This article was written for the first of Reforesting Scotland’s biannual journal of 2018. Reforesting Scotland is a membership organisation encouraging free and open debate on a wide range of forest and land issues. Over the years they have produced a range of projects, publications, policy statements and a wide variety of activities.
Monica Wilde reveals the surprising power of nettle seed – a food and an unusual medicine.
Common or stinging nettle, Urtica dioica, is a plant that needs little introduction. As children we quickly learnt to recognise them just so that we could avoid their itchy, burning sting. Nettles are part of our linguistic culture too. To ‘nettle’ someone is to annoy them; to ‘grasp the nettle’ is to face up to an unpleasant situation; ‘nettle rash’ or hives (urticaria) is a hot itchy skin condition; to ‘urticate’ is to cause a stinging or prickling sensation; and we even have a special word for whipping ourselves with nettles – urtification!
Nettle is fairly well-known as a highly nutritious wild vegetable. Many people have tried nettle and wild garlic soup (a foraging classic) and nettle leaf tea is widely available. However, the use of nettle seed is still fairly uncommon.
As the days lengthen the female nettle produces inconspicuous flowers quickly followed by green seed, drooping like heavily-laden catkins from the upper third of the plant. Over the summer the seed ripens and thickens. It is harvested when still green, before it starts to dry out and turn brown. It is crunchy and full of oil high in polyunsaturated fatty acids: predominantly linoleic as well as linolenic, palmitic, oleic and stearic acids. Our bodies use linoleic and linolenic acids to make the important essential fatty acids omega 3 and omega 6.
Harvesting
To harvest nettle seed I cut off the top third of each nettle and dry them on a sheet of brown paper in the sunshine, turning them occasionally until the leaves feel crisp. Then, wearing rubber gloves, I rub the seed off into a bowl. The green seed is quickly separated from any stray leaves or stems by sifting it through a standard steel-mesh kitchen sieve. If you are rubbing a lot of seed through a sieve, it is a good idea to wear a paper mask as airborne seed dust can be itchy.
For nettle seed that I plan to feed to other people I take the precaution of toasting it in a dry frying pan. The heat dissolves any stray ‘crystal hairs’ (cystoliths) and brings out their nutty taste, a little like toasted hempseed.
Versatility
Nettle seed tastes delicious. It can be substituted for poppy seed in crackers, oatcakes, bread, sprinkled with chopped nuts into salads or onto your porridge. Nettle seed will give you an energy boost and help to put you in a cheerful mood. For stimulating health benefits, take one to two spoons of fresh green or dried nettle seed a day (a standard heaped tablespoon is about 5 grams). You can chew up to 20 grams a day but many people find that just a teaspoonful is all they need. Try mixing nettle seed into yoghurt, a smoothie or add them to overnight oats. Do not try adding them to juices though as they float and are hard to drink! I also sometimes grind them and mix them with peanut butter or honey. Spread on toast or made into protein snack bars, is another delicious way of eating them. They also often end up being ground with seaweed, spices and salt as a seasoning.
Crush the seeds in a pestle and mortar, then infuse them in sunflower oil in a warm place for a week or two. This green oil makes a nice healthy salad oil or can be used with essential oils as an anti-inflammatory liniment for arthritic joints. In the past, horse traders would feed nettle seed to horses a few weeks before selling them. It helped the old nags become sprightly again with high spirits and shiny coats. Victor Hugo in Les Miserables confirmed that, “the seed of the nettle mingled with fodder imparts a gloss to the coats of animals”, and the seeds were once used to fatten up fowl.
Health benefits
Nettle seed is considered a Western ‘adaptogen’ (a botanical that greatly improves a body’s ability to adapt to a range of stresses), supporting the adrenal glands and endocrine system. It is used in herbal medicine as a tonic for fatigue and adrenal exhaustion; for people who are burnt-out, run down and low in energy, zest for life and libido.
For those interested in biochemistry, the ‘feel-good’ factor from eating raw, dried nettle seeds is caused by the neurotransmitters acetylcholine and serotonin, closely followed by choline and histamine. Acetylcholine binds to the mood receptors in our brains. It stimulates the autonomic nervous system, improves mood and heightens sensory perception, attention span, vigilance and intuition. Acetylcholine disruption may be a primary cause of depression. Serotonin acts on the central nervous system. It regulates mood, appetite and sleep, influences memory and learning. It is serotonin, along with histamine and formic acid, in nettle spines that causes the pain when you pick them. Incidentally, acetylcholine in nettle venom may well explain why the ancient practice of urtification for pain relief actually works! Nettle seeds also raise dopamine levels, creating pleasurable feelings.
Both the roots and seeds of nettle contain a protein called Urtica dioica agglutinin (UDA), which supercharges the body’s natural defences and immune system without raising pro-inflammatory cytokines. Nowadays, medical herbalists mainly use nettle seed to increase energy, as an anti-inflammatory and as a highly effective kidney restorative, slowing down renal failure. Modern clinical studies have shown that it also protects the liver, repairing it and restoring liver function after oxidative damage. Another macronutrient found in nettle seed is choline (a component of lecithin vital to liver function). Choline is sometimes used to treat liver cirrhosis and hepatitis. Studies have also shown that it is indeed anti-inflammatory and will soothe inflammation of the colon.
Nettle seed can be made into a tincture. In its most basic form, a tincture is just an alcoholic extract. In the 16th century, nettle seed was crushed and then soaked in wine; you can also infuse the crushed seeds in vinegar. Today, homemade tinctures can be made using 40 per cent strength vodka at a ratio of one part of seed to five parts of vodka by volume. The seed must be crushed first and soaked in the vodka for up to three weeks before straining off. At this strength, the usual dose is no more than two millilitres taken up to four times a day.
When added to herbal blends containing nourishing ‘nervines’ (herbs that specifically help support the nervous system) such as wild oat tops, nettle seed can be used to raise low mood, in winter blues or seasonal affective disorder (SAD). Try combining it with cleavers and seaweeds to increase a slow metabolic rate.
One note of caution: be careful when eating nettle seed not to exceed 30 grams a day. It can be over-stimulating and, like an amphetamine, prevent you from sleeping (although some people do experiment with nettle seed recreationally). A large 250ml cup of nettle seed tea (boiled fresh nettle seed in a 1:12 ratio (25 grams to 300 ml water) may keep you wide awake for several days!
So next time that you pass a derelict building site, jump a country ditch or take out the compost, watch out for the nettles and take a second look at this remarkable plant.
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Monica Wilde MSc FLS is a forager and research herbalist. She runs foraging walks and teaches wild food and wild medicine across Scotland. She also works at Napiers the Herbalists (www.napiers.net) and is a Fellow of the Linnean Society. References for this article can be supplied on request from hello@monicawilde.com
Good info. I missed the first harvest of small tops this spring. I let the plants go to seed to benefit pollinators then cut them down for compost followed by new young growth. Now I can get edible seeds
Wonderful information and adds to that I gained from Matthew and Julie Bruton- Seal’s marvellous Herbalist’s Bible. I shall definitely be gathering seed this year, thank you!
I read a study that Nettles are a phytoremediator. Taking up heavy metals and PCBs. I consider Urtica dioica my companion plant so I was a little upset to hear this as I’ve been using it, the whole plant, for years. I try to be really careful now where I harvest. Any thoughts on this?
It makes total sense to be aware of where you harvest and avoid picking on polluted areas. A small blessing is that you also need to factor in the fact that plants, like nettle, which are good at phytoremediation do so with the help of endophytic bacteria and catalytic enzymes. These help to degrade complex compounds removed from the soil – a kind of recycling into smaller parts. So they sensibly try not to store all of these in their tissues for long. Nevertheless, in polluted areas, the levels will be higher. Sadly it is not just wild plants and fungi but farmed food and the very water we drink that is at threat. And little is being done about the discharge and landfill of PCBs despite the growing awareness of their impact on health. The following article makes sobering reading: https://www.ciwem.org/the-environment/forever-chemicals-what-lies-beneath
Having found this wonderful site I shall harvest more of my nettles in the future. I have already been enjoying the tops in Spring as a vegetable or soup for years and sometimes make nettle tea or a rinse for shiny hair. Young nettles are very good in a quiche with goat’s cheese too. The rest I save for butterfly/moth caterpillars and the compost bin. I have seen finches and sparrows foraging on old dried stems in the winter so always encourage friends to keep some in their gardens rather than rip them all out.