Safety Of Comfrey In Creams

In 2001, the U.S. Food and Drug Administration advised the manufacturers of dietary supplements containing comfrey to remove those products from the market. Comfrey contains substances that are toxic to humans when absorbed through the digestive tract. Although these same toxins can be absorbed through the skin, the rate of absorption is slower and comfrey is still used in a variety of topical applications, including creams, for medicinal purposes.

Chemistry

According to the Institute for Traditional Medicine, comfrey contains pyrrolizidine alkaloids, or PAs, molecules found in chlorophyll that are toxic to humans. When absorbed into the system, PAs become hepatoxic, or dangerous to the liver, as they metabolize. PAs can damage genes, cause problems with cell division and lead to the development of cancer. Its effects are cumulative in the body, meaning that the more comfrey is used, the greater the risk of harm.

Parts Used

Comfrey is a high-yielding perennial shrub that grows up to five feet in height. The leaves are the most commonly used part of the plant, but the roots are used to create extracts as well. Eight types of pyrrolizidine alkaloids are found in comfrey plants, with the highest concentrations found in the roots, according to the Cornell University Department of Animal Science.

Function

Comfrey is used in creams, lotions and ointments for the topical treatment of bruises, burns, inflammation and strains or sprains. Creams sometimes combine comfrey with other herbal remedies, including aloe, calendula or goldenseal. The University of Maryland Medical Center states that comfrey plants contain allantoin, rosmarinic acid and tannins, compounds that stimulate new skin cell growth and reduce inflammation.

Research

Research published in the September 2004 issue of "Phytomedicine" studied 142 people with acute ankle sprains who either used an ointment of comfrey root extract or a placebo to reduce pain and swelling associated with the sprain. The study found that the ointment containing comfrey root extract provided superior treatment of the pain and swelling, and increased ankle mobility when compared to the placebo ointment.

Because the effects of the pyrrolizidine alkaloids in comfrey are cumulative in the body, the University of Maryland Medical Center warns against using topical products containing high concentrations of comfrey root. It also advises avoiding the use of any product containing comfrey on scrapes or open wounds. Topical products containing comfrey root should be used for 10 consecutive days or less, and for a maximum of four to six weeks annually to reduce the amount of PAs in the body.

Children and the Elderly

Because their immune systems are more susceptible to toxins, the University of Maryland Medical Center recommends that children and the elderly do not use any product containing comfrey, including creams.