Nettles - The healthy stingers

The plant urtica dioica, more commonly known as the stinging nettle, is a plant many of us are unpleasantly familiar with. The quite fitting name ‘nettle’ comes from the anglo-saxon word ‘noedl’ which means ‘needle’ and the latin ‘urtica’ means ‘to burn’. The plant is found worldwide but was originally native to Europe. At its tallest, the nettle grows to around two meters and are equipped with medium sized leaves. Despite many myths both the stem and the leaves are able to sting you as both are covered in the tiny needle-like structures called trichomes or spicules responsible for the burning sensation you get after contact with the plant.

The stinging trichomes of the nettle are a defense mechanism against animals looking for a plant snack. When touched, the tips of the trichomes penetrate the skin and break off. This leaves a mechanical irritation, however this is only the first step. The trichomes are hollow and function as hypodermic needles capable of injecting a cocktail of irritating and inflammatory chemicals. One of the chemicals injected are formic acid which is also present in bee venom and used by ants as a defense. Some of the other substances in the mix are histamine, acetylcholine and serotonin. The introduction of these chemicals gives the well known burning and itching sensation known as contact urticaria which can last for up to 12 hours. In some rare cases where people are allergic to the nettles toxins the burn could potentially be fatal.

However, despite the sinister capabilities of this plant, it also has a positive side. The plant is incredibly nutritious with a high content of vitamins, minerals and fatty acids. The concentration is especially high in the leaves which can, and have been, used for human consumption in centuries, especially in the form of a nettle soup. Several studies have also found some of the compounds in the nettle to be strong antimicrobial agents able to kill both gram-positive and gram-negative bacteria. Some studies even found the antimicrobial abilities to be greater than some antibiotics, making the nettle and its compounds very interesting in medical and pharmaceutical research.

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