Mistletoe (Viscum album)
This telltale sign of the holiday season does more than inspire smooching

By Laurel Vukovic

What It Is
Mistletoe is a parasitic evergreen plant that grows primarily on deciduous trees. European mistletoe (Viscum album) is the variety most commonly used in herbal medicine. The American species (Phoradendron spp) appears to contain similar active compounds, but has not been widely studied. Both types have leathery green leaves, a rounded form, and small, sticky white or red berries in the fall.

History And Folk Remedies
The druids and other ancient Europeans revered mistletoe as a sacred plant that protected them from evil. Kissing under mistletoe may stem from the belief that mistletoe was related to fertility, or from a tradition of soldiers calling a truce whenever they passed beneath the leaves. For centuries, the herb has also been used for treating a variety of maladies, including epilepsy, nervous tension, headache, hypertension, and cancer.

Kissing under mistletoe may stem from the ancient belief that the plant was related to fertility. Why It’s Used
Popular in Europe, mistletoe is primarily used in contemporary herbalism for hypertension and as a complement to cancer therapy. For treating hypertension, mistletoe is taken orally and is usually combined with other blood-pressure reducing herbs, such as hawthorn and garlic. It should only be used under the supervision of a qualified health care professional. Since the 1960s, more than 30 primarily German clinical studies have looked at mistletoe as a complementary cancer treatment. Many of the studies show that the herb is associated with higher survival rates and improved quality of life, including increased appetite and reduced pain. When treating cancer, the herb is given by injection; commercial extracts are available only in Europe. At this time, the FDA approves injectable mistletoe for clinical research only.

Scientific Support
Although mistletoe contains compounds that both increase and decrease blood pressure, animal studies indicate that, overall, the herb lowers blood pressure. Mistletoe’s purported cancer-fighting properties have been researched in test-tube, animal, and clinical studies. Mistletoe extracts may fight cancer by stimulating the immune system, killing cancer cells, and reducing tumor size. The herb also appears to counter the immune-suppressing side effects of chemotherapy and radiation. German researchers have found that patients treated with mistletoe lived approximately 40 percent longer than those not given the extract (Alternative Therapies in Health and Medicine, 2001, vol. 7, no. 3). Commission E, the FDA’s German counterpart, approves mistletoe as a complementary cancer treatment. However, a recent report suggests that many initial studies were flawed, indicating more research is needed (International Journal of Cancer, 2003, vol. 107, no. 2).

Side Effects
Injectable mistletoe extracts commonly cause slight fever, chills, headache, and soreness at the injection site. These symptoms are considered desirable because they indicate a heightened immune response. Although rare, there have been cases of severe allergic reaction to the injectable extract. Oral preparations must be used under a health care practitioner’s guidance.

Precautions
Fresh mistletoe is generally regarded as toxic, so don’t ingest the fresh plant or berries. Because mistletoe may stimulate uterine contractions, avoid it if you’re pregnant. Also, people taking MAO inhibitor antidepressants should not take mistletoe because the interaction between the two can cause dangerously elevated blood pressure.

Forms
When treating hypertension, mistletoe is usually taken as a tea or a liquid extract, always under the guidance of a health care practitioner. For cancer, injectable mistletoe is used for several months or years.