Q. Can mistletoe be used to treat cancer?

A. The Celts in Europe used mistletoe in religious rituals more than 2,000 years ago. They named the plant "mistletoe" to mean "all healer." It was used for treating high blood pressure, anxiety, arthritis and vertigo. Scientific evidence does not support these uses.

A liquid extract from the mistletoe plant has been used in Europe as a cancer treatment for 75 years. Commission E (Germany's equivalent of our FDA) has approved its use to treat some of the side effects of cancer therapy. It has not been approved as a cure for cancer. For cancer treatment, it is taken by injection.

The American mistletoe plant is not the same as European mistletoe. American mistletoe has no medicinal properties and is poisonous if eaten.

Experiments in test tubes and animals show evidence of mistletoe's anti-tumor activity. Experiments in people have shown mixed results. A review of 21 studies using mistletoe alone or with chemotherapy and radiation was recently completed. Researchers wanted to see if mistletoe increased survival times, enhanced tumor response to therapy, or reduced adverse effects of anti-cancer drugs. Some studies showed positive results, especially in improving quality of life during chemotherapy, but many used questionable methods and are not considered scientifically dependable.

The National Institute of Health is recruiting participants for a large clinical trial in which mistletoe will be combined with the chemotherapy drug Gemcitabine. Their study is designed to eliminate the weakness of previous studies.

Caution should be used in buying any over-the-counter mistletoe products. Mistletoe is not approved by the FDA as a treatment for cancer or any other medical condition. Over-the-counter products can vary in purity, type of mistletoe, and strength. It is not recommended that homemade cancer remedies be made from mistletoe extracts or berries.

Bottom line: There is some potential benefit to mistletoe, most likely in combination with chemotherapy agents. More research is needed before it becomes standard therapy. For now, it's best to stick to kissing under the mistletoe.

Amy Tousman is a registered dietitian and certified diabetes educator with Nutrition Unlimited in Kailua. This column is not intended to provide medical advice.