Mistletoe — Cancer Fighter or Cause of Tumors?

Disclaimer: Results are not guaranteed*** and may vary from person to person***.

When you hear “mistletoe,” you think of the traditional Christmas ornament, which is often hung from the ceiling — when two people pass underneath the sprig, they must kiss. However, there’s a lot more to it than that. In fact, in Europe, mistletoe considered a treatment for cancer.

 The mistletoe is an evergreen plant that is often parasitic. The seeds of this funny-looking shrub are spread to other trees by birds, where they attach themselves to a branch and grow, sucking out the host tree’s nutrients through the mistletoe’s root system. The specific species of note is the one that grows in Europe, Viscum album, and not the species seen commonly here in North America.

 As a herb, it’s long been used to help with hypertension, arthritis, headaches, and seizures. Injections of the extract are now prescribed in Europe to help treat cancer. In Germany, the medical community’s confidence in mistletoe’s anticancer abilities is so high that prescriptions are covered by the country’s health insurance system. Note that the plant is actually poisonous to humans in its unprocessed form.

 According to the National Institutes of Health (NIH), studies (which are mostly European) have found that mistletoe could destroy cancer cells and help the body fight off the disease by boosting the immune system. However, many of these studies are not considered strong evidence, as they did not use a control group or only looked at a small group of subjects.

 In fact, a recent case, reported in the British Medical Journal, seems to indicate that mistletoe treatment could actually trigger the formation of a tumor. In Wales, a 61- year-old woman, who had had an operation to remove a breast cancer tumor, was discovered to have a tumor in her abdomen in a follow-up appointment. The tumor was removed and examined — it was found to be benign. After ruling out other potential causes, the doctors found out that the woman had been receiving mistletoe injections as a separate therapy for her breast cancer.

 As the location of her abdominal tumor seemed to line up with the injection site, the doctors concluded that the mass was likely an inflammatory response to the mistletoe extract. Their conclusion is also backed up by two other documented cases, involving a total of eight patients who seemingly developed inflammation as a response to mistletoe treatment.

 Before you go munching on mistletoe berries or leaves, remember that it’s a poisonous plant. Furthermore, mistletoe extract is not yet available in North America as a treatment for cancer, as it has not been FDA-approved. Currently, the National Center for Complementary and Alternative Medicine (NCCAM) is launching a clinical trial on the effects of mistletoe and the chemotherapy drug gemcitabine on cancer. We’ll have to wait and see what the findings are.

 So, in light of the weakness of evidence on whether mistletoe is more harmful than it is helpful when it comes to cancer, we need more good-quality studies on the subject. The report of the patient who seemingly developed a tumor in response to mistletoe injections is not a definitive strike against the herb; it is, however, a warning to anyone undergoing any kind of treatment.

 If you’re receiving standard medical treatment for some kind of condition, you must inform your physician of any and all complementary treatments or therapies you are trying, no matter how insignificant they seem. Your doctor needs to know about every aspect of your health and treatment in order to provide you with the proper care.