Comfrey (Symphytum officiale) is an evergreen perennial with a short, thick stem, large basal leaves with tiny leaf hairs, and a tuberous and extensive root system from the Boraginaceae family. Comfrey is a native plant to Europe and Asia and was originally cultivated in Europe over 2,000 years ago, for its incredible anti-inflammatory, analgesic, and tissue regenerating properties (Stickel and Seitz, 2000). The word “Symphytum” comes from the Greek word, “Syumphuo” which means “to make grow together”. Both the leaves and the roots can be used medicinally, with the most medicinal properties present in the latter. The plant was traditionally used to heal everything from cuts, burns, sores, bruises, to internal ailments such as, broken bones, digestive problems, respiratory illnesses, or internal bleeding. Comfrey traditionally was administered in a large variety of ways. Poultices and salves were common for topical treatments, and tea, mucilage (syrupy tincture with honey and glycerin) or tinctures, were created and administered for internal ailments. Comfrey was introduced to Canada from Europe in the mid 1900’s (Ollman, n.d.). Recently, Comfrey has been regarded in permaculture as the “Dynamic Accumulator”. A perennial, Comfrey has enough time to grow roots deep into the sub soil, to break up compaction and gather nutrients that other plants cannot get, use, or bring to the surface. Their large accumulation of macro and micronutrients means that Comfrey leaves are used to make a compost tea, put on crop beds as mulch, or green manure to jump start compost. Traditionally, their large accumulation of nutrients and large tuberous roots makes them a nutritious food source for humans, but consumption has ceased due to recent discovery of pyrrolizidine alkaloids (PAs). Comfrey is also widely used as a forage crop, with sharp leaf hairs, cut and let wilt to make palatable for animals. Comfrey, with an established root system, can provide numerous cuttings a year making it a very close competitor to other forage crops (Garms, 2016).
Comfrey has had a long and exciting history. It was said to be used to heal the armies of Alexander the Great and was grown in the gardens of Catholic monks. In 1896, in the British Surgical Journal, the Lancet, recorded a case of a man with a malignant tumor growing on his face. He was sent home to die. The man came back three months later completely healed claiming to have put a poultice of Comfrey on his face every day. Though this story is still speculative, there is still countless observations over the last centuries of internal and external healing powers of this medicinal plant. Samuel Thomson wrote about his personal experience of breaking his foot on farm equipment. Later on, the foot abscessed and had to be amputated. Samuel called to his father to gather some Comfrey nearby. After a poultice was applied a miraculous bone healing followed, saving his foot (Ollman n.d.).
Recently, science has understood the pharmacological mechanisms that are present in Comfrey. The basic medicinal chemical compound is based on the presence of allantoin. Allantoin is present in breast milk in humans and created by most other mammals as well as some plant species. Allantoin is responsible for the multiplication of specifically healthy cells. (EFF) Comfreys tannins gives Comfrey its astringent properties that make it ideal for stopping internal hemorrhages. Furthermore, the tannins in the Comfrey also make the plant have antiseptic properties (Ollman n.d.). A study published by Cambridge University states that rosemarinic acid, is likely to mediate the plants anti-inflammatory properties as well as its analgesic and astringent effects (Stickel and Seitz 2000).
Comfrey has a long and exciting history, thought to be one of the first plants in the world to be used medicinally. Comfrey has numerous documented cases of being a miraculous medicinal plant. Recently, when scientists started understanding more about the pharmacological mechanisms in Comfrey they made an interesting discovery. The discovery is the relative abundance of pyrrolizidine alkaloids (PAs). Pyrrolizidine alkaloids are identified in over 6000 plants, in which half of are hepatoxic. PA’s are considered to be tumorigenic, they can cause Veno-occlusive disease, which usually manifests itself as liver diseases such as cancer or failure, but is also susceptible to other organs such as the lungs, pancreas, and kidneys (Sticky and Seitz 2000).
This discovery has led to Germany, Canada, and other countries around the world restricting the growth and consumption of this medicinal herb. The German government recommends no more than 1 mg comfrey daily to limit toxicity to the body and is illegal to cultivate. Brands sold in stores that guarantee to be free of pyrrolizidine alkaloids are recommended, but are still weary against applying to open wounds because the PA’s are more readily available to your body through the skin. Comfrey is still very much legal in the United States and can be cultivated and used medicinally. The variability of pyrrolizidine alkaloids content in various preparations makes it very difficult to judge their toxic potential. Furthermore, the dose-effect relationship is unclear and individual rate of susceptibility is highly diverse (Stickel and Seitz 2000).
There is sufficient evidence pointing to both legitimacies, positive and negative, of this medicinal plant. The historical and cultural uses of this magical healing medicine, are plastered all over the pages of history. Recently, with pharmaceutical diagnoses’, we see a correlation between the magical regenerative power of allantoin and the hepatoxic PA’s in Comfrey. There is a good amount of debate between the scientific community about the potential benefits and risks of consuming this product. An article out of Cambridge University claims that their study does not include the benefits of Comfrey and states that studies showing the efficiency of medicinal herbs and what they claim to heal, is lacking. Thus, there is a far greater number of proven hazardous effects than positive when it comes to the use of Comfrey. Although many more studies are needed to tell us about interactions between our body and different Comfrey alkaloids, the ultimate decision is up to the consumer of this mysterious ancient herb. The one thing all scientists agreed on was Ryan Huxtables advice; avoid taking medication with herbs during pregnancy and while nursing, avoid herbal drugs in infants and children, do not take herbs on a regular basis and in large quantities, and lastly, beware of taking comfrey (Stickel and Seitz 2000).
Much more research needs to be done on the positive, negative and symbiotic way that Comfrey’s medicinal properties works with the body. A large amount of so called “miraculous feets of healing” were recorded with the use of Comfrey in recent history and recognition of death by Comfrey was not common. It seems the allantoin is in symbiosis with a pyrrolizidine alkaloid, and the presence of pyrrolizidine alkaloid may help allantoin penetrate the body and cause either positive or negative mutations and the mechanism for why cells would mutate in a positive way or a negative way is still unknown. The benefits are too vast to avoid. Even many recent studies have shown the tremendous healing powers of Comfrey. The presence of more than 5000 + alkaloids and the presence of flavonoids and tannins all reacting together, plus a human body, is more calculations than we can come up with in this lifetime with our technology. But it is very interesting that this plant was hypothesized to be grown in the Garden of Eden and has been symbiotic with our species since the beginning. Science shows it does heal you and “knit your bones” and science does show us it’ll kill you, what is going on? Magic!
Garms G. 2016. Why you should have comfrey in your garden [Internet] Sedro-Wooleys (WA): Raven’s Roots Naturalist School; [Cited 13 Feb 2017]. Available from http://www.ravensroots.com/blog/comfrey
Ollman J. (n.d.) Comfrey [Internet]. Herbal Legacy; [Cited 13 Feb 2017]. Available from http://herballegacy.org/Ollman_History.html
Stickel F, Seitz HK. 2000. The efficacy and safety of comfrey. Public Health Nutrition [Internet].[Cited 13 Feb 2017];3(4A) 501-508. Available from https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S1368980000000586
Thanks to our friend and collogue Cameron Skinner for allowing us to reproduce this article.