How It Works
Bottom Line: Slippery elm should not be used to treat cancer, ulcers, diarrhea, bronchitis, or other medical conditions, because there is absolutely no evidence that it works.
Although no laboratory research has been done with slippery elm per se, scientists are familiar with the effects of the fiber content in this bark extract. Slippery elm products contain mucilage, a sticky mixture of complex sugars that cannot be broken down by the human digestive tract. For this reason, it acts as a laxative. Mucilage also generally has a soothing effect when applied topically, and relieves cough when taken by mouth, but these effects have not been shown specifically for slippery elm.
Purported Uses
To treat coughs and bronchitis
The mucilage content in slippery elm is thought to relieve coughs, but there is no proof from clinical trials that this effect occurs in humans.
To treat cancer
No scientific evidence supports this use.
To treat diarrhea
No scientific evidence supports this use. In fact, slippery elm may have laxative effects.
To reduce fever
No scientific evidence supports this use.
To reduce inflammation
No scientific evidence supports this use.
To treat peptic ulcers
No scientific evidence supports this use.
Topically, to treat skin abscesses and ulcers
The mucilage content in slippery elm is thought to have a soothing effect when applied topically, but there is no proof from clinical trials that it can be used to treat skin abscesses or ulcers.
To treat a sore throat
No scientific evidence supports this use.
Research Evidence
No research, either in humans or in animals, has been performed on slippery elm to test whether it is safe or effective for any of its proposed uses.
Warnings
This product is regulated by the FDA as a dietary supplement. Unlike approved drugs, supplements are not required to be manufactured under specific standardized conditions. This product may not contain the labeled amount or may be contaminated. In addition, it may not have been tested for safety or effectiveness.
Do Not Take If
You are taking any other medications by mouth at the same time (In theory, the high fiber content of slippery elm can reduce the absorption of other drugs taken at the same time, thereby reducing their effectiveness).
Special Point
Slippery elm appears to be safe for coughs and minor gastrointestinal complaints, but it should not be used to treat severe conditions such as cancer or bronchitis.
Scientific Name
Common Name
Indian Elm, red elm, gray elm
Clinical Summary
Derived from the inner bark of the tree. Slippery elm has been used historically for gastrointestinal disorders, skin ulcers or abscesses, cancers, cough, fevers, and inflammation. The primary constituent is mucilage, which is thought to account for the demulcent effects. To date, no human or animal studies have been performed to evaluate the efficacy of any proposed claims. Toxicity of slippery elm is low based upon chemical components. No adverse reactions or drug interactions are reported in the literature. Slippery elm appears to be safe for coughs and minor gastrointestinal complaints, but it should not be used to treat severe conditions such as cancer or bronchitis.
Purported uses
Bronchitis
Cancer treatment
Cough
Diarrhea
Fever
Inflammation
Peptic ulcers
Skin abscesses
Skin ulcers
Sore throat
Constituents
Carbohydrates: Mucilage (hexose, pentose, methylpentose), galactose, glucose, galacturonic acid
Phytosterols: Beta-sitosterol, citrostandienol, dolichol
Fatty acids: Oleic and palmitic acid
Other: Tannin, calcium oxalate, cholesterol
(1) (2)
Mechanism of Action
Mucilage is responsible for the demulcent, emollient, and antitussive properties. Insoluble polysaccharides in mucilage (hexose, pentose, methylpentose) form a viscous material following oral administration or when prepared for topical use. Fiber content is thought to reduce gastrointestinal transit time, act as a bulk forming laxative, and adsorb toxins. Fatty acid esters such as oleic and palmitic acid are thought to be responsible for antitumor activity.
(2) The tannin component has been shown to exhibit astringent activity
(1).
Adverse Reactions
No adverse reactions have been reported.
Herb-Drug Interactions
Theoretically, slippery elm may slow the absorption of concomitantly administered oral medications
(3).
Literature Summary and Critique
No human or animal studies have been performed to evaluate the efficacy of any proposed claims.
References
