#49 Herbal Healing: Careful With Comfrey

Not just pretty

Comfrey isn’t just a pretty plant. Growing approximately three feet tall and producing stalks covered with pointed leaves and white, pink, or purple flowers, herbal medicine traditions have used applications of this plant for centuries. From poultices or mashed topical treatments of the plant and steeped leaf teas to today’s creams and ointments, the herbal healing power of comfrey applies to pain and inflammation from injury and degeneration.

Many people experiencing neuropathic pain and discomfort, also experience arthritis, myalgia, and sore muscles. Safe preparations of comfrey may provide relief for these symptoms. As simple and natural a remedy like the comfrey plant may seem, before planting, poulticing, purchasing or playing doctor, understanding the safe preparations of comfrey is vital; repercussions can be fatal. Comfrey may be a pretty plant, but its make up is pretty powerful!

Careful – use as a topical only

Historically the entire comfrey plant was utilized in teas and poultices, but the roots were never to be ingested as they are highly toxic. Meanwhile, comfrey leaves and the above ground plant parts, were reliably used for their safe healing benefits. Although some people ingest comfrey in the form of leaf tea to relieve gastric ulcers and other pains, consumption of even the safer parts prove to be risky. Despite the herbal healing traditions of comfrey, studies today determine that the entire plant contains pyrrolizidine alkaloids (PAs), with the highest concentrations in the roots . Existing in most environments, PAs are part of nature, being widespread and copious in plants. Research shows that PAs have connections to liver damage and cancer, due to evidence relating to PAs absorption during consumption. While this may deter some individuals from using any comfrey preparations, research worries focus on ingestion of the plant, with concern for the leaves and definite risk for the roots. Meanwhile, studies show that topical treatments using comfrey leaf, have healing benefits and are safe on a short term basis. Concerns for any oral use are justifiable, causing many countries to restrict medicinal comfrey products.

While more studies on topical products containing PAs need to be conducted, much research on the external use of comfrey preparations for pain, inflammation, and wound healing provides encouraging and reasonable toxicological assessment. These benefits for pain and inflammation are due to the plant being high in the protein allantoin, which encourages cell proliferation, tissue regeneration, and ultimately healing. The positive effects of allantoin, combined with the negative effects of consuming PAs, leads to literature focusing on the topical applications of comfrey, so as to attain benefit without severe health risks. Some pharmacies offer PA free or depleted creams or ointments, allowing for long term usage and pain management.

Ultimately, most comfrey preparations are not for long term use due to PA concerns, as well as the possibilities for adverse interactions with existing prescription drugs and other health conditions. Always consult with your health professional before attempting any new health regimes or topical treatments, as even homegrown medicinal plants are extremely powerful. Furthermore, plants need proper identification. Ensuring you are preparing comfrey safely is important, as well as not confusing a different plant for comfrey. It is easy to mistake foxglove leaves and flowers for comfrey, with foxglove being fatal.

Focusing on external applications of comfrey, many natural remedy users utilize the wound healing benefits, through homemade plant poultice. Comfrey preparations may also be purchased and applied externally encouraging healing of bruises, sprains, and cuts. Topical preparations of comfrey in the form of creams, ointments, and extracts are being studied, with considerations for healing effects on sore muscles and joints, back pain, osteoarthritis, rheumatism, and myalgia. These applications for pain and discomfort are important as many experiencing neuropathy may also experience these conditions as well.

Overall, further research on topical comfrey applications is needed, with oral usage being discouraged and even restricted. It is recommended to stay with the topical form and to check with your healthcare provider if you have questions or concerns.

For more information on topicals also see: #18 Arnica – A Natural Solution to Neuropathy Symptoms, #28 Capsaicin – An Effect Treatment for Neuropathy, #36 Medical Cannabis,  #54 Lidocaine – Numbing the Pain

References

• Balch, P. A. (2002). Prescription for herbal healing. Penguin. Retrieved from https://books.google.ca/books?id=ZuWcxtk0wRQC&lpg=PR6&vq=butcher%252520broom&dq=herbal%20healing%20butcher%20broom&lr&pg=PA51#v=onepage&q=comfrey&f=false
• Foster, S. (2002). COMFREY. Peterson Field Guide To Western Medicinal Plants & Herbs, 199. Retrieved from: http://web.b.ebscohost.com.elibrary.calgarypubliclibrary.com/scirc/pdfviewer/pdfviewer?vid=3&sid=25dcd890-c0f7-4df3-bc12-973e1c2ae2f4%40pdc-v-sessmgr01
• Frost, R., O’Meara, S., & MacPherson, H. (2014). The external use of comfrey: A practitioner survey. Complementary therapies in clinical practice, 20(4), 347-355. Retrieved from: https://www.sciencedirect.com/science/article/pii/S1744388114000437
• Jedlinszki, N., Balázs, B., Csányi, E., & Csupor, D. (2017). Penetration of lycopsamine from a comfrey ointment through human epidermis. Regulatory Toxicology & Pharmacology: RTP, 831-4. doi:10.1016/j.yrtph.2016.11.015 Retrieved from: http://web.a.ebscohost.com.elibrary.calgarypubliclibrary.com/ehost/detail/detail?vid=16&sid=11dad043-b66c-4176-b172-8a4e9569571f%40sessionmgr4007&bdata=JnNpdGU9ZWhvc3QtbGl2ZQ%3d%3d#db=aph&AN=120320330
• Marchettini, P., Lacerenza, M., Mauri, E., & Marangoni, C. (2006). Painful Peripheral Neuropathies. Current Neuropharmacology, 4(3), 175–181. Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2430688/
• Medicinal Herbs: NTP Extracts the Facts. (1999). Environmental Health Perspectives, 107(12), A604. Retrieved from: http://search.ebscohost.com.elibrary.calgarypubliclibrary.com/login.aspx?direct=true&db=aph&AN=3836744&site=ehost-live
• Smith, L.W., Culvenor, C.C.J. (1981). Plant Sources of Hepatotoxic Pyrrolizidine Alkaloids. Journal of Natural Products, 44(2), 129-152. Retrieved from: https://pubs.acs.org/doi/abs/10.1021/np50014a001 8. Staiger, C. (2012). Comfrey: a clinical overview. Phytotherapy Research, 26(10), 1441-1448. Retrieved from: https://onlinelibrary.wiley.com/doi/full/10.1002/ptr.4612