The good, the bad and the comfrey
H.E. Kirschner’s thin book Nature’s Healing Grasses contains 71 pages of his observations about a dozen “wayside weeds” and other common plants whose nutritional benefits were under new-found scrutiny in the 1950s and ‘60s. He devoted 21 pages to comfrey– “the miracle herb.”
Kirschner stated the allantoin in comfrey leaves and roots was touted as a “cell-proliferant – in making the edges of wounds grow together, healing sores, and taken internally for gastric and duodenal ulcers.” He suggested comfrey moisturizing cream to clear up skin concerns. Plus, to get its blood-purifying effect, Kirschner would add fresh comfrey leaves to his green drink.
I remember reading reviews of comfrey in Organic Gardening which noted the leaves were effective in a compost at facilitating the composting process and useful as a mulch. Back then, every health food store sold comfrey leaves in bulk.
Comfrey and its cousins grow wild throughout Europe and western Asia, and the Latin name Synphytum is derived from the Latin for “grow together.” History records the medicinal use of comfrey from Rome to Sapporo for at least two millennia. Pliny the Elder wrote that he boiled a comfrey root and made a paste that glued pieces of meat together, which sounds like a terrific third-grade science fair project. Go, Pliny!
In the Dark Ages, monks of various orders grew comfrey in monastery gardens to use for healing the wounds of soldiers.
Nicholas Culpeper wrote in 1656 in The English Physician, “ … a Syrup made thereof is very effectual for all those… outward Wounds and Sores in the Fleshy or Sinewy part of the Body whatsoever.” Its nickname was knitbone.
Comfrey leaves were added to soups and fed to livestock. It also contains rosmarinic acid which relieves pain and inflammation. It seemed comfrey could do it all– the Roberto Clemente of herbal remedies.
I added comfrey leaves to my herb tea mixtures regularly until that dark cloud of a day in the 1970s when the scary news began to circulate. The world learned comfrey– “the miracle herb”– had a dark side. Studies and articles began to appear claiming the herb with a litany of healing properties also contained pyrrolizidine alkaloids which are toxic, readily absorbed internally or externally, and which increase the risk of liver damage.
Defenders explained away the reports at first by referring to the long, apparently safe, history of comfrey, but further research connected comfrey to liver cancer. Steven Foster states in Herbal Renaissance, “ …before a human consumes enough comfrey to develop liver cancer, he or she would probably have developed another disease – veno-occlusive disease of the liver – caused by comfrey’s pyrrolizidine alkaloids.”
In 2001, the Food and Drug Administration and the Federal Trade Commission banned the sale of oral comfrey products. Most countries have banned or restricted the sale of oral comfrey products, yet creams, salves and ointments containing comfrey are still marketed for sprains and bruises.
So, opinion is divided about the use of comfrey. Caution and moderation would seem prudent. If a gardener wants to grow comfrey, it might be the easiest plant to maintain you ever planted. It is usually propagated by placing a root cutting in carefully prepared soil, but you probably could achieve the same result by throwing the cutting left-handed over your shoulder and never looking back because comfrey intends to grow… and spread.
This weekend I noticed new comfrey leaves emerging along the garden fence at least 12 feet from the original location. Let’s read together from page 75 of Herbal Renaissance, first column, “Once planted in a spot, comfrey will be there forever.”
You might think you got rid of it by digging it up. You did not. And science says you shouldn’t eat it.