Mistletoe therapy has a long history of use as a complementary treatment for cancer. As a powerful immune stimulant, mistletoe helps kill cancer cells and helps prevent the growth of new blood vessels needed for tumours to grow.
Mistletoe extract (Viscum album L or European mistletoe) as a treatment for cancer came into use around 1920. Since then, further knowledge regarding its anticancer effects has emerged based on almost 100 years of clinical use, as well as a large and growing body of research.
Mistletoe’s two modes of action
Potent immune stimulant
Mistletoe contains components called lectins (a type of protein) that bind to receptors on immune cells (lymphocytes) and increase their anticancer surveillance. In other words, mistletoe enhances the “seek out and destroy” capacity of the immune system against cancer cells.
It also helps to offset the immune suppression that is often induced by radiation and chemotherapy.
Cytotoxic effects
Mistletoe also possesses direct cytotoxic effects. This means that it contains components, including viscotoxins, that are toxic to tumour cells, causing tumour cell death.
How mistletoe is used
Mistletoe therapy is used to augment the antitumour effects of chemotherapy, minimize side effects, and improve quality of life. It is also used to help reduce risk of recurrence in patients who have completed treatment. It is typically administered as an injection therapy under the supervision of a skilled naturopathic doctor who can monitor treatment reactions and progress appropriately.
Research into mistletoe therapy
There is a large body of evidence that attests to the benefits of mistletoe therapy.
A systematic review published in 2008 by the Cochrane Collaboration examined data from 21 randomized studies. Of the trials reviewed, six of 13 studies showed a benefit to survival, and 14 of 16 showed benefit to quality of life and/or symptom burden.
The strongest data showed that there was benefit to quality of life for breast cancer patients undergoing chemotherapy. Researchers concluded that “mistletoe extracts were usually well tolerated and had few side effects.”
Other studies have shown possible benefit for prevention of cancer recurrence—for instance, in patients with bladder cancer who have successfully undergone tumour removal.
In patients with advanced pancreatic cancer, an aggressive type of cancer, treatment with mistletoe has been shown to improve measures of quality of life, including pain, fatigue, appetite loss, and insomnia, compared to patients who received supportive care alone.
Another study of patients with early stage breast cancer undergoing chemotherapy found that those patients who received mistletoe therapy had better quality of life, and half the incidence of neutropenia (a serious form of immune suppression induced by chemotherapy), compared to patients who did not receive mistletoe.
Mistletoe therapy requires ongoing supervision. Be sure to consult with a licensed naturopathic doctor experienced in treating cancer in order to find out if mistletoe is an appropriate therapy for you.
Heidi Fritz, MA, ND, is a research fellow and practices at the Bolton Naturopathic Clinic and the Springdale Medical Centre in Brampton, Ontario.
Nancy Hillis
Michelle von Hahn
Alexa Everett
Laura Bolt