Native Americans cherished and used the bark of slippery elm for thousands of years in traditional medicine. It was taken to relieve sore throats, stomach and bowel inflammation, to heal wounds, urinary tract infections, and even cancer. Read on to find out if you should be using slippery elm, especially if you have IBS or IBD, and what health benefits are supported by science.
What is Slippery Elm?
Ulmus rubra, commonly known as Slippery Elm or Moose Elm, is a deciduous red tree native to North America and Canada. The tree can grow up to 25 m and its inner bark has a reddish-yellow or reddish-brown color .
Slippery elm got its name because its inner bark feels slippery when chewed or mixed with water. The inner bark contains mucilage, a slime-like substance that turns into a gel when it comes in contact with water. Mucilage is a mix of polysaccharides with many medicinal properties [2, 1].
Slippery elm was used by the Native Americans for many purposes, including building canoes and making fire, but also for promoting health. Traditionally, the inner bark of slippery elm has been used as a natural remedy for [1, 3, 4, 5]:
- Urinary tract infections
- Skin injuries and diseases
- Sore throat & throat infections
- Stomach and bowel inflammation
The potential benefits of slippery elm are difficult to fully assess, given the lack of clinical studies. However, limited evidence suggests that slippery elm can help with irritable bowel syndrome (IBS), skin conditions, and inflammation [6, 7, 8].
The mucilage of slippery elm contains polysaccharides (l-rhamnose, d-galactose, 3-O-methyl-d-galactose, d-galacturonic acid, pectin). After the mucilage comes in contact with water, these polysaccharides break down to sugars (galactose, glucose, and fructose) [9, 10, 11, 12].
- Simple sugars (hexoses, pentoses)
- Fatty acids (oleic and palmitic acid)
- Phytochemicals and sterols (oleanolic acid, ursolic acid, beta-carotene, beta-Sitosterol, citrostadienol)
Mechanism of Action
Slippery elm contains mucilage. Mucilage is a substance made from polysaccharides. When mucilage comes in contact with water, it swells up and becomes a gel. This gel can soothe dry or inflamed skin, such as in psoriasis. Mucilage can also heal injuries and wounds, soothe a dry throat and reduce throat inflammation [8, 14, 15, 16].
Slippery elm may help with digestive health problems, as:
- Mucilage can soothe an inflamed gut, act as a laxative, and relieve constipation [8, 6, 8]
- Other components can block harmful gut bacteria (such as Citrobacter freundii and Klebsiella pneumoniae) and increase good gut bacteria (such as Bifidobacterium, Lactobacillus, and Bacteroides species) [17, 18, R].
Slippery elm may fight inflammation and cancer by:
- Blocking the release of oxygen radicals (superoxide, peroxyl) involved in inflammation, blood vessel damage, DNA damage, and cancer [19, 20, 21, 22].
- Decreasing the production of interleukin 8 (IL-8), a cytokine that can cause inflammation and cancer [23, 24].
Slippery Elm Health Benefits & Uses
1) Slippery Elm May Improve IBS
Irritable bowel syndrome (IBS) is a chronic disorder that impacts the stomach and intestines. Symptoms include diarrhea or constipation (usually one will be dominant), straining, stomach pains, and bloating [25, 26, 27].
Slippery elm is a better option for people with constipation IBS, as it can increase bowel movements. In people with diarrhea IBS, it may reduce some symptoms but may worsen the diarrhea.
- Increased stool frequency by 20%
- Improved stool consistency by 29%
- Reduced straining by 65 %
- Relieved stomach pain and bloating by ~13%
- Reduced straining and stomach pain by ~20%
- Decreased bloating by 28%
- Reduced gas and flatulence by 18%.
However, it didn’t help with diarrhea. On the contrary, it increased the frequency of bowel movements by 9%.
3) Slippery Elm May Relieve Sore Throat (Pharyngitis)
Throat Coat is a herbal medicine made from slippery elm, licorice root, and marshmallow root .
4) Slippery Elm May Improve Psoriasis
Psoriasis is a chronic, inflammatory skin condition that causes red patches and scales over the skin .
In 5 people with psoriasis, slippery elm together with saffron tea and a special diet improved all psoriasis symptoms, such as redness, skin thickness, scaling, and the area of the affected skin .
5) Slippery Elm May Improve Acid Reflux/GERD
Gastroesophageal reflux disease (GERD) is a digestive disorder that causes stomach contents to return back up into the esophagus. Symptoms include heartburn and a sensation of bitter-tasting acid in the throat or mouth (acid regurgitation) [32, 33, 34].
6) Slippery Elm May Reduce Migraines
Slippery elm together with multivitamins and a magnesium supplement reduced chronic migraines in a 23-year old female with GERD. Slippery elm may have helped more with acid reflux than with migraine, for which magnesium is known to be beneficial .
Further research on the benefits of slippery elm for migraines is needed to tease apart the effect.
7) Slippery Elm Is an Antioxidant
8) Slippery Elm May Reduce Weight and Blood Fats
9) Slippery Elm Balances the Gut Microbiome
Slippery elm can also reduce the harmful bacteria in the gut that can cause inflammation. These include bacteria that cause :
- Urinary tract infections (Citrobacter, Pseudocitrobacter, Enterococcus )
- Urinary tract, respiratory, skin, and stomach infections (Enterobacter)
10) Slippery Elm May Fight Cancer
In rats with leukemia, slippery elm together with 3 other herbs (burdock root, sheep sorrel, and Chinese rhubarb) restored the number of total white blood cells, lymphatic white blood cells (lymphocytes), and bone marrow white cells (neutrophils) .
In mice cells, this herb mix also decreased the production of immature blood cells and blocked the production of S1P1 (Sphingosine-1-phosphate receptor 1) (S1P1), a protein involved in leukemia [40, 41].
Essiac is a herbal mixture of slippery elm and burdock root, Indian rhubarb, and sheep sorrel. In cell studies, Essiac blocked the release of free radicals and reduced DNA damage. Essiac also blocked the growth of breast cancer cells [42, 43].
11) Slippery Elm May Help with IBD
How can slippery elm help?
Slippery Elm may alter the gut microbiota in IBD
Altered gut microbiota can cause IBD .
People with IBD have lower levels of health-promoting Bacteroides bacteria in the gut. Moreover, Lactobacillus spp. and Bifidobacterium spp. are given as probiotics to people with ulcerative colitis or Crohn’s disease [48, 49].
Slippery elm can fight harmful bacteria that worsen bowel and stomach inflammation, such as Enterobacter, while increasing health-promoting bacteria, such as Bifidobacterium spp., Lactobacillus spp., and Bacteroides spp .
Slippery Elm may fight inflammation in IBD
In a cell study, slippery elm blocked the release of oxygen radicals involved in ulcerative colitis .
Slippery Elm For Pets
Slippery elm is a safe herbal supplement that can be given to cats and dogs for digestive problems such as constipation and bowel inflammation.
Slippery elm killed parasites in the stomach and reduced stomach problems, food poisoning, stopped diarrhea and promoted colon health in dogs, cats, and pigs .
Slippery elm together with psyllium husks reduced the symptoms of hairballs (vomiting, retching, or coughing) in cats .
Pregnant or breastfeeding women should be cautious with slippery elm. Traditionally, it was believed to cause abortions or miscarriages. However, taking slippery elm as a powder or tea is probably not harmful. The risk comes only from using the bark vaginally [55, 56].
Despite the lack of scientific evidence, pregnant women believed that they could trigger an abortion by inserting slippery elm into their cervix. Some cases of slippery elm in the bladders’ of pregnant women have been recorded, although none of them had a miscarriage [55, 56].
Slippery elm contains mucilage, which can reduce the absorption of oral drugs and decrease their effectiveness. Therefore, you should take slippery elm at least one hour after taking an oral drug and consult your doctor or pharmacist about possible interactions with your prescription medication .
In rats, slippery elm together with other herbs (burdock root, sheep’s sorrel, and Chinese rhubarb) blocked the release of S1P1 (Sphingosine-1-phosphate receptor 1), a protein encoded in the S1P1 gene involved in leukemia [40, 41].
Forms of Supplementation and Dosage
Slippery elm, as a herbal supplement, is available in the form of tea, lozenges, capsules, and powder .
Many supplements are available and because none are standardized, the dosage recommendations greatly vary.
As a rule of thumb, please consider the following :
- For gruel: 1.5 – 3 gr of powder in 1 cup (240ml) of water
- For tea: 4 grams of powder in 2 cups of water
- For capsules: 200mg – 500mg up to three times a day
- For lozenges: 1 lozenge daily
Most users were happy with slippery elm. They reported it reduced the symptoms and promoted healing in cases of:
- Irritable bowel syndrome (IBS)
- Inflammatory bowel disease (IBD)
- Acid reflux/GERD
- Stomach ulcer
- Sore throat and dry mouth
- Vaginal yeast infections
There are many supplements widely available but not standardized, so the time it takes for slippery elm to work varies greatly. However, users reported improvements after the first capsule or after the first powder dosage.
However, a few users experienced side effects and health disturbances, such as constipation, diarrhea, and skin allergies.
Limitations and Caveats
Studies about the benefits of the slippery elm are limited and many are reviews rather than clinical trials.
Furthermore, the few clinical trials that were carried out had a small number of participants, and some of their findings are debatable. In most of the clinical studies, slippery elm was only one component of the diet/therapy examined.
Further research on the benefits and side effects of slippery elm is needed.