Water01 - Thank you for that great post AND for this opportunity to set the record straight about one of Nature's/God's GREATEST healing plants!

That 'warning letter' was sent to virtually every company that was selling herbs at that time (of which the FDA was aware).  What is most frustratingly (to me) is that one of the LARGEST companies with the most money to fight the lies (Dr. Christopher's company, now run by his children), willingly chose to kowtow and remove the Comfrey from all their father's products, rather than fight the FDA.  So, with one of the major players 'knocked out of the fight', the smaller players (armed with truth & integrity, but very little money), had to shoulder the burden of the battle.  And battle they did, and they WON (even if the court costs for them were astronomical with no way to recoup them).  Herbalists ARE still allowed to include comfrey in products for internal use legally.

The unneccesary "warning" (regarding comfrey only being safe for external use) is still widely in place...which is VERY frustrating.  It is very rare to find someone familiar enough with herbs & natural health/healing that they are not 'scared away' by a "liver damage" & "cancer" warning...so likely millions of people that could benefit from the healing miracles of comfrey are deprived.  :( And this is all very similar to the authorities manipulation of the public concept of the safety of natural Ephedra (not the varieties of sythetic kinds or the products that were mixed with other unsafe plants or chemical stimulants).  The "scare" about Ephedra even 'got me' for a time.   (Note - it's a true shame we don't have a legitimate organization that will test and oversee the marketing of herbal products.  There were truly innocent people hurt very seriously by the use of Ephedra products that were adulterated with chemical toxins.  And there have been cases of people having all kinds of abnormal reactions and problems from taking herbs that were grown with the usage of DDT and other incredibly toxic chemicals.  Besides being a carcinogen, DDT is also a neurotoxin, so there have been people with neurological illnesses that have worsened after taking the very herbs that should help them heal.  :(

When I was researching the FDA/Comfrey/Christopher situation, I found (what appears to be) the "final word on Comfrey" from the FDA's website.  It is pasted below in it's entirely (as written), and then there's "my review" of the data AFTER running it through my "Spin Detector"  (this document puts a theme park ride to shame with the velocity of spin it contains!).

Let's see how good YOUR "Spin Detector" is!  Read the document below and discern what you determine & conclude after reading it.  After you've finished, ask yourself:  Does it provide factual evidence?  Is it legitimate?  After reading it, does the use of Comfrey concern you? What do you now know about Comfrey that you didn't know before?

Here it is, straight from the mouth of the FDA:

The use of comfrey in dietary supplements is a serious concern to FDA. These plants contain pyrrolizidine alkaloids, substances which are firmly established to be hepatotoxins in animals. Reports in the scientific literature clearly associate oral exposure of comfrey and pyrrolizidine alkaloids with the occurrence of veno-occlusive disease (VOD) in animals. Moreover, outbreaks of hepatic VOD have been reported in other countries over the years and the toxicity of these substances in humans is generally accepted. The use of products containing comfrey has also been implicated in serious adverse incidents over the years in the United States and elsewhere. However, while information is generally lacking to establish a cause-effect relationship between comfrey ingestion and observed adverse effects humans, the adverse effects that have been seen are entirely consistent with the known effects of comfrey ingestion that have been described in the scientific literature. The pyrrolizidine alkaloids that are present in comfrey, in addition to being potent hepatotoxins, have also been shown to be toxic to other tissues as well. There is also evidence that implicates these substances as carcinogens. Taken together, the clear evidence of an association between oral exposure to pyrrolizidine alkaloids and serious adverse health effects and the lack of any valid scientific data that would enable the agency to determine whether there is an exposure, if any, that would present no harm to consumers, indicates that this substance should not be used as an ingredient in dietary supplements.

So now, how ya feelin' about the internal use of Comfrey?  Do you feel like you're heard and absorbed the truth?  Before you read the "Sarcastic Spin Detector" version below, there's two things you need to know (or remember).

#1  There are pyrrolizzidine alkaloids present in MANY plants, and many are known to cause liver damage, but so far, there is absolutely zero factual evidence that the specific pyrrolizzidine alkaloids in Comfrey have ever caused liver damage or cancer.   Here are a few of the plants with PAs that have caused damage: http://lib.bioinfo.pl/pmid:7311596  

The inset text below is from this FANTASTIC article of the safey & use of Comfrey: http://www.herbsarespecial.com.au/free-herb-information/comfrey.html

Outbreaks of PA poisoning in humans, in the past, have usually been the result of accidental contamination of food crops, with the toxic seeds of other plants. One such instance was an outbreak of veno-occlusive disease in Afghanistan in 1974. This outbreak followed a severe drought and the people were suffering from acute malnutrition (an important factor). About 22% of the people showed evidence of liver disease when examined in 1975. The cause of the outbreak was traced to bread, contaminated by heliotropium seed (which grew extensively in the wheat fields). Samples of the wheat examined, were found to contain an average of 40 seeds (300 mg) per kg of wheat.

Cases of liver damage, due to people drinking bush teas of seneca and crotalaria, have been reported from a number of places. J. A. Pembery, B.Sc., advisor to the Henry Doubleday Research Association, Essex, U.K. says, in the book ‘The Safety of Comfrey’, that there appear to be no cases, in medical history or veterinary records, of humans or animals, showing clinical symptoms, of pyrrolizidine alkaloid poisoning, from the consumption of comfrey. Lawrence D. Hills, in his forward in the book, mentions that the Commonwealth Bureau of Animal Health very kindly carried out a computer search through their records of 137,000 cases of stock poisoning by plants, since 1972, and found only one concerning case: a case of comfrey-nitrate poisoning in pigs from excessive use of fertilisers in Germany.

#2  At some time in school (likely a long time ago in a science class far, far, away), you probably heard the very valid statement that "correlation does not prove causation" (or "association does not prove causation").   This means, that's just because two things happen to be correlated or associated, it doesn't prove that one causes the other.   For example, it may be true that almost always when you're trying to take a relaxing soak in the tub, the phone starts ringing or the kids go ballistic.  (That's a correlation or an association).  But running a bath full of hot water and getting in it does not CAUSE a phone to ring (or children to misbehave).  Hence, correlation/association does not prove causation (although it's possible that when things are correlated or associated, one of them does cause another).  But two events happening together does not PROVE one causes the other.  One has to do more testing and studying to find out how the events are related.

So, here it is - The Comfrey Bomb (FDA in black - me in cool blue :)

The use of comfrey in dietary supplements is a serious concern to FDA.  

Perhaps you, the FDA would care to be seriously concerned about the 50,000+ deaths from the drug you approved named Vioxx - or the fact that even without including that drug in the number, more than 100,000-150,000 people actually DIE each year from ingesting, as prescribed, the drugs that you've tested and approved.  And before you start researching the dangers of a plant that have been proven to be safe for decades, perhaps you'd like to start dealing with the fact that you allow chemical additives in our food that have already been thoroughly tested and proved to cause cancer and other diseases.

These plants contain pyrrolizidine alkaloids, substances which are firmly established to be hepatotoxins in animals.

Yes, some of the various pyrrolizidine alkaloids in some plants have been shown to be hepatoxic in animals.  But there has NEVER been a verified instance of anyone using Comfrey and developing liver disease because of it.  So what you likely meant to say is: "Some plants contain pyrrolizidine alkaloids that are firmly established to be hepatotoxins in animals (and humans)...but that has never been established with Comfrey". 

Reports in the scientific literature clearly associate oral exposure of comfrey and pyrrolizidine alkaloids with the occurrence of veno-occlusive disease (VOD) in animals.

Yes, there are reports that associate oral exposure to comfrey with VOD, but there are none that prove it...or you (the great and almighty FDA) would definitely be mentioning it.  And 'association' is a LONG way from causation...and barely worth mentioning to a critically thinking scientist without other evidence or conclusive studies.  Do you HAVE any conclusive studies?

Moreover, outbreaks of hepatic VOD have been reported in other countries over the years...

Well, yes, VOD has many causes...what does that have to do with Comfrey?

...and the toxicity of these substances in humans is generally accepted.

There's absolutely no doubt that some pyrrolizidine alkaloids, and virtually all of those extracted/isolated and injected in large amounts, or synthesized pyrrolizidine alkaloids that are typically use for testing,  are toxic at high levels.  So yes, that is "generally accepted" as you say...but you still haven't proven that the specific pyrrolizidine alkaloids in Comfrey are hepatotoxic in any way (even though you continue to strongly imply that).  And just because you're giving us a major "spin treatment" doesn't mean we're dull enough to fall for it. 

The use of products containing comfrey has also been implicated in serious adverse incidents over the years in the United States and elsewhere.

Ahem, taking a bath daily and getting fresh air was implicated as the cause of many diseases and 'adverse incidents' throughout the world for centuries.  The 'fact' that the earth was flat and the oceans had sea monsters was implicated in the 'adverse incidents' of ships for centuries.   Those turned out to be incorrect implications.

Besides"implicated" is a far cry from "proven".  And if you happen to have some "implication" other than heresay or gossip, we'd like to know.   Please tell us what else was in those 'products that contained comfrey'; and were those products -and that comfrey in them- grown in third world countries and doused with DDT and other hepatotoxic pesticides?  And forgive us for questioning you, but just because "you say" Comfrey has been 'implicated in serious adverse incidents', that doesn't make it true --unless you have evidence, of course.  Do you have any evidence?  Can we just stick to the facts please? 

Drumroll please, from THE mouth of the FDA!   However, while information is generally lacking to establish a cause-effect relationship between comfrey ingestion and observed adverse effects humans... well, gosh-golly-gee, you're the FDA, I'm sure you would know if there's any evidence to be found.  And since you admit "information is lacking to establish a true cause-effect",  then, uh, there's no information to establish one, eh?)

...the adverse effects that have been seen are entirely consistent with the known effects of comfrey ingestion that have been described in the scientific literature.  HUH????  You just said there's no information to establish a cause-effect relationship...so how can there even BE adverse effects with known comfrey ingestion, if there's no information to establish a cause-effect???  We're not quite as dumb as you think we are, are you're certainly not as "smooth" as you think you are!  (Did you really just put two totally conflicting statements in the same sentence?)

The pyrrolizidine alkaloids that are present in comfrey, in addition to being potent hepatotoxins, have also been shown to be toxic to other tissues as well.   No! No! No!  You just said that information is generally lacking to establish a cause-effect with Comfrey and adverse effects in humans...and you've NEVER proven or referenced a study that proves Comfrey is a potent hepatotoxin.   What you probably MEANT to say, is that some pyrrolizidine alkaloids from some plants are potent hepatotoxins...and you'd like to lump Comfrey in with those, but you'd don't have any evidence to do so.  So you're lumping it all together anyway and hoping we'll fall for it.  

There is also evidence that implicates these substances as carcinogens.  Implicated? or PROVEN?  And by 'these substances', do you mean synthetic or extracted/isolated pyrrolizidine alkaloids from the known toxic alkaloids/plants, or from the 'Comfrey substances' which you've already clearly admitted have no proven cause-effect relationship to adverse effects in humans? 

Taken together, the clear evidence of an association between oral exposure to pyrrolizidine alkaloids and serious adverse health effects...  Again, as we learned in science class: "association" or "correlation" does NOT prove "causation".   And again-again :::sigh::: are we talking the PA's from the plants that are KNOWN to contain toxic PA's, or the PA's from Comfrey (that have NEVER been proven to cause ANY harm to man or beast)?

...and the lack of any valid scientific data  that would enable the agency to determine whether there is an exposure, if any, that would present no harm to consumers, ...   So far you've got "association" -which you're quite aware, means absolutely nothing unless you have valid scientific data that PROVES a correlation.   AND you have "lack of any valid scientific data".  So exactly what are you going to conclude?

  ...indicates that this substance should not be used as an ingredient in dietary supplements. 

:::in my best Mr. Rodgers voice:::  Okay folks, can you say "AGENDA"???  Sure, I knew you could.

Now then, it is any wonder, that after almost a century of this level of "spin & lies" being imbedded into the minds of society and physicians (AND alternative & natural healers), that we're all scared to death to eat plants to heal ourself?    (Of course, this doesn't mean that we should be stupid and run out there and stuff our face with anything and everything just because it's "natural" and someone said it was good for us).  But it is VERY important to know the the pharmaceutical industry-owned AMA  (whose foundational mission is "to protect the legal & financial interest of it's members") and all it's greedy tentacles, have spent BILLIONS of dollars since the late 1890's,,,,hiring the TOP psychologists and advertising PR experts to propagandize & brainwash society and destroy the competition.  And you just saw one little blurb that's part of the process.  All of us (and all of those we ever try to help) are victims of this 'fear & quackery' campaign...and how deceitful, impactful, and health-destroying their incredible levels of "spin" really are.

Let truth and freedom REIGN!

Unyquity

"Those who know the least obey the best."--George Farquhar