Alternative Medicine Debate: Comfrey

Recently I met a woman at my local farmers market who was in search of comfrey. When I discovered that she wanted it to make a tea to drink daily for intestinal problems, I was appalled. I told her that this herb was not guaranteed safe; however, she assured me that her "herbalist" (a term that I will, in this case, use loosely) assured her that comfrey was perfectly safe and even drank quite a lot every day herself. Despite what this woman and her "herbalist" might think, comfrey is not an herb to be used indiscriminately.

Comfrey (Symphytum officinale) was used as a medicinal herb as far back as 400 B.C. by the ancient Greeks, who used it to treat heavy bleeding and bronchial ailments. The first century Greek physician Dioscorides used comfrey to treat wounds and broken bones. (This accounts for the Latin name Symphytum, which is from the Greek word sympho meaning "growing together," while the common name is from the Latin word confervia meaning to heal or "boil together.") The gardener and botanist John Gerard wrote during the Elizabethton era that a salve made from fresh comfrey would "promote the healing of bruised and broken parts." [The Herball, 1597.] Comfrey was also used to treat various internal ailments, such as stomach disorders and diarrhea. In addition, Henry Doubleday was prompted by the Irish potato famine of the 1840s to establish the Henry Doubleday Association, a charitable foundation dedicated to research on the uses and cultivation of comfrey. Around 1910, it was then learned that comfrey contained a substance known as allantoin that can promote bone and tissue healing. However, a real setback occurred in 1978, when it was determined that comfrey also contains pyrrolizidine alkaloids. Studies conducted by the Australians and Japanese showed that rats fed dried comfrey leaves would develop liver cancer within about six months. Additional studies showed that regular use could also cause chronic liver damage. As a result, the United States Food and Drug Administration required in July 2001 that all oral products containing comfrey be removed from the market. The United States joined such countries as Australia, New Zealand, Canada, and Germany in banning the oral use of comfrey.

The use of comfrey externally is still extolled by many, with some justification. The substance allantoin previously mentioned is found in mother's milk and in a tube-like sac called the fetal allantois that becomes part of the placenta. This substance affects the multiplication of cells and the growth of tissue. Yes, wounds do heal quicker when an ointment of comfrey is applied. In addition, comfrey has been used to treat athlete's foot, burns, insect bites, eczema, psoriasis, and other skin irritations. However, there are also warnings concerning the external use of comfrey and any products containing comfrey.

According to the University of Maryland Medical Center, comfrey can be absorbed through the skin and can build up in the system over time. It is recommended that lotions or ointments containing comfrey not be used by adults over extended periods of time; i.e., no longer than 10 days at a time and no more than 4-6 weeks total in a year. Even under these conditions, products containing comfrey should not be used without the supervision of a qualified healthcare provider. Children, pregnant or nursing women, and the elderly are advised to never use comfrey under any circumstances. In addition, people suffering from alcoholism, liver disease, or cancer should also steer clear of comfrey. Finally, comfrey should never be applied to open wounds. If you do decide to use any comfrey lotions/ointments, choose only those products from a reputable and reliable distributor. You also want to choose products made from the leaves of the comfrey plant, because the roots are more toxic than the leaves.

Personally, I would rather find a different herb to use on my skin or as a medicinal herb. Comfrey will just remain as a rather attractive ornamental in my garden.

Remember to never use any herbal remedies without first consulting your primary healthcare professional or a certified herbalist.

References:

Houdret, Jessica. Practical Herb Garden. London, England: Hermes House, 2003.

Kowalchik, Claire and William H. Hylton, eds. Rodale's Illustrated Encyclopedia of Herbs. Emmaus, PA: Rodale Press, Inc., 1998.

University of Maryland Medical Center. Comfrey.