Background

• Once considered a sacred herb in Celtic tradition, mistletoe has been used for centuries for conditions as diverse as high blood pressure, epilepsy, exhaustion, anxiety, arthritis, vertigo (dizziness), and degenerative inflammation of the joints.
• Beginning in the early 20th Century, mistletoe came into practice in Europe as an anti-cancer therapy and this remains a source of great popular interest. For example, in Norway, mistletoe has been considered a "non-proven therapy" or NPT but has been used as a popular method for healing.
• In the last 50 years, many laboratory, animal, and human studies have been conducted on potential anti-cancer effects thought to be caused by immuno-stimulatory effects of mistletoe.
• The most promising potential use is as a cancer therapy, but there is still insufficient clinical evidence to consider it a proven cancer therapy. Toxic effects seem to be rare, but have been reported. The National Cancer Institute monograph "Mistletoe Extracts" provides a complementary and alternative medicine (CAM) information summary and overview of the use of mistletoe as a treatment for cancer, indicating that: [a] in animal studies mixed results have been obtained using mistletoe extracts for slowing tumor growth; [b] well designed clinical trials using mistletoe or its components have not been sufficient to prove efficacy in the treatment of human cancer(s); [c] mistletoe plants and berries are toxic to humans and their extracts are not sold in the United States.
• Mistletoe is not commercially available in the United States, but two U.S. investigators currently have Investigational New Drug approval (IND) from the U.S. Food and Drug Administration (FDA) to study mistletoe.
• The German Commission E Monographs list mistletoe as a treatment for degenerative inflammation of the joints and as palliative therapy for malignant tumors.
• Two major types of mistletoe, European and American, contain very similar proteins and are reputed to have different uses. European mistletoe is believed to reduce blood pressure and act as an antispasmodic and calmative agent, while American mistletoe is believed to simulate smooth muscles, increase blood pressure, and trigger uterine and intestinal contractions. However, there is little research to substantiate any of these claims.

References

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