burdock
Meaning of burdock: A roadside weed eaten as a vegetable in East Asia, sold as a blood cleanser, and the plant that inspired hook-and-loop fastening.
Definition of burdock
Burdock is a tall thistle-like plant, Arctium lappa, recognized by its clinging burrs and its long slender taproot. The root is an everyday vegetable in East Asian cooking and is also dried for herbal preparations, taken traditionally for skin complaints and as a supposed cleanser of the blood. Its measured constituents include inulin, a fermentable plant fiber, along with various antioxidant compounds.
What is actually known about its effects?
Extracts show antioxidant activity in test tube systems, which is true of a great many plant extracts and does not by itself predict any effect in a person. Trials in people are few, small and mostly inconclusive. The one well-characterized component is inulin, a fiber that human digestion cannot break down but gut bacteria ferment readily, so eating the root behaves like eating a fibrous vegetable rather than taking a drug. The plant is also one ingredient of a long-promoted herbal cancer mixture, for which controlled evidence of benefit has never appeared.
Why has it caused poisoning?
Not through anything in the plant. Dried burdock root sold as tea has on occasion been contaminated with the root of deadly nightshade, which looks similar once cut and dried. People who drank it developed dry mouth, blurred vision, flushing, a racing heart and confusion, the classic picture of belladonna poisoning. The episodes say nothing about burdock and everything about loose dried plant material, where the buyer cannot verify what is in the packet. A separate consideration is that the plant belongs to the daisy family, so people reacting to ragweed and related plants may react to it as well.
How does it sit among other medicinal roots?
| Root | Plant family | Traditional claim |
|---|---|---|
| Burdock | Daisy | Skin complaints, cleansing the blood |
| Angelica root | Carrot | Digestive complaints |
| Senega root | Milkwort | Loosening chest congestion |
The botanical name carries its own description. Arctium comes from the Greek for bear, and lappa is the old word for a burr, which is what the seed heads are: dense clusters of hooked bracts that grip fur and clothing. That grip, examined under a microscope, is the origin of hook-and-loop fastening.
Also known as
Used in a sentence
The herbal history included burdock root tea taken daily.
Good to know
Cases of poisoning traced to burdock tea were caused by deadly nightshade root mixed into the product rather than by burdock itself, illustrating the identification risk carried by loose dried plant material.