Most people are familiar with mistletoe as the plant we kiss under during the Christmas holidays, but did you know that mistletoe also has important medicinal properties? Its historical use can be traced back more than 2,000 years.  The ancient Greeks and Romans used mistletoe to treat a wide variety of health issues.
Mistletoe is the plant name given to many hemiparasitic plants. The various mistletoe species differ in their therapeutic actions, toxicities, and geographic locations.
There are nearly 100 species of mistletoe, which all fall in the genus Viscum and several types of Viscum have undergone rigorous scientific testing, which is especially true as it relates to cancer.
Viscum use for cancer is mentioned in the literate starting in the early 1900s. Dr. Ita Wegman around 1920 first developed its use as an injectable agent for cancer. Research has subsequently shown that Viscum has several notable effects.
First and foremost, Viscum is like an immune system enhancing therapy. It exerts its immune effects through various mechanisms, including:
- Increase in the number of immune system cells 
- and activity of immune system cells 
- Increase in the activity of various cytokines, including IL-1, IL-2, IL-6, interferon-g, and tumor necrosis factor-a
- Increase in body temperature
Viscum also has a cytotoxic (cancer cell-killing) effect through its inhibition of protein synthesis.  By blocking the production of specific proteins, cancer cell death via apoptosis ensues.
Also, Viscum has an anti-cancer effect — it inhibits angiogenesis, which is the production of new blood vessels. In the setting of cancer, new blood vessels are used to assist cancer in its growth and spread.
Perhaps as a result of its noted anti-cancer effects, mistletoe has been shown to improve quality of life.  Reductions in pain, diarrhea, nausea, vomiting, and insomnia have been seen in mistletoe studies.
Finally, mistletoe has been shown to be compatible with many chemotherapeutic agents, resulting in no negative herb-drug interactions.  This compatibility was shown to exist even when chemotherapy and Viscum were given simultaneously.
Due to its extensive clinical use worldwide for many years, coupled with solid scientific research supporting its use, we believe that mistletoe is a vital component in most integrative cancer treatment protocols.
- Bussing, Arndt. Mistletoe: The Genus Viscum. Amsterdam, The Netherlands: Harwood Academic Publishers, 2000. Print.
- Huber R, Barth H, Schmitt-Graff A, Klein R. Hypereosinophilia induced by high-dose intratumoral and peritumoral mistletoe application to a patient with pancreatic carcinoma.J Altern Complement Med. 2000; 6(4): 305-10.
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- Valentiner U, Pfuller U, Baum C, Schumacher U. The cytotoxic effect of mistletoe lectins I, II and III on sensitive and multidrug resistant human colon cancer cell linesin vitro. Toxicology 2002; 171(2-3): 187-99.
- Troger W, Zdrale Z, Tisma N, Matijasevic M. Additional therapy with a mistletoe product during adjuvant chemotherapy of breast cancer patients improves quality of life: an open randomized clinical pilot trial. Evid Based Complement Alternat Med 2014; 2014: 430518.
- Weissenstein U, Kunz M, Urech K, Baumgartner S. Interaction of standard mistletoe (Viscum album) extracts with chemotherapeutic drugs regarding cytostatic and cytotoxic effects in vitro. BMC Complement Altern Med 2014; 4: 6.