Essiac has not been shown to treat or prevent cancer.
Essiac was developed in the 1920s by Rene Caisse, a Canadian nurse, and promoted as an alternative cancer treatment. It contains four botanicals: burdock root, sheep sorrel, slippery elm, and rhubarb. Laboratory studies have shown that Essiac has antioxidant and cytotoxic properties. But results are conflicting on Essiac’s antiproliferative effects. Essiac prevented growth of prostate cancer cells but stimulated growth of breast cancer cells. In a study of breast cancer patients, Essiac did not improve quality of life or mood. Despite unsubstantiated claims, Essiac remains a popular anticancer therapy today.
Purported Uses
To treat cancer
Laboratory studies showed conflicting results. An observational study of breast cancer patients did not find any improvement in quality of life with Essiac.
To treat HIV and AIDS
There is no clinical evidence to support this use.
To stimulate the immune system
In laboratory studies, rhubarb, an ingredient of Essiac, suppressed activity of part of the immune system. Human studies are lacking.
As a tonic
There are no clinical data to back this claim.
Do Not Take If
You have kidney or liverproblems.
You are undergoing chemotherapy (in a case report, levels of a chemotherapy drug were increased in the blood of a patient also taking Essiac, with the potential for increased toxicity.)
Side Effects
Case Report: A 59-year-old woman reported symptoms of anorexia, nausea, myalgia, fatigue, and generalized abdominal pain following consumption of Essiac tea for six months. Her symptoms resolved after discontinuing the tea.
The manufacturer of Flor Essence states that users may experience increased bowel movements, frequent urination, swollen glands, skin blemishes, flu-like symptoms, or slight headaches.
Essiac was developed in the 1920s by Rene Caisse, a Canadian nurse, and promoted as an alternative cancer treatment. It is a formulation of four botanicals: burdock root, sheep sorrel root, slippery elm bark, and rhubarb root (1)(2).
Essiac demonstrated antioxidant (12) and cytotoxic properties in vitro (6)(11), but stimulated growth of human breast cancer cells both via estrogen receptor (ER)-dependent and ER-independent pathways (3). Similarly, studies of its antiproliferative effects on prostate cancer cells yielded conflicting data (7)(8). Remission of hormone-refractory prostate cancer was reported in a patient (9), but a retrospective study of breast cancer patients found that Essiac did not improve quality of life or mood (10). Despite unsubstantiated claims (5), Essiac remains a popular anticancer therapy today.
Purported Uses
Cancer treatment
Health maintenance
HIV and AIDS
Immunostimulation
Mechanism of Action
Rhubarb and sheep sorrel contain anthraquinones that stimulate secretion of mucosa and water, as well as stimulate peristalsis. Additional activities of anthraquinones isolated from rhubarb show stimulation of IL-1, IL-6, and TNF in vitro and tumor necrosis against sarcoma 37, breast cancer, and Ehrlich cell lines in mice. Burdock root can induce hypoglycemia in animal models. Tannin extract may induce macrophage response and the lignan and sesquiterpene extracts were shown to inhibit platelet activating factor (PAF) in vitro (1)(2). Essiac was also shown to inhibit cytochrome P450 (CYP450) enzymes in vitro (6).
Contraindications
Theoretically, patients with renal or hepatic insufficiency should not consume this product.
Adverse Reactions
Case Report: A 59-year-old woman reported symptoms of anorexia, nausea, myalgia, fatigue, and generalized abdominal pain following consumption of Essiac tea for six months. Her symptoms resolved after discontinuing the tea (13).
The manufacturer of Flor Essence states that users may experience increased bowel movements, frequent urination, swollen glands, skin blemishes, flu-like symptoms, or slight headaches (14).
Herb-Drug Interactions
Cytochrome P450: Decreased clearance of an experimental chemotherapy drug was reported in a patient taking Essiac (4). This may be due to inhibition of cytochrome P450 enzymes by Essiac (6).
Geyer C, et al. Dose-schedule optimization the hexacyclic camptothecin (CPT) analog dx-8951f: a phase I and pharmacokinetic study with escalation of both treatment duration and dose (meeting abstract). Proc Annu Meet Am Soc Clin Oncol. 1999;18.
