A twisted slippery elm tree

For centuries, the soft inner bark of the slippery elm tree (Ulmus fulva) has been used by Native Americans for treatment in a variety of health conditions, including:

  • Skin wounds and burns
  • Sore throat
  • Cough
  • Gastroesophageal Reflux/Heartburn
  • Inflammatory Bowel Disease (ulcerative colitis and Crohn’s disease)
  • Irritable Bowel Syndrome
  • Diarrhea
  • Psoriasis and other skin conditions
  • Cancer

The inner bark of the slippery elm tree has also been used historically in a porridge for infants recovering from illness. Additionally, as a testament to its skin healing properties, many Civil War heroes credit slippery elm with healing their war injuries.

How Does it Work?

The purported health benefits of slippery elm bark are derived from the biochemical compounds that can be extracted from the herb. These compounds include mucilage, plant sterols, fatty acids, tannins, and calcium oxalate. The mucilage found in slippery elm bark gives the plant its ability to soothe sore throats and suppress coughs, while the fiber content quickens passage of food through the gastrointestinal tract, acts as a laxative, and binds toxins. The fatty acids, tannins, and sterols have been shown to have antioxidant and anti-inflammatory properties.

Notably, a clinical study showed that patients with active ulcerative colitis experienced a dose-dependent decrease in gastrointestinal mucosal free radical concentration when treated with slippery elm bark. In addition, plant sterols can help to lower cholesterol and prevent cardiovascular disease when consumed as part of a healthy diet.

Slippery Elm Bark Benefits for Cancer

The antioxidant and anti-inflammatory properties of fatty acids, tannins, and plant sterols may all contribute to slippery elm bark’s use as adjunctive cancer treatment in complementary and alternative medicine. In addition to its benefits as a single plant, though, slippery elm bark is one of the constituents in the herbal mixture Essiac tea, a popular form of cancer treatment in alternative and complementary medicine.

Essiac tea was created by a native Ojibwa healer long ago and brought to popular attention through the works of Canadian nurse Rene Caisse. Along with slippery elm bark, the Essiac recipe is made with sheep sorrel, burdock root, and Turkish rhubarb. Laboratory studies have shown that both the individual herbs in Essiac tea have general anticancer properties, such as anti-inflammatory, antioxidant, and immune strengthening effects. In addition to cancer-specific cell killing for some of the constituent herbs, essiac tea has also been shown to have an anti-estrogenic effect, which can help fight cancer in estrogen-responsive cancers, such as breast cancer.

Slippery Elm Side Effects are Minimal

Slippery elm bark is considered a relatively safe supplement, though it has not been well-studied. Occasional allergic reactions have been reported. Also, the mucilage coats the gastrointestinal tract and therefore can slow down the absorption of other drugs or supplements.

No contraindications are reported, both in terms of medical conditions and concurrent drugs. It remains unclear whether slippery elm bark is safe in pregnancy and breastfeeding; therefore, most health practitioners would recommend avoiding it and most other herbal supplements during either of these states. Maximum safe dose has also not been established for children or those with severe kidney or liver disease.

Slippery elm bark has a centuries-long tradition of being used for a number of health-related issues, most notably cancer, skin conditions, and respiratory tract infections. It is generally believed to be safe with no serious side effects or contraindications, but as with any herbal supplement, should still be used with caution and under the supervision of a health practitioner.