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brymble
June 30th, 2011, 01:40 AM
We have enough comfrey in our yard to heal all the broken bones of both Iraq wars. OK, maybe not quite that much, but definitely a lot of the stuff. Aside from making enough salve to fill the ring for the International Grease Wrestling Championships, and having one hell of a happy compost heap, what else can I do with the stuff? How would I put it in soap? Can the chickens eat it? Can I eat it or not? I've heard conflicting information. On the one hand, I'm told it can cause liver damage, on the other people have eaten it for centuries, some people claim they still eat it now, and only consuming excessive amounts will cause the damage.

Aeon Flux
June 30th, 2011, 02:22 AM
Personally I think that if it's harmful enough that applying it topically on broken skin can cause problems it shouldn't be eaten.

http://www.umm.edu/altmed/articles/comfrey-000234.htm

brymble
June 30th, 2011, 06:03 PM
Actually the reason why it causes problems applying topically to deep wounds is not due to toxicity, but because it causes such rapid surface healing the deeper wound doesn't have time to heal before it's closes. I looked that one up.

Aeon Flux
June 30th, 2011, 08:49 PM
It contains pyrrolizidine alkaloids which can cause death. Applying it to broken skin would also introduce the pyrrolizidine alkaline right into the bloodstream. They even suggest not using too much topical treatments containing comfrey because the pyrrolizidine alkaloids can be absorbed through the skin as well. I, personally would not take that gamble.

Not to mention the fact that the PA levels can differ from plant to plant.

Terra Mater
July 1st, 2011, 12:53 AM
From http://www.hort.purdue.edu/newcrop/afcm/comfrey.html

Prickly comfrey was evaluated for its value as a forage by the USDA and numerous state experiment stations more than 80 years ago. Comtrey yielded less than some common forage crops and its high water content of 85 to 90%, in comparison to 75 to 80% for alfalfa, made forage preservation difficult. The extensive hairs on comfrey leaves restricts its use as a forage. Fresh leaves are eaten by pigs, sheep, and poultry, but are frequently unpalatable to cattle and rabbits. Cattle and rabbits will eat the wilted forage. Horses, goats, chinchillas, and caged birds are also fed this forage. In a grazing trial in St. Paul, MN, comfrey was judged to be poorly palatable in comparison with several other plant species. This is probably due to the presence of hairs which wilting alleviates.


Wild comfrey was brought to America by English immigrants for medicinal uses. The allantoin content of comfrey, especially in the root, has resulted in its use in folk medicine for healing wounds, sores, burns, swollen tissue, and broken bones. Allantoin, found in milk of nursing mothers and the fetal allantois, appeared to affect the rate of cell multiplication. Wounds and burns seemed to heal faster when allantoin was applied due to a possible increase in number of white blood cells. Comfrey has been reported to promote healthy skin with its mucilage content that moisturizes and soothes, while the allantoin promotes cell proliferation.

The allantoin applied to external wounds is either a 0.4% solution or a 2% ointment. An effective allantoin formulation is difficult to prepare from comfrey due to the low and variable content of this substance. Hart (1976) reported that dried comfrey leaves contain 0.1 to 1.6% allantoin while dried roots have 0.4 to 1.5%. Since fresh leaves are 85% water, they could not contain more than 0.2% allantoin. It would require anywhere from 8 oz to 8 lb of dried comfrey leaves per quart of water to produce a 0.4% solution that would be effective.

Comfrey produces large amounts of foliage from late May until hard frosts in October or November. This crop has been used as a salad green and potherb because it was considered a good source of protein and a rare plant-derived source of vitamin B12. Vitamin B12 is produced usually by soil bacteria and fungi or in the small intestines of some animals. Humans usually obtain this vitamin from eggs, dairy products, and meat. However, a study on the nutritional value of comfrey conducted in Australia in 1983 found that you would need to eat more than 4 lb/day of fresh comfrey to obtain the minimum daily requirement of B12. Eating such large amounts of comfrey, a poor source of vitamin B12, is inadvisable due to the potential health hazards.
Protein content of comfrey dry matter (15 to 30%) is about as high as legumes. Robinson (1983) reported specific amino acid and mineral content of comfrey. Hart (1976) mentioned that comfrey has lower amounts of eight amino acids that are essential for humans than turnip greens or spinach, but more than cabbage. Comfrey, like most green vegetables, is deficient in methionine and is also low in phenylalanine. Three ounces of dried turnip greens or spinach, in comparison to 20 oz of dried comfrey, supply adults with the total daily requirement of all essential amino acids, except for methionine. Comfrey also tends to have high ash content.


Hope this helps.

As for Aeon's ideas about comfrey: horseradish can produce both external and internal reactions, but is still a tasty food. Many spicy peppers produce capsaicin, which is topically irritating especially near the eyes and nose, yet those same peppers are a tasty food source. Nettles are prickly to the skin and produce irritation if mishandled, but properly prepared are a tasty food as well and are commonly used to flavor many varieties of Gouda cheese.

Terra Mater
July 1st, 2011, 12:58 AM
From http://www.hort.purdue.edu/newcrop/afcm/comfrey.html

Prickly comfrey was evaluated for its value as a forage by the USDA and numerous state experiment stations more than 80 years ago. Comtrey yielded less than some common forage crops and its high water content of 85 to 90%, in comparison to 75 to 80% for alfalfa, made forage preservation difficult. The extensive hairs on comfrey leaves restricts its use as a forage. Fresh leaves are eaten by pigs, sheep, and poultry, but are frequently unpalatable to cattle and rabbits. Cattle and rabbits will eat the wilted forage. Horses, goats, chinchillas, and caged birds are also fed this forage. In a grazing trial in St. Paul, MN, comfrey was judged to be poorly palatable in comparison with several other plant species. This is probably due to the presence of hairs which wilting alleviates.


Wild comfrey was brought to America by English immigrants for medicinal uses. The allantoin content of comfrey, especially in the root, has resulted in its use in folk medicine for healing wounds, sores, burns, swollen tissue, and broken bones. Allantoin, found in milk of nursing mothers and the fetal allantois, appeared to affect the rate of cell multiplication. Wounds and burns seemed to heal faster when allantoin was applied due to a possible increase in number of white blood cells. Comfrey has been reported to promote healthy skin with its mucilage content that moisturizes and soothes, while the allantoin promotes cell proliferation.

The allantoin applied to external wounds is either a 0.4% solution or a 2% ointment. An effective allantoin formulation is difficult to prepare from comfrey due to the low and variable content of this substance. Hart (1976) reported that dried comfrey leaves contain 0.1 to 1.6% allantoin while dried roots have 0.4 to 1.5%. Since fresh leaves are 85% water, they could not contain more than 0.2% allantoin. It would require anywhere from 8 oz to 8 lb of dried comfrey leaves per quart of water to produce a 0.4% solution that would be effective.

Comfrey produces large amounts of foliage from late May until hard frosts in October or November. This crop has been used as a salad green and potherb because it was considered a good source of protein and a rare plant-derived source of vitamin B12. Vitamin B12 is produced usually by soil bacteria and fungi or in the small intestines of some animals. Humans usually obtain this vitamin from eggs, dairy products, and meat. However, a study on the nutritional value of comfrey conducted in Australia in 1983 found that you would need to eat more than 4 lb/day of fresh comfrey to obtain the minimum daily requirement of B12. Eating such large amounts of comfrey, a poor source of vitamin B12, is inadvisable due to the potential health hazards.
Protein content of comfrey dry matter (15 to 30%) is about as high as legumes. Robinson (1983) reported specific amino acid and mineral content of comfrey. Hart (1976) mentioned that comfrey has lower amounts of eight amino acids that are essential for humans than turnip greens or spinach, but more than cabbage. Comfrey, like most green vegetables, is deficient in methionine and is also low in phenylalanine. Three ounces of dried turnip greens or spinach, in comparison to 20 oz of dried comfrey, supply adults with the total daily requirement of all essential amino acids, except for methionine. Comfrey also tends to have high ash content.


Hope this helps.

As for Aeon's ideas about comfrey: horseradish can produce both external and internal reactions, but is still a tasty food. Many spicy peppers produce capsaicin, which is topically irritating especially near the eyes and nose, yet those same peppers are a tasty food source. Nettles are prickly to the skin and produce irritation if mishandled, but properly prepared are a tasty food as well and are commonly used to flavor many varieties of Gouda cheese.

And as for the pyrrolizidine alkaloids, they are also present in honey, since they are produced in the pollen of the plant and the bees take those pollens to make their honey. They are also found in meats and dairy products from animals who have fed on plants with PAs in them.

Aeon Flux
July 1st, 2011, 03:36 AM
http://www.ncbi.nlm.nih.gov/pubmed/11276298

http://www.fda.gov/Food/DietarySupplements/Alerts/ucm111219.htm

http://www.ncbi.nlm.nih.gov/pubmed/15482618

Main problem is that there is no way of knowing how "low" the levels of PA is in each comfrey leaf without testing them since two leafs can differ extremely much in levels.

Sure, whatever floats your boat, but as I can't see any dire need for you to consume the comfrey I wouldn't do it if I was you. The risks when you don't NEED the herb far outweighs the benefits as far as I am concerned. Eat whatever herbs you like, but be smart about it. If several countries has banned it as a herbal supplement to take internally and doctors suggest to exercise cautiousness with the herb I'd do so. Since you don't know the levels of the PA in the particular comfrey leaves, and unless you know exactly what you're doing with regards to the plant you might want to lay off the ingestion of it. Not all plants are good for you just because they've been used a lot in the past. *shrugs*

Aeon Flux
July 1st, 2011, 03:44 AM
As for Aeon's ideas about comfrey: horseradish can produce both external and internal reactions, but is still a tasty food. Many spicy peppers produce capsaicin, which is topically irritating especially near the eyes and nose, yet those same peppers are a tasty food source. Nettles are prickly to the skin and produce irritation if mishandled, but properly prepared are a tasty food as well and are commonly used to flavor many varieties of Gouda cheese.

And as for the pyrrolizidine alkaloids, they are also present in honey, since they are produced in the pollen of the plant and the bees take those pollens to make their honey. They are also found in meats and dairy products from animals who have fed on plants with PAs in them.

I didn't say anything about the taste of comfrey or anything like that. PA is a dangerous toxin... and if people are feeding dairy and beef cattle plants with PA I think it's an un-clever gamble since it has been known to cause liver problems in cattle. And I don't eat meat, I don't eat much dairy anymore and I rarely eat honey.

*shrugs* But, as I said... whatever floats your boat. Oddly enough I am one of those people who believe that you should be well-informed regarding herbs before you ingest them. That includes taking in all the information and making a judgement call. Many governments have made their ones regarding comfrey in supplements to be ingested internally. I wouldn't eat it, or drink it as a tea... but that's just me.

Terra Mater
July 2nd, 2011, 06:51 PM
The points were:

Topical reactions are not the best guage of whether or not a plant is edible
Many edible plants are dangerous if eaten in ridiculous amounts. Iron, a vitamin necessary for health and obtained from plant sources is also deadly in large amounts.
In simple terms: you are right about comfrey being harmful but over emphasize the level of harm. Part of being well informed is knowing the true severity of a risk.

From the article I quoted above (http://www.hort.purdue.edu/newcrop/afcm/comfrey.html):


The allantoin applied to external wounds is either a 0.4% solution or a 2% ointment. An effective allantoin formulation is difficult to prepare from comfrey due to the low and variable content of this substance. Hart (1976) reported that dried comfrey leaves contain 0.1 to 1.6% allantoin while dried roots have 0.4 to 1.5%. Since fresh leaves are 85% water, they could not contain more than 0.2% allantoin. It would require anywhere from 8 oz to 8 lb of dried comfrey leaves per quart of water to produce a 0.4% solution that would be effective.

There is a difference between using comfrey in a salve, eating cooked or fresh comfrey, and using dried comfrey in dietary supplements. The amount of comfrey you are taking in that powder or pill is equal to at minimum a half pound of comfrey at one time.

While I recommend comfrey as a food source, I do not recommend it as a primary one. A little is good, a lot is very bad.

As with many foods, the harm in comfrey comes from the way it is used and the way it is prepared. The minscule variations between individuals leaves is just not that important when you are adding fresh comfrey into a soup (diluting the amount of PAs, they don't replicate during the cooking process after all) or serving a handful of comfrey in a large tossed salad with a variety of greens and veggies. Those same varations can become vitally important when you are slugging down 500 mg of powdered comfrey ni a single dose.

The damage done by PAs to the liver comes again from excess. The liver can resist the small amounts from eating comfrey fresh or even cooked comfrey and obviously has a harder time when you shove half a pound down your throat in a single pill. The skin can handle a light wash from boiled comfrey leaves which is beneficial and reacts to a salve that is half a pound or more of comfrey reduced to goo.

I am aware the FDA has banned the use of comfrey, but the FDA also bans the use of Ibogaine which is very useful in treating (and in some cases curing) opiate addiction so I have a hard time taking them serious. Your NCBI links are to abstracts, not full articles. The full articles show the same data in greater detail that I describe above.

So you are right that comfrey can be harmful, but so can potato skins if you eat half a pound of them at a single sitting (which was my point).

Aeon Flux
July 2nd, 2011, 10:37 PM
It's not just the FDA that has banned it. The United Kingdom, Australia, Canada, and Germany also have banned the sale of oral products containing comfrey.

I'll just provide you with one more link: http://www.foodstandards.gov.au/_srcfiles/TR2.pdf

Since PA's are present in things like honey and eggs as well as offal it's very hard to know the levels of PA's your taking in when you're eating extra comfrey. Not to mention the liver problems can break out years after your last contact with PA sources. The damage builds up.

As for Ibogaine, it's a psychoactive hallucinogen. They're trying to develop it without the hallucinogen traits. If the FDA allowed it in it's current state, they wouldn't be doing their job. It hasn't even been confirmed to "treat" them. It's just been shown to alleviate opiate withdrawal, which is quite expected. Hard to focus on jonesing on opiates when you're tripping. The research up until recently hasn't even been properly researched, because you can't do proper research when people are tripping off of their heads. I'm sure you'd find that LSD helps alleviate addiction symptoms too (alcoholism), doesn't mean the FDA should allow it off of their heads.

Main thing here is, you can't know how much PA's your getting into your system. The smart thing would be NOT to compound the issues since the adverse effects can take years to become critical enough to manifest. BUT, that being said, if you want to risk it, be my guest. Just because I wouldn't doesn't mean you shouldn't. Your liver is of no concern of mine, but I do want others who read the forum to know both sides of the story, as it were. Both the concerned side and the "just don't eat half a pound of it and you'll be fine" side.

There, I think we've established a nice balance, don't you? :D

ETA: The link from the University Of Maryland Medical Center (http://www.umm.edu/altmed/articles/comfrey-000234.htm) that I put up in the beginning, in case people are too lazy, here is what it had to say:


How to Take It:

Pediatric

Never give a child comfrey by mouth, and do not apply creams or ointments containing comfrey to a child's skin.

Adult

Never take comfrey by mouth. Severe liver poisoning and even death may occur.

Use herb and leaf ointments, creams, and other topical preparations. Toxic alkaloids can be absorbed through the skin so it's important to follow these safety recommendations:

Never apply comfrey to broken skin.
Use only small amounts of comfrey-containing creams for no longer than 10 days at a time.
Do not use any comfrey product for more than 4 - 6 total weeks in a year.
Precautions:

Comfrey contains toxic substances that can cause severe liver damage and possibly even death. For this reason, comfrey and comfrey-containing products should never be taken orally.

Comfrey contains toxic substances that can be absorbed by the skin, so even topical preparations should be used for only a short time under the supervision of a knowledgeable health care provider.

Comfrey should never be applied to open wounds or broken skin.

Do not use comfrey if you have liver disease, alcoholism, or cancer.

Children, the elderly, and pregnant or breastfeeding women should not use comfrey products -- either orally or topically -- under any circumstances.

brymble
July 3rd, 2011, 11:18 AM
Wow. I just remembered what I was missing. Is it possible to answer the simplest of questions on this board without everyone resorting to sniping and bickering? Apparently there is disagreement on this topic. Is it really worth fighting about? Please breathe!

Aeon Flux
July 3rd, 2011, 08:39 PM
I wasn't sniping, or bickering. I thought we were both giving different views on the matter. It's quite normal for people to have different views on things such as herbs, especially herbs such as comfrey. I am much less pleasant when I'm fighting. :D

Twinkle
July 3rd, 2011, 09:36 PM
*shrugs*

Who is fighting? I'm seeing different points of view with linkage to emphasize each opinion. I think it's called a discussion....a discussion that I find fascinating, by the way.

*goes back to reading linkage*