Rosemary Gladstar and Comfrey

[Guest guest]

The Comfrey Controversy by Rosemary Gladstar

Over the past several years I've been increasingly aware of the controversy

surrounding the use of comfrey. At first, I simply ignored it, but recent

articles and current information have prompted me to write a response.

I've witnessed so much controversy over favorite herbs. Usually facts are

misleading and after several years of 'black listing' evidence creeps up

that redeems the deposed herb. Sassafras, one of my favorite tea drinking

herbs, was removed from the market because of the potential toxic effects of

the chemical safrole, (though it's estimated that modern beer is 10 times

more carcinogenic than old fashion sassafras root beers banned by the FDA

for the purported carcinogen, safrole). After thirty years on the herbal

black list, sassafras is in favor again and is showing up in tea blends and

formulas. Pennyroyal has received deplorable press ever since two young

women each drank an ounce of the oil in the 70's and killed themselves.

Cautious use of licorice is recommended because of potential problems with

elevated blood pressure, though most studies indicate that licorice induced

blood pressure is due to concentrated licorice extracts, candy, and syrup,

not the whole root. Even slippery elm is listed as potentially toxic and is

not recommended for internal use. It seems that native women used the soft

inner bark of the elm tree vaginally to induce abortions. With all this

controversy it doesn't surprise me to see comfrey come to 'trial'. But what

does surprise me is the neurosis that herbalists are acquiring over this

comfrey cast. It's enough to give one an ulcer!

Are we getting lost in the backwash of current trends of herbalism that lean

towards science, scientific testing, and professionalism? Are we forgetting

the value of centuries of recorded use? Is human testing conducted over

thousands of years no longer equal to laboratory scientific testing?

Shouldn't 'empirical evidence' at least be considered, and not forgotten in

the rush of scientific studies and latest 'findings'? Perhaps it would be

good to recall the rich historical documentation of comfrey, which seems

largely neglected in the rush to classify it as toxic.

Comfrey's been a favorite herb of most early herbalists and has been written

about for centuries in the famed old herbals. Hildegard of Bingen, famous

visionary, saint and herbalist of the Benedictines, recommended it for

wounds in the 11th century. Paracelsus, Pliny, Gerard, Dioscoriedes, and

Culpepper were all fans of the herb and recommended it highly. If current

information is correct, these famous healers were killing, not healing,

their patients.

It's no wonder comfrey's been extolled as one of the renowned healing herbs

of all times. Its very name, Symphytum, means 'to heal'. Rich concentrations

of Allantoin. a cell proliferant that stimulates the growth of connective

tissue and cartilage make comfrey a specific for broken bones, torn

cartilage, swellings, and bruises. It contains tannin as well as high

concentrations of mucilage in its chemical make-up so is not only soothing

but constrictive and healing for wounds, cuts. and tears. It also contains

steroidal saponins making it particularly beneficial for reproductive and

hormonal imbalances. Along with all its specific healing properties, comfrey

is also a delicious and nourishing food herb. It: contains high amounts of

plant digestible calcium, iron. protein (up to 35%, seven times more protein

than soybeans), B vitamins and vitamin A, among other things.

Down through the ages in many parts of the world comfrey's been recognized

as one of the great healing herbs and has maintained its scrupulous

reputation....right up to the present day. In 1968 an independent Japanese

scientist first reported finding pyrrolizidine alkaloids, substances that

are regarded as potentially hepatoxic and carcinogenic, in the young leaves

and roots of comfrey. Austrian studies confirmed the Japanese reports. The

news spread through the scientific community and filtered into the herbal

community like wild fire. What a furor those reports caused. A recent

headline in one newspaper states " Warning ! Comfrey Tea can Kill You " ! Once

considered one of the great all time healing herbs, comfrey now sits on

trial as a possible carcinogen and as a cause of hepatic veno-occlusive

disease.

Pyrrolizidine alkaloids (PA's), a broad based chemical group including more

than 200 different alkaloids, are found in a widespread variety of flowering

plants throughout the world. They seem to be most concentrated in members of

the Borage family, the Pea family, and some members of the Aster family.

PA's first became a health concern in the mid 70's when, during a severe

drought several thousand Afghani villagers developed severe liver

impairment, many of whom died. The source of the problem was traced to PA

infected wheat (from a Heliotrope species). There have been a couple of

other epidemics of veno-occlusive disease occurring in third world countries

as a result of accidental and long term ingestion of PA infected grain

(traced to Crotalaria species). These cases prompted an investigation of

plants containing PA's. In the process, comfrey, the most popular and widely

used memberof the Borage family, was analyzed. It is difficult to draw any

conclusive information, however, from the tests given the various results

reported. As is so often the case with studies, there are enough

discrepancies and various " scientific findings " to satisfy what ever we'd

like to believe.

Though it is important to be open to the possible dangers of comfrey, it is

as important to sift through the information and misinformation and to form

opinions based on fact, rather than hysteria. The truth of the matter is

that most plants reveal within their chemical blue print a wide variety of

constituents, many of them potentially harmful. These chemicals form a

synergistic relationship with one another, often nullifying and or

strengthening certain aspects of one another. Tierra states in The

Way of Herbs, " Plants have a dynamically complex biochemistry. In many

instances this allows for small amounts of substances, which when isolated

and concentrated might otherwise be poisonous, to be quite safe and

harmless. " The sum total of these hundreds of chemicals determine the

personality, or action of the plant. Judging a plant's action based on one

chemical is like judging a person by the fact that their hair is brown.

Studies conducted in Washington found very minute amounts of pyrrolizidine

alkaloids in comfrey. Some plants tested had none at all. An independent

researcher in the U.S. found that of three samples tested for pyrrolizidine

alkaloids, one was negative, the second contained only trace amounts, and

the third contained one part per million equaling a sum total of an

infinitesimal amount of this alleged toxic substance. In 's

article in the February issue of Herb Companion he cites that 8 PA's have

been identified, though different varieties of Comfrey have various amounts

and only two of the most abundant PA's, according to him, are under

scrutiny. It brings to mind the words of the highly respected Dr. Rudolp

Weiss " Modern methods of chemical analysis are now so sophisticated, working

in nano units (l0 to the 9th power), that harmful substances will be found

almost anywhere, with the result that we feel constantly threatened. " Dr.

Weiss, by the way, seemed cautious about accepting current research on

comfrey toxicity.

It might be discerning while reviewing the PA containing factor of comfrey

to consider the rest of this plant's biochemical characteristics. Comfrey is

rich in allantoin, a cell proliferant, calcium salts, and

mucopolysaccharides, all of which are very nutritious to the cell and may

serve to neutralize the cell inhibiting action of the pyrrolizidine

alkaloids. It is also important to note that the pyrrolizidine alkaloids

found in comfrey are in a " N-oxide " , or organic state, unlike those used in

laboratory studies. These organic compounds are more likely to be degraded

when digested in the human body.

Another important issue to consider is the nature of the tests used to

determine the toxicity factor of comfrey. Once identified, the alkaloids

were isolated and injected into laboratory animals in rather massive

amounts, far more than would normally be ingested. De Sylva states

in The Canadian Journal of Herbalism: " The original research (on the

presence of pyrrolizidine alkaloids in comfrey) was seriously flawed.

The laboratory rats that developed tumors on the liver were only six weeks

old. At this age, quite a number of substances would be inappropriate for

them to ingest. As well, the total amount of comfrey ingested formed 30-50%

of their basic diet. This could be compared to human consumption of several

platefuls of comfrey daily. This daily regimen did eventually cause tumors

to grow on their livers and proved only one of the standing laws of science:

that every substance or chemical is a poison if we consume enough of it. "

Or as Paracelsus said several hundred years ago, " All things are poison and

nothing is without poison. It is the dosage that makes a thing poisonous or

not. " It might be wise to note when observing animal studies that comfrey is

used extensively as a fodder for dairy and beef cattle throughout the

Pacific Northwest with no problems. In fact, farmers are growing fields of

comfrey because of the outstanding results in milk production and the health

of the herds.

Because of these laboratory findings, an attempt was made to collect case

histories of individuals who used comfrey and later developed liver

toxicity. However, of the thousands of people who use comfrey worldwide,

only three somewhat questionable cases have been identified, none of which

conclusively point to comfrey as the culprit. In 1984 there was a case of

veno-occlusive liver disease in a 49 year old woman who had been taking

Comfrey- Pepsin tablets for four months. The American Journal of Medicine

reported a case of a woman who reportedly drank as many as I0 cups of

Comfrey tea a day and handfuls of tablets and developed veno-occlusive liver

disease. The third reported case of veno-occlusive liver disease was that of

a 23 year old New Zealand man who died of liver failure reportedly due to

veno-occlusive liver disease. He was said to have eaten four or five steamed

comfrey leaves every day for one to two weeks before he died.

This appears to constitute the complete 'hard evidence' for condemning

comfrey. Not having access to the complete case histories on these patients

I can make no statement of whether, in fact, comfrey is the only possible

etiologic factor for the liver pathology. Even if it is, three cases out of

tens of thousands, perhaps millions of people who use comfrey is not

statistically significant enough to ban its use. If our pharmaceutical

industry were subject to such standards, we would have no drugs on the

market at all. And very few herbs.

No matter what your position on this matter, this toxicity information

should be put in perspective. Mark Blumenthal states, " The comfrey incident

might have looked different if it I had been put into context of a toxicity

scale. One such scale is the HERP index, which classifies the cancer-causing

potentials of various substances. Extrapolating from the HERP index, former

U.S. Department of Agriculture botanist Duke, Ph.D., calculates that

less than one-fifth an ounce of brown mustard is twice as cancer causing as

comfrey tea, which has roughly the same cancer-causing potential as a peanut

butter sandwich. Wine is 144 times more cancer causing than an equal amount

of comfrey tea. " It is essential to always recall when reading test results

that the whole is always greater than the sum of the parts. As more and more

tests are being conducted on herbs and the chemicals isolated, it is

important to be open minded about the results; open minded to the fact that

science is fallible.

If a plant has been found safe and effective for a thousand years of human

use, it may be wise to question the validity and applicability of the tests

being used. There is generally some unidentified part of the plant in the

form of another chemical or an innate natural wisdom that allows the

medicine, when taken as a whole, to function in a safe and beneficial

manner.

The comfrey controversy continues to rage. Banned in Canada, comfrey awaits

its fate in the U.S. Some herbalists continue to use comfrey basing their

faith on 'the empirical evidence of the ages' and ignoring current data.

Most herbalists are taking a more conservative discerning stand recommending

small amounts of comfrey for internal purposes (awaiting pending

information) and continuing to use it externally. Some herbalists, caught up

in the ferver of the tests, have discontinued its use altogether and

advocate others do so also. As for me, until the evidence and 'hard facts'

are much more compelling, I will continue to use comfrey judiciously for

myself and my clients.

Meanwhile, the Austrian company that conducted the original tests verified

that the tests were inconclusive and in Japan, where the alkaloids were

first discovered, doctors still continue to recommend comfrey for cirrhosis

of the liver. Through its whole " trial " comfrey seems unabashed. It

continues to dauntlessly grow. A large luxurious plant, its carefree

attitude seems to say, " if you doubt my safety, don't use me! I've been

around a long long time. I'll outlast the controversy " .