

Essiac, Vitaltea®, Flor-Essence®
Essiac was developed in the 1920s by Rene Caisse, a Canadian nurse. 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 Essiac’s 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 unsubtantiated claims (5), Essiac remains a popular anticancer therapy today.
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).
Bottom Line: Essiac has not been shown to treat or prevent cancer.
Essiac was developed in the 1920s by Rene Caisse, a Canadian nurse. 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. Patients should avoid use of Essiac as it may delay conventional care.