The medicinal benefits of Mistletoe
During this holiday season, many homes have a sprig of mistletoe hanging, often in the entryway. Most equate its presence with a chance to steal a kiss; however, beyond an osculation opportunity, the festive-looking plant has other benefits, which many are unaware of.
Mistletoe is actually a semi-parasitic plant, which grows on a variety of trees including apple, elm, oak, and pine. American, European, and Chinese varieties exist. Mistletoe is a component of complementary alternative medicine (CAM). The plant is used in traditional Chinese medicine and was used by the Druids and the ancient Greeks. Since the 1920s, it has been studied for its applications in treating various form of cancer—in particular, solid tumors. For centuries, mistletoe has been used by European herbalists for the treatment of arthritis, epilepsy, headaches, and hypertension. Based on laboratory evidence of anti-cancer activity, mistletoe preparations are regularly prescribed in Europe for various types of cancers. In that part of the world, mistletoe preparations are regularly prescribed for various types of cancers as its extract demonstrates anti-cancer activity when used against cancerous cells in the lab.
The theoretical basis for mistletoe’s use for cancer treatment is based on the theory that it boosts the immune function, which stimulates the body’s immune cells. Mistletoe extracts are injected subcutaneously (under the skin), intravenously, or directly into the tumor. Some CAM investigators believe that the anti-cancer activity of mistletoe may be influenced by the host plant. For example, mistletoe growing on an oak tree may have a somewhat different chemical composition than mistletoe growing on an apple tree elm. To date, no definitive research has been conducted on which type of extract is of more potential benefit for which type of cancer.
European cancer research on humans regarding mistletoe is mainly conducted in Germany. A number of clinical studies have reported a beneficial effect of mistletoe against cancer; however, United States researchers have countered that the studies were either too small or poorly designed. A mistletoe extract known as Iscador was the subject of a clinical trial conducted between 1993 and 2000 on 800 patients with colorectal cancer. The patients were treated with chemotherapy and/or radiation therapy. The patients also received either Iscador or a placebo. The investigators reported that patients treated with Iscador had fewer adverse events, better symptom relief, and improved disease-free survival compared to patients who did not receive the mistletoe extract as adjuvant therapy. The investigators noted that mistletoe therapy reduces the discomfort and undesirable symptoms of other traditional therapies, such as chemotherapy.
In 2002, the National Cancer Institute (NCI) and the National Center for Complementary and Alternative Medicine (NCCAM) partnered to conduct a clinical trial of a mistletoe extract (Helixor A) in conjunction with the chemotherapeutic agent gemcitabine in patients with advanced solid tumors. The investigators found that the combination therapy had low toxicity and health benefits in almost half the patients. In this case, mistletoe demonstrated its value as an adjuvant, helping to modify the chemotherapy.
Currently, two research groups have “investigational new drug” approval from the Food and Drug Administration (FDA) to conduct clinical trials on the use of mistletoe extract for cancer. Their studies may lead to new therapies in the US; however, at present, the FDA does not recognize the use of mistletoe to treat any form of cancer. Furthermore, injectable mistletoe preparations cannot be sold in the United States.
Take home message:
Although mistletoe may have some anti-cancer benefits, the present state of research does not necessarily warrant a trip to Germany for mistletoe injection. Patients facing a terminal illness are very vulnerable to subjecting themselves to alternative therapy that may prolong their lives ore even cure them. However, for those that scoff at the use of plant extracts, it must be pointed out that a number of effective drugs are derived from plants. Two examples are digitalis and quinine, which are used for the treatment of heart disease.