Dock leaves won't help with nettle stings – but you can eat them
After a run-in with a stinging nettle, you’re invariably instructed to locate, and rub the affected area with, a dock (or docken) leaf to soothe it. It’s a long-held folk remedy, but does it actually work? And what is a dock, anyway?
These questions were prompted while on a walk with friends last weekend. One of us got stung, and so began the dock hunt. But we soon realised we had very different ideas of what one looked like. Turned out some of us had gone through life rubbing any old leaf on our skin – thankfully to no ill effect.
There are about 200 species of docks and sorrels, which are closely related to buckwheat, knotweed, and rhubarb. Of those, you’re most likely to see just two: the broad-leaved dock and the curly dock.
But do docks help with nettle stings?
No is the short answer.
When you brush against a nettle, its fine “hairs” (actually sharp, hollow cells that act like needles) break and inject irritants – a mixture of histamine, serotonin, acetylcholine, and various acids – into your skin.1
The idea is that the sap from a dock leaf is alkaline so it neutralises the nettle’s acid, and that it contains a natural antihistamine to reduce the irritation. This is wrong on both counts: dock sap is actually slightly acidic, and there’s no evidence that it contains any antihistamines.
At best, it works as a placebo, and the act of hunting for the plant – and the squashing and mashing rituals – distracts from the pain.
You can eat them, however. The leaves are tart and lemony, and were apparently quite a popular foodstuff during the Great Depression. Make of that what you will. It won’t save you from the physical pain, but you can drown your sorrows by munching down on a few of its lemony leaves.
But there is a more promising alternative, which is just as common and, crucially, appears to have at least some remedial ability: the plantain.
Like docks, there are two common ones: the greater plantain and the ribwort plaintain.
You will, knowingly or unknowingly, have seen these plants millions of times. They’re incredibly widespread, springing up all over lawns and verges or erupting through cracks in the pavement. Apparently they’re very eager to help.
As with docks, you’re meant to crush a leaf or two and rub it on nettle stings (or wasp and bee stings, insect bites, rashes) to soothe the affected bit of skin.
The evidence for the actual mechanism for this is rather shaky, but plantain does at least contain compounds that aid in the treatment of wounds (like antibacterials and anti-inflammatories), so it’s more likely to help than dock.2 You can eat plantain leaves too, but they taste awful.
So, in the name of scientific research, next time you’re stung by a nettle, locate a plantain, rub a few leaves on the affected area, and see if it works. And if you happen to find a dock plant at the same time, hand a few dock leaves to a similarly afflicted friend for a quick A/B test, or just chuck back a few to toast the occasion.
When life gives you lemony-tasting leaves, eat them, don’t rub them on your skin.
If serotonin and acetylcholine ring a bell, it’s because they’re both key neurotransmitters. They send signals to cells all over our body to alter our mood, digestion, heart rate, and much else besides. Serotonin is commonly (and inaccurately) known as one of the “happy hormones”, along with oxytocin and dopamine.