Coltsfoot's therapeutic uses

DEFINITION: Natural plant product used to treat specific health conditions.

PRINCIPAL PROPOSED USES: Not recommended for any purpose, although traditionally used for respiratory conditions and inflammation

Overview

The herb coltsfoot has a long history of use in herbal medicine in Europe and Asia as a treatment for coughs and sore throats. It does not appear that traditional herbalists recognized that this treatment, which they often recommended for children, may cause liver damage.

Therapeutic Dosages

Horticulturists have developed a form of coltsfoot that does not carry toxic pyrrolizidine alkaloids. When available, products of this type should be safer. Nonetheless, because experts do not know if coltsfoot offers any benefit, it is impossible to state an effective dosage.

Therapeutic Uses

Germany’s Commission E, the scientific body assigned to approve herbal treatments in Germany, once approved coltsfoot to treat sore throat. However, coltsfoot was subsequently banned due to its content of potentially liver-toxic substances called pyrrolizidine alkaloids.

Safety aside, no meaningful evidence exists that coltsfoot has any medicinal effects. The evidence available is from test tubes and animal studies. Only double-blind, placebo-controlled trials can prove a treatment effective, and none have been reported for coltsfoot. Much the same situation prevails for conventional cough syrups, none of which have been proven effective. However, they appear to be safe. Coltsfoot continued to be studied in the twenty-first century for potential health benefits, with researchers investigating its anti-inflammatory role in protecting brain health, preventing gout, helping wounds heal, and fighting respiratory infections.

Safety Issues

The pyrrolizidine alkaloids found in coltsfoot are known to have potential liver-toxic and cancer-promoting effects. One case report indicates that the use of coltsfoot tea in an infant caused severe liver problems that gradually disappeared when the tea was stopped. In another case, an infant developed liver disease and died because the mother drank tea containing coltsfoot during her pregnancy. Similar pyrrolizidine alkaloids are found in the herb comfrey, which has been associated with additional cases of liver injury.

Supporters of herbal therapy have defended the use of coltsfoot on the grounds that it was used for many thousands of years without harm. A flaw exists in this reasoning. Traditional herbalists would be expected to notice immediate, dramatic reactions to herbal formulas, and one can assume with some confidence that treatments used for thousands of years are unlikely to cause such immediate problems in very many people who take them. However, certain types of harm could be expected to elude the detection of traditional herbalists. These include delayed safety problems that occur relatively rarely or are difficult to detect without scientific instruments. How would a traditional herbalist ever know, for example, if a treatment caused liver failure in 1 of 100,000 people who used it, especially if such failure took two or more years to develop? If such a death did occur in the herbalist’s patient population, it would probably be attributed to hepatitis or some other common cause. These factors may explain why traditional Chinese herbal medicine uses treatments that are now recognized as dangerous, such as mercury, arsenic, lead, and the kidney-toxic herbs in the Aristolochia family.

Coltsfoot appears to fall into the same category. Most people can probably take coltsfoot briefly and suffer no injury. However, a few people (especially infants) may have greater sensitivity and suffer harm. Many more people may experience harm if they use coltsfoot for a prolonged period. For all these reasons, experts strongly recommend against using coltsfoot.

Bibliography

Ajmera, Rachael. "Coltsfoot: Potential Benefits, Side Effects, and Dosage." Healthline, 29 May 2019, www.healthline.com/nutrition/coltsfoot#benefits. Accessed 13 Sept. 2024.

Blumenthal M, et al., editors. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Austin, Tex.: American Botanical Council, 1998.

Lefton, Jennifer. "Coltsfoot: Uses, Side Effects, Risks, and More." Verywell Health, 9 Aug. 2024, www.verywellhealth.com/coltsfoot-benefits-side-effects-dosage-and-interactions-4685633. Accessed 13 Sept. 2024.

Schroeder, K., and T. Fahey. "Over-the-Counter Medications for Acute Cough in Children and Adults in Ambulatory Settings." Cochrane Database of Systematic Reviews, 23 Jan. 2008.

Stickel, F., and H. K. Seitz. "The Efficacy and Safety of Comfrey." Public Health Nutrition, vol. 3, 2000, pp. 501-508.

Wawrosch, C., B. Kopp, and H. Wiederfield. "Permanent Monitoring of Pyrrolizidine Alkaloid Content in Micropropagated Tussilago farfara: A Tool to Fulfill Statutory Demands for the Quality of Coltsfoot in Austria and Germany." Acta Horticulturae, vol. 530, 2000, pp. 469-472.