Introduction
Comfrey is an herb or plant belonging to the Boraginaceae family that has characteristic small purple flowers and is found in Europe, Asia, and North America mostly. Comfrey teas are considered rejuvenating herbal drinks while comfrey topical creams are considered to be skin-healthy. However, these benefits are not true. Comfrey tea is prepared from the leaves of the Symphytum officinale or the common comfrey plant. This perennial plant is primarily a native of the European continent, but it is also grown widely in many parts of the globe like western Asia, North America, and Australia as well. This comfrey plant is described to have a rather blackish-coloured, turnip-like root with the broad plant leaves being hairy and prickly. The comfrey plant bears only small purplish or cream-coloured flowers. Comfrey also goes by the names of salsify, slippery root, black root, black wort, bruise wort, and many more.
What Are the Uses of Comfrey in Traditional Medicine?
Traditionally, comfrey was referred to as knitbone or boneset. The tea prepared from it was reportedly recognized for its medicinal benefits and was used by the ancient Greeks and Romans, primarily for healing skin injuries resulting from severe impacts, skin trauma, falls, or accidents. Consumption of comfrey tea was originally believed to aid in the following benefits:
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Relieving the excess menstrual flow.
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Scar reduction or improved primary and secondary wound healing.
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Relief from burns or cuts.
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Treatment of pulmonary bronchitis (inflammation of bronchioles).
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For treatment of rheumatoid arthritis and joint pains.
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In treating skin rashes, allergies, or insect bites.
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In treating fractured bones, bone or muscle sprains, and muscle strains.
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In aiding to relieve body aches or cramps.
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For improvement in the tooth enamel or dental health.
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Aiding in improved blood circulation.
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Acts as a smoothening agent for the skin and relieves acne.
According to current nutrition research and studies, all of the above-enlisted benefits are not verified by scientific evidence or by research. Hence there is no scientific evidence regarding these benefits of comfrey on the human immune system or body.
Why Comfrey Products Are Not Currently Recommended?
As per the information given by the Memorial Sloan Kettering Cancer Center (MSKCC), both the comfrey root and the comfrey leaves comprise chemical substances that are more likely to impact systemic health in a negative manner. This is attributed to the presence of compounds allantoin, rosmarinic acid, and pyrrolizidine alkaloids according to published research studies. According to the information provided by the Therapeutic Research Center (TRC)- the natural medicine database reports show that comfrey can be only applied topically (because of its long history of medicinal benefit as an analgesic) for relieving backaches, osteoarthritis (a degenerative joint disease that involves the breakdown of cartilages in the joints, leading to pain and stiffness), joint pains, or muscle sprains.
As per the MSKCC along with many other known health agencies focusing on the comfrey benefits, the lack of scientific evidence and the chemicals present in the root and leaves of comfrey demonstrate that it is best to avoid comfrey tea especially due to safety concerns and serious impact on individual health. Hence, while in alternative medicine or in some herbal treatments, comfrey tea is quite a popular choice that serves as an analgesic for relieving body aches, and pains as well as promoting wound healing. It is not advised as such by many health experts currently (according to recent nutrition-based evidence) across the globe because of chemicals present in the comfrey called pyrrolizidine alkaloids (PAs) - that may be harmful to systemic health. As of now, only the comfrey products are popular for being used for external applications or only for external skin condition-related use. Also, while comfrey tea can be easily prepared in the comfort of one’s home, there are several reasons why this tea may be more harmful than beneficial, which is why many health experts or nutrition experts do not recommend it.
Can the Plant Alkaloids Be Hepatotoxic?
According to information and instructions provided by the United States Food and Drug Administration (FDA) in 2001, most supplement manufacturers were advised to remove products containing comfrey from commercial markets. This recommendation followed investigations into reports found in the "poisonous plant database," which revealed the presence of chemical compounds in comfrey. These compounds were identified as potentially hepatotoxic (liver toxic) or capable of inducing cell growth or spread, potentially triggering certain cancers. The association of these health risks was primarily attributed to the naturally occurring "pyrrolizidine alkaloids" in the plants. Pyrrolizidine alkaloids are common secondary plant compounds with known properties of hepatotoxicity and carcinogenicity. Current research also links the biological activities or impact of these compounds to the development of hepatic veno-occlusive disease and liver cancers.
What Are the Safety Concerns for the Long-Term Use of Comfrey Creams?
Commercially, the comfrey creams found in markets typically consist of a common combination of ingredients such as oils or water, along with glyceryl stearate and Symphytum officinale, or comfrey plant extract. Although the natural medicine database suggests that comfrey topical creams or products are possibly safe for skin-based or topical application, there is a lack of scientific reports or evidence demonstrating their benefits when used for more than a week. Additionally, concerns arise for topical applications exceeding 10 days. This is why pregnant or breastfeeding women should completely avoid applying comfrey creams, either topically on the skin or for oral use.
Conclusion
Comfrey tea, once popularized in previous decades, was traditionally associated with the comfrey plant and its use in alternative medicine for treating body aches and pains. However, in the last decade, nutrition experts have expressed concerns about the efficacy of comfrey products, including comfrey tea. It is crucial to highlight that there is currently no scientific evidence supporting the medicinal impact of comfrey plant products. Consequently, whether consumed as a tea or used topically in creams, safety concerns arise due to the presence of chemical alkaloids that may have hepatotoxic or cancer-causing effects. As a result, choosing comfrey as a food or for topical application is discouraged.
