When I decided to write a Christmas story—which was originally supposed to be a short story, then grew into a novella, and finally became a short novel—I started looking around for medicinal properties of spices commonly used in holiday cooking. Ginger, for example, makes a brief appearance in A SNOWFLAKE AT MIDNIGHT, as it’s reported to have anti-inflammatory and anti-nausea properties, among others. But spices didn’t quite work for what I had in mind.
I turned to plants associated with Christmas: holly, ivy, and of course, mistletoe. Everyone thinks of mistletoe for kissing, right? A classic Christmas scene. But mistletoe hasn’t always been just about stealing kisses—it has a long history in folk medicine, going back at least 1,000 years. Originally, it was believed to protect against evil spirits and promote fertility—hence the kissing tradition.
What is mistletoe, really?
For those of us in the United States, it’s worth noting that the mistletoe we see here is different from the European variety. When I lived in Savannah, Georgia, I noticed these strange ball-like plants high up in the winter trees—I learned that was mistletoe. But the North American mistletoe isn’t the same species as European mistletoe; it’s actually from a different plant family altogether. The term “mistletoe” gets applied to plants that look similar and have similar growth habits.
European mistletoe, native to Britain and much of Europe, is Viscum album. It was introduced to Northern California around 1900, but I’m not sure if it has spread to places like Georgia yet. If you know, I’d love to hear!
Today, we’ll focus on Viscum album, the European mistletoe with medicinal properties.
Characteristics of European Mistletoe
Viscum album has smooth, oval, evergreen leaves arranged in pairs along the stem. It produces waxy white berries that appear in clusters of two to six pairs, ripening in winter. Mistletoe grows on various trees—oak, apple, maple, birch, ash, and lime, to name a few. It’s semi-parasitic, using a root-like structure called a haustorium to tap into the tree’s vascular system. Because of this, heavy mistletoe infestations can harm trees, especially young or small ones.
Here’s a little diversion: Those sticky white berries were historically used (along with boiled holly bark) to make birdlime—a sticky substance spread on twigs to trap small birds, which were then cooked. A nasty trick, now illegal in most countries. During World War II, birdlime inspired a “sticky bomb” grenade designed to stick to tanks, but it had issues like sticking to the user instead of the target. The sticky traps reminded me of The Twits by Roald Dahl, where birds get caught in glue and end up in a pie—if you haven’t read it, I’ll link it in the notes.
Back to Viscum album. Its use as a cure dates back to the Druids, who had an oral tradition, so we rely on Roman author Pliny the Elder for records of their practices. The Druids revered the oak tree as sacred, so mistletoe growing on oak was considered the most potent. They had a special ritual: white-robed Druids used a golden sickle to cut the mistletoe, which was caught in a white cloth because it was believed that if the plant touched the ground, it would lose its power.
Mistletoe as a Cure-All?
The Druids thought mistletoe was an antidote to poisons and a fertility booster—not just for humans but animals too. There’s some evidence it can stop uterine bleeding, like painful menstruation or threatened miscarriage. It was also believed to cure epilepsy. While mistletoe does have neurological effects, these are poorly understood and it’s definitely not an epilepsy cure.
I liked the idea of using mistletoe’s fertility and epilepsy connections in my story, but the research wasn’t strong enough and my plot ideas didn’t develop well from that.
Then I found studies suggesting mistletoe might influence the immune system. And here’s the kicker: poison is in the dose. Mistletoe is definitely poisonous if consumed in large amounts—don’t try that! It contains cytotoxic lectins that can inhibit protein synthesis and kill cells if taken in high doses.
But at the right dose, mistletoe lectins can boost immune function by increasing the number and activity of natural killer cells and other immune cells. Mistletoe extract injections can cause mild eosinophilia—increased allergic/inflammatory cells. It’s also been shown to have nonspecific antitumor activity, meaning it doesn’t target a particular cancer but can stimulate some cancer-fighting responses.
In ancient times, cancer treatments were topical—treating visible tumors on the skin rather than internal cancers. This fits with the topical nature of mistletoe therapies in my story.
Is mistletoe used in modern medicine?
Not much in the US or Canada. But in Europe, commercial mistletoe extracts are available as adjuvant therapies—meaning they’re used alongside, not instead of, standard cancer treatments. Please don’t think the recipe in my book is a real skin cancer cure—always see your doctor for medical issues.
One fascinating case report describes a 78-year-old man with cutaneous squamous cell carcinoma (a skin cancer common on sun-exposed areas). He refused surgery, and instead underwent 10 months of mistletoe extract injections at the tumor site, resulting in spontaneous remission and no recurrence after four years.
This case inspired me to include mistletoe therapy in my story.
What about the tree the mistletoe grows on?
Mistletoe is parasitic, so it taps nutrients from its host tree. The species of tree affects the chemical composition of the mistletoe plant, much like different vitamin supplements vary in ingredients.
Companies producing mistletoe extracts specify which host tree the mistletoe came from and when it was harvested. For example, Iscador, a patented mistletoe extract, is made from mistletoe growing on apple trees.
I wanted my mistletoe to grow on English oak—the sacred Druid oak. So I found a paper analyzing phenolic acids (one type of active compound) in mistletoe from six different trees: Norway maple, rowan, cottonwood poplar, European pear, apple, and English oak (Quercus robur).
The profiles differed—each mistletoe extract was unique depending on its host tree.
However, mistletoe growing on oak trees is rare in Britain—only 11 oak trees had mistletoe in 2000, mostly in Herefordshire. Perhaps commercial producers use apple trees because oak-hosted mistletoe is too scarce.
This rarity inspired the “what if” in my story: what if there was a Druid Oak growing in Hyde Park, London, hosting medicinal mistletoe?
