attached file.
Go to http://lists.ansteorra.org/lists.html to perform mailing list tasks.

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